
File: MICROS,    Node: Top,    Up: (DIR),    Next: Add

This file contains information on various micro-processor systems.
It is not complete in any sense of the word.  It is also not
guaranteed to be correct.  Comments, bugs etc. to GZ@MIT-MC.

You can walk through this whole file by just using the N command.

* Menu:

* Add::			How to make additions/changes in this file.

* CP/M::		A general description of this popular micro
			operating system.

* Software::		Reviews of various software products
			Ain't nothin' here yet!

* Hardware::		Reviews of various hardware (add-on) products 
			Ain't nothin' here either!

Microcomputer systems:

* Acorn Atom::
* Apple II::
* Apple III::		
* Atari 400/800::	The Atari 400 and Atari 800 systems
* Compucolor II::
* H89::			Heathkit H89, also known Zenith Data Systems
			 Z-89. 
* Micro Ace:		Sinclair ZX80, Micro Ace is the kit form of
			 the ZX80. 
* Micro Chroma 68::
* Osborne 1::
* OSI::			OSI Superboard, C1P, C2-4P, C4P, C2-8P and C8P
* PDP-11/23::		PDP-11/23 running RSTS/E
* SD Systems Z-80::	The SD Systems Z-80 Starter Kit
* Sinclair ZX80::
* Sorcerer::		Exidy Sorcerer I and Sorcerer II
* Superbrain::
* Sym-1::
* SWTP 680X::		SWTP 680X running the FLEX operating system
* TRS80 I::		TRS-80 Model I (Level I and II)
* TRS80 II::		TRS-80 Model II
* TRS80 Color::		Radio Shack's color computer

* HomeBrew::		Descriptions of some home-brew systems.


Node: Add,       Previous: Top,     Up: Top,      Next: CP/M

How to make changes to this file:

If you find a mistake in some description, or find some information is
missing, just go ahead and edit it in.  If it is anything which could
be vaguely disputable, put your name right by it, e.g. 
	[Actually that board is a piece of junk - GZ, 01/31/82]

Generally it is better to add your bit to whatever is there, rather
than deleting something, unless the given information is absolutely
and non-controversially wrong.

Descriptions of new systems: Below is a list of some categories which
have been found to be useful in writing up a system.  Not all
categories apply to all systems, so feel free to skip some, as well as
add some of your own.

When adding a node, make sure not to change the truth value of the
following statement:
 "This entire file can be walked through just using the N command"

The menu is in alphabetical order.

Mail a message to me (GZ@MIT-MC) saying that you've added a new node.

Remember to :INSTALL the changed file on all four ITS's.
	 [Actually only half still exist -MAP 11:51pm  Friday, 3 February 1984]

For CP/M systems:
Since there is a separate node for CP/M (*note CP/M: CP/M.) you need
not really describe CP/M software, just make a footnote like the one
above.  However you might describe any restrictions on using standard
CP/M software with your system.

If you feel queasy about hacking the file, just mail any comments/new
descriptions to me (GZ@MIT-MC) and I'll put them in for you.

Sample categories:

Name: 	Name and model of microcomputer - to be used as the INFO node
	name. 
Users:  People who will supply more info about this machine
	(net addresses).
Manufacturer/Distributors: Where you can buy this system or at least
	obtain additional info.  US Mail addresses, telephone numbers,
	etc.
Type of System: All-In-One vs. Distributed / SingleCard vs. CardFrame
Target Users: Consumer, Business, Hacker, Novice, etc. Expertise
	needed to use it.  Comments on documentation.
Price:  for lowest level system, example prices for add-ons
Bus: 	connection to outside world exclusive of I/O ports
CPU: 	the chip + clock rate
Memory: RAM & ROM included, maximum possible, what's in the ROM
Display: type, #lines, #chars, graphics, resolution, colors
Keyboard: description, keypads, special functions, missing keys.
I/O Ports: Parallel, serial, RS-232, etc.
Mass Storage: Cassettes, Disks, capacities. What's standard +
	compatible extensions available.
Peripherals: Printers, Modems, etc.  Availability, ease of
	interfacing, etc. 
Other Hardware: Other hardware features not fitting in the above.
Operating System: Monitor, DOS.  Description.
Languages, Assemblers:
Editors & Text Processors:
Communications Software: Terminal emulation programs, other...
Application Programs: Games, Mailing lists, databases, etc.
Other Software: any other software features not fitting in the above.
Users' groups: names/addresses of any users' groups, magazines devoted
	to this system, etc.
Comments: Evaluation, miscellenious comments, random features,
	misfeatures, known bugs, etc.

Node: CP/M,       Previous: Add,       Up: Top,     Next: Software

CP/M is a single user, single task operating system for 8080/8085/Z80
based microcomputers. It is the most widely used disk operating system
for microcomputers and hence "CP/M compatible" is the defacto software
standard. CP/M was written and is currently supported by DIGITAL
RESEARCH, PO Box 579, Pacific Grove, CA 93950 (408) 649-3896. Current
versions are 1.4 and 2.2. Version 1.4 is for low to medium capacity
floppy disks, while 2.2 is for high capacity floppys and hard disks.
Version 2.2 also incorporates some improvements which handle directory
attributes for MP/M (Digital Research's multi-user/tasking OS)
compatibility.

The standard distribution/exchange medium is an eight inch, single
density, single sided, IBM 3740 format floppy diskette. Other formats
including double density, hard disk, and 5 1/4" diskette may be used.
CP/M systems and programs on non-standard formats are available from
LIFEBOAT ASSOCIATES, 1651 Third Ave., New York, NY 10028, Phone (212)
860-0300.  See their advertisement in BYTE for a current list. Prices
for CP/M start at $100 for standard V1.4 and $150 for V2.2.

An active users group (CPMUG) exists. Their activities are covered in
a magazine called Lifelines (from Lifeboat). CPMUG has released at
least 42 volumes (disks) of public domain software. Hundreds of
programs are available including: assemblers, editors, compilers,
interpreters, text processors, disassemblers, games, communications
software,graphics software, music software, cross assemblers and
simulators for other processors, and utilities galore. All volumes are
available free+media+ postage/service. This software and more is
available via modem from Remote CP/M Systems around the country. On
ITS directory MC:CPM; there are some programs and downloading
facilities as well as more information about CP/M and Remote CP/Ms.

				MEADER@MIT-AI 02/07/81

* Menu:				None of these are written yet!!
				Volunteers, anyone?
* Users::
* MP/M::
* Text Processors: Text,	   Editors, text justifiers, spelling
				   checkers and so on.
* Language Processors: Languages,  Assemblers, compilers, linkers,
				   interpreters ...
* Debugging Tools: Debug,	   Debuggers, disassemblers, etc.
* Cross-assemblers::
* Database Systems: Databases,
* Communications Software: Communications,
* Financial Applications: Financial,
* Sorting Utilities: Sorting,
* Misc Utilities: Misc,

Node: Users,       Previous: CP/M,        Up: CP/M,       Next: MP/M

		  << Please write me !!!>>

Node: MP/M,	  Previous: Users,	  Up: CP/M,	  Next: Text

		  << Please write me !!!>>

Node: Text,     Previous: MP/M,        Up: CP/M,      Next: Languages

		  << Please write me !!!>>
		     --> starting Whitcher, from multics
			 will give brief descr. of known tools

Vedit, Vedit plus

       full-screen programming editor, also available on pcdos etc.
I can only speak from experience on Vedit plus, editor supports 
mem-mapped crt controllers and a massive array of terminals, 8080 or
z-80 object code. The object module is not small (23k vedit+ ~17 
vedit) the enhanced version offers 37 text registers, all of which
may act (simultaneously) as full edit buffers (vedit has only 1 edit
buffer). Vedit + also provides a "powerful" (read obscure) command
language emacs macros are superior, problem is vedit macros only work 
in "command mode" (a super-sophisticated line editor) I have not used
teco, but looking at emacs, I prefer the design. 

  Vedit can be made to look ~ like emacs, the conventions on (e.g.)
where a word begins/ends are different, and not very consistent. it
does handle the screen well and very fast (knows how long to delay
cursor at 19.2kb etc.)
Node: Languages,     Previous: Text,     Up: CP/M,       Next: Debug

		  << Please write me !!!>>

Node: Debug,  Previous: Languages,  Up: CP/M,   Next: Cross-assemblers

		  << Please write me !!!>>

Node: Cross-assemblers,  Previous: Debug,  Up: CP/M,   Next: Databases

		  << Please write me !!!>>

Node: Databases, Previous: Cross-assemblers, Up: CP/M, Next: Communications

		  << Please write me !!!>>

Node: Communications,  Previous: Databases,  Up: CP/M,  Next: Financial

		  << Please write me !!!>>

Node: Financial,  Previous: Communications,  Up: CP/M,  Next: Sorting

		  << Please write me !!!>>

Node: Sorting,    Previous: Financial,    Up: CP/M,     Next: Misc

		  << Please write me !!!>>

Node: Misc,      Previous: Sorting,       Up: CP/M,      Next: CP/M

		  << Please write me !!!>>

Node: Software,   Previous: CP/M,      Up: Top,     Next: Hardware

		  << Please write me !!!>>

Node: Hardware,     Previous: Software,     Up: Top,     Next: Acorn Atom


		<<Please write me!!!!>>

Node: Acorn Atom,   Previous: Hardware,   Up: Top,   Next: Apple II

Users:	DAVROS@MIT-AI
Manufacturer: Acorn Computer, Cambridge, UK.
Distributor: Climar Torch Group, Toronto, Canada (Current nearest,
	     we think)
Type: 	All-In-One (Bar a few bits; single board)
Target: Home/ hacker/ lab instrument (?)
Price:	(Not known for USA/Canada). 140 pounds sterling minimum
CPU : 	1MHZ 6502
Memory: 8K BASIC in ROM, 4K floating point in ROM (extra),
        4K DOS in ROM (extra)
	2K RAM, extensible to 12K (onboard), maximum 37K RAM (with a
	struggle).
Display: Uses MC6847, generates NTSC picture, max 8 colours in some
	 modes, max resolution 256 x 192.
	 Text 20 lines x 32 characters
Keyboard: Built into box, full ASCII, sprong contacts.
I/O:	6522 via on board (extra)
	Parallel printer buffer (extra)
	nurdle (extra)
	"mass store" cassette also disc available.
Peripherals: Easy to interface, but no RS232.
Operating System: ACORN DOS.
                  Really hack level (More BASIC.
                  BASIC interpreter, built in assembler.
Languages: BASIC, FORTH, Pascal (mostly ACORN versions).

We can try to get further info if you are interested.

				DAVROS@MIT-AI, 03/13/82


Node: Apple II,     Previous: Acorn Atom,   Up: Top,   Next: Apple III

Users: ROBG@MIT-DM, INFO-APPLE@MIT-MC
Target Users: The Apple II is fairly easy to use right from the start,
	with just a little experience.  The manuals are fairly
	complete and well written.  However, to begin journeying into
	the world of assembly language you need patience and more
	experience with computers.  All in all, it is a good choice
	for an all around fun, educational and/or business machine.
Price: $1000-$1150 for the basic system (16K)
CPU: 	6502
Memory: The basic system comes with 16K of RAM.  It is expandable to
	48K, or 64K if you implement the Pascal Language System.
Display: 40x24, all UPPER CASE.  However, there are numerous ways
	(both through software and hardware) to get around this.
	There are many companies that sell 80-char boards (upper/lower
	case), so if you are worried about using it as a terminal, it
	is really not a problem.  There are very limited features for
	correcting text once it has been entered.  Other than four
	escape codes for up,down,left, and right, there are no insert
	delete,etc commands. This, however is also software
	correctable.
Mass Storage: The basic means of storing and retreiving programs comes
	from the tape player.  However, Apple sells the 'DISK II'
	which is a 5-1/4 [5-1/2] inch mini floppy disk drive. It
	retails for $600 with the controller card.  Add-on disks (up
	to 7) are available for $390-$430.
Operating System: With the Apple II you get Integer Basic in ROM, and
	will have to buy the Floating Point Basic if you want it.
	With the Apple II Plus, you get Floating Point in ROM and have
	to buy the Integer Basic if you want it.  The differences
	between the languages are many, so I will not go into them
	here.
Languages: You can get Pascal, Z80, Fortran, and now Cobol for
	operating systems.
Software: There are endless companies that are constantly releasing
	new and exciting software, from text editors to games, to
	utilities.
Peripherals: There are many, many add ons available, so I will only
	list a few here.  There are many printers, hard disk drives,
	extra slots, modems [specifically, the DC Hayes Micromodem
	II], time clocks, and many others.  There are numerous
	hardware ''Houses'' which sell parts for the Apple.  I have
	never had a problem getting parts and/or service for my Apple,
	and I am sure that this is true with almost every Apple owner.

				ROBG@MIT-DM, 01/11/81

Node: Apple III,    Previous: Apple II,  Up: Top,  Next: Atari 400/800


Users: INFO-APPLE@MIT-MC

This is a reproduction of a 'facts' sheet being distributed by
the BYTE SHOP in Hayward  -- SHL@MIT-MC 06/18/80

			APPLE III facts sheet
			----- --- ----- -----

Size:		17.5" wide (44.45 cm), 18.2" deep (46.22 cm),
		4.8" tall  (12.2  cm)
		Cast aluminum base with molded plastic cover.

Weight:		26 lb  (11.8 kilos)

Processor:	Apple designed processor utilizes 6502A as one of
		its major components.  Other circuitry provides
		extended addressing capability, relocatable stack and
		zero page, and memory mapping.

Emulation mode: provides hardware emulation of 48K byte Apple II or
		Apple II plus.  Allows most Apple II programs to run
		without modification.

Clock speed:	1.8 MHZ with video off, 1.4 MHZ average
		1.0 MHZ in emulation mode

Main memory:	96K (98,304) eight-bit bytes minimum
		128K (131,072) bytes maximum
		Dynamic RAM memory

ROM memory:	4K (4096) bytes used for self-test diagnostics.

Power supply:	High-voltage switching type. +5, -5, +12, -12 Volts 

Mass storage:	One 5.25" floppy disk drive built-in
		140K (143,360) bytes per diskette
		Up to 3 additional drives can be connected by daisy
		chain cable (572K bytes on-line storage) 

Keyboard:	74 keys (61 on main keyboard, 13 on numeric pad)
		Full 128 character ascii encoded.
		All keys have automatic repeat.
		Three special keys:  SHIFT, CONTROL, ALPHA LOCK
		Two user-definable "APPLE" keys
		Four directional arrow keys with two-speed repeat
		Four other special keys:  TAB, ESCAPE, RETURN, ENTER

Screen:		Three upper/lower case text modes:
		 80 column, 24 line black-and-white
		 40 column, 24 line 16 color foreground and background
		 40 column, 24 line black-and-white
		All text modes have a software-definable 128-character
		set (includes upper and lower case) with normal or
		inverse display. 

		Three graphics modes:
		   280X192, 16 colors (with some limitations)
		   140X192, 16 colors
		   560X192, black-and-white
		   Plus APPLE II modes

Video output:	RCA phono connector for NTSC black-and-white
		Composite video
		DB-15 type connector for:
		   NTSC black-and-white composite video
		   4 TTL outputs for generating RGB color
		   Composite sync signal
		   NTSC color composite video
		   +5, -5, +12, -12 Volt power supplies
		Color signals appear as 16-level grey scale on
		black-and-white video outputs.

Audio output:	Built-in 2" speaker.
		Miniature phone-tip jack on back of APPLE driven by
		six-bit digital/analog converter or fixed-frequency
		"BEEP" generator.

Serial I/O:	RS-232C compatible, DB-25 female connector
		Software selectable baud rate and duplex mode

Joysticks:	Two DB-9 connectors for two joysticks with
		pushbuttons.

Printer:	One DB-9 connector (shared with second joystick)
		for APPLE SILENTYPE printer

Clock:		Can be set and read from programs
		Powered by long-life replaceable watch batteries
		Keeps track of month, date, day of week,
		and exact time to 1/1000th of a second.

Expansion:	Four 50-pin expansion slots inside the cabinet

SOS:		Sophisticated operating system handles all system I/O.
		SOS can be configured to handle standard or custom I/O
		devices and peripherals by adding or deleting
		"device drivers".

		All languages and application programs access data
		through the SOS file system

Languages:	APPLE Business Basic, Pascal, FORTRAN (4th quarter)

The cost is expected to be between 4400 & 4500.


Node: Atari 400/800, Previous: Apple III, Up: Top, Next: Compucolor II

			 Atari 400 and 800

Users: PALEVICH@NBS-10
Manufacturer: Atari
Target Users: The thing to buy for hobby/home video game hacking.
	Probably also the best for educational purposes.  Not for the
	hardware hackers.  The documentation is excelent, idiot proof,
	glossy paper, color manuals, CAI tutorials, operating system
	source, etc.  Reasonable documentation of hardware is not yet
	widely available.
Price:  $600 ($450 if you try)
CPU: 	6502B at 1.79 Mhz.
Bus:	The peripherals communicate over an extremely flexible serial
	i/o bus, with so many hacks and interrupts that the
	documentation on it (which, I understand they are working
	furiously at, in order to get it out to their customers) is
	about 6" already.
Memory: 8K RAM, 10K ROM Operating system, 8K ROM Basic.
	The 800 may be expanded to 112K of RAM, the 400 to 32K.
	The latest rumor is that the 800 can really be expanded to
	192K (bank select of course).
Display: You supply the TV (preferably color).  The unit comes with a
	video-out line.  The graphics hardware included with the Atari
	is incredible.  You can do just about everything.   Just look
	at Star Raiders.
	You can't really get more than about 53 legible characters per
	line even if you use the super dense graphics mode and plot
	them yourself.
	The characters are actually user definable - just set up your
	date (8 bytes per char) and change one register.
	Other hacks are that a line of text, or a whole screen, may be
	inverted (UPSIDE DOWN, not in color), or you may scroll both
	vertically and horizontally, or enable interrupts for
	everything from video retrace to serial character received to
	depression of the break key. And so on and on.
Keyboard: Comes with the unit.  The 400's keyboard is awful. It is
	monopanel with all the tactile feedback of a formica tabletop
	(it is science-fictiony looking, though).  The 800 has a very
	nice real keyboard to it.  It is possible to hook up the
	keyboard of your choice to either one if you are willing to
	write the software for it.
Mass Storage: Cassette recorder for $70, you must buy Atari's because
	of the 15-pin plug. 
	Disks ($600 for 80k 5" floppy, $1000 for 120Kx2 drives, each
	system can have up to 4 drive units (even 4 2-drive units for
	8 disks. . .)) 
I/O Ports: High speed serial (19.2Kb)  for everything.
	RS-232C interface is $250 -- 4 ports, one of which can also
	drive teletypes.
Peripherals: Light pen $70 -- 160 x 96 resolution, hardware, 60hz
	sample rate.
	Printers -- all sorts $400 up.
	Joysticks, game controllers $20 each/per pair.
Software: Basic, Assembler/Editor, Telelink (TTY emulator), Visicalc,
	DOS, Pilot, Pascal, Calculator, etc.  Unit comes with Basic. 
	Software costs are $30 to $50 per ROM Pac, $18 per cassette,
	?? per disk.  Very reasonable.

Comments:

Wins:  Superb graphics & video game hardware/software.  Much of this
is hidden gold -- that is, Atari doesn't tell you about it.  Atari
promises to fix this. 

Crocks: No access to processor bus.  All expansion via 15pin high
speed serial ports (19.2Kb) including Disk drives, etc.  You cannot
access more than one device simulataiously, i.e. disk drives and
rs-232 port at the same time.  Oh well. 

			PALEVICH@NBS-10, Dec. 31, 1980

Node: Compucolor II,  Previous: Atari 400/800,  Up: Top,  Next: H89

Users: Cory.cc-06@Berkeley
CPU: 	8080
Memory: 8K RAM, expensive upgrades.
Display: Fairly nice 128x128 graphics (although the colors only have
	a 64x32 resolution).  There is no lowercase.  That part of the
	character set is taken up by a set of singularly useless
	graphics characters.  It is very easy to get into graphics
	mode from basic, which really confuses the screen. The
	graphics has some nice vector modes, but a gratuitously bad
	choice of graphics characters makes some of them work very
	strangely. 
Keyboard: a detached keyboard.
Mass Storage: A built-in disk drive.
Operating System: Basic in ROM, with a File Control System (FCS) and a
	Graphics/CRT Subsystem. The BASIC is fairly complete, lacking
	in particular the string function 'instr' and others of the
	kind. Also irritatingly lacking are defined functions of more
	than one argument. The commenting allows you to leave blank
	lines in your program, even though it has a standard BASIC
	editor. The BASIC uses extensive tokenisation to save memory.
	It is possible to execute FCS commands from basic through an
	escape sequence. It is also possible to do this in terminal
	mode.
	The file control system, which is required to do anything,
	uses a particularly bad system of indexed files with no method
	of changing the size of a file except by making a copy of it.
	No sequential files in the ordinary sense at all. No way of
	accessing anything but a random access indexed file from
	basic. This means no fiddling with basic source (or repairing
	it after a disc crash). When deleting a file, the FCS ALWAYS
	COMPACTS THE DISK. It uses screen memory for temporary
	storage, and if you have any bad cells in this area (as the
	machine I use has) then deleting files is VERY hazardous. It
	is not interfacable with anything. This means you can't use
	CP/M even if you have the memory.  Assembly language programs
	(if you have the assembler) are fairly chancy. There is no
	monitor in the ordinary sense, though I have a program to do
	much of the work of one. To do any keyboard/screen I/O you
	have to do all scrolling, etcetera yourself, as they don't
	tell you the entry points to the Graphics/CRT Subsystem.

Comments:

The machine is basically locked into BASIC, and if you want anything
else you have to pay for it. 

Hitting '^A' will attempt to load a program named 'MENU' from the disk
and run it. Can be VERY bad.  

Backspace is ^Z, home is ^H, delete is ignored, and interrupt is
LINE-FEED!!! This means to use the terminal mode is VERY difficult.  

It is possibly to make it explode either by hitting CPU RESET too
often and fast or by doing an 'OUT [1-6],anything' from basic. I am
not joking. The screen disappears, there are loud noises, smoke comes
out, and you have to replace chips. 

The disk drive is right next to the screen, so if you leave a diskette
in it is likely to become randomised, and when you are loading or
saving the screen flickers badly. The compucolor diskettes are
terribly thin, and so you can only use one side of them. Better to get
someone elses disks. 

The disk format is totally incompatible with everything. The drive
can't be rewired to work with anything. 

	 			Cory.cc-06@Berkeley, Feb. 14,1981


Node: H89,   Previous: Compucolor II,  Up: Top,  Next: Micro Chroma 68

	Heathkit H89 (also known as Zenith Data Systems Z-89)

Users: JJD@MIT-MC, RossJ@Rand-Unix
Price: Kit form $1695, built $2800
CPU: Z-80 at 2.048mHz
Memory: 16K RAM (4116's) standard. Expandable to 48K by just plugging
	in chips, to 64K with extra hardware (~$50).
Display: Based on the H19 Ascii  terminal.  Terminal has its own Z-80
	for smart terminal functions including Insert Line, Delete
	Line, Insert Character, Delete Character, Clear to End of
	page, Clear page, Clear to End of line, many others.   See
	INFO TERMS  entry for H19.  Fully supported by ITS via CRTSTY
	and TCTYP +%TOLID and TOPS-20 via TERMINAL HEATH.  Works great
	with EMACS. (even at 300 baud!).  Full 12" B+W screen with P39
	white phosphor.   Thirty three graphics characters are
	available in addition to the full upper and lowercase ascii
	set.  Character reverse video is provided. 
Keyboard: Full ascii keyboard with 8 function keys and keypad.
I/O Ports: RS232 serial port is $100, allows you to interface
	processor to printers and other computers. Although it is
	possible to use the H89 as a terminal without purchasing this
	interface by buying an RS232 connector plug.  Of course in
	this way, downline loading is impossible. 
Mass Storage: One 5" mini floppy (single sided, single density, 102K
	per disk formatted) is standard.  Dual 8" floppies are
	available for over 2Meg of storage.  Cassette interface is
	supplied with the kit.
Operating System: HDOS ($150), which I consider to be a good operating
	system compared to CP/M.  Included with HDOS is an 8080
	assembler and a version of Dartmouth BASIC (not very good). 
	CP/M (*note CP/M: CP/M.) is also available for $150 but
	requires a ROM for $55.  This is needed because the monitor is
	ORG 0 and so is CP/M.
Software: Business software, wordprocessing software, COBOL, FORTRAN
	and Microsoft Basic are available under both operating
	systems. Walt Bilofsky (Walt@Rand-Unix) has a full screen
	editor, a C compiler and a LISP interpreter for very
	reasonable prices.  These run under HDOS. 
Users' groups: The Heath Users Group (HUG) publishes a bimonthly
	newsletter and has a large sofware library available to users
	at low prices. 

Comments:

The kit is easy to build, all of the logic boards are prewired.
Approximate assembly time is 24 hours. 

I don't think this  is a very good  machine for hardware  hackers
because I haven't seen much data  on the bus or the internals  of
the machine.  However, I don't think  it can be beat in terms  of
usability, power,  and  convience.  I  don't  know of  any  other
"packaged" system which uses an ascii keyboard or has an 80 x  24
display.  I am very  pleased with it.   The only real  misfeature
that I know of is that is has a loud fan.

				JJD@MIT-MC, Dec 7,1980

I found the kit easy to assemble. I had a faulty disc drive (Siemens),
but Heath replaced in gratis under the warranty. I use Walt Bilowsky's
software (reach, PIE, C/80), which is excellent, and bought a few
things from HUG (not so great). I run HDOS. I am an amateur, not an
experienced programmer, but I give the H89 high marks. My only
complaint is the very noisy fan; I replaced it with a quieter Roton.
The H89 does need 2 disc drives to be efficient, and I plan to get
the Heath add-on drive soon. 

			 RossJ@Rand-Unix, Dec 18,1980

Node: Micro Chroma 68,   Previous: H89,  Up: Top,   Next: Osborne 1

Users: FEINBERG@CMU-20C
Manufacturer: Motorola.  Distributor is Austin Electronics in 
	Austin, Texas.
Type of System: Single board computer which connects to the
	Exorsizer bus.
Price: The partial kit, which includes all LSI chips, a manual and a
	double-sided PC board costs a mere $200.  Or you can get the
	whole deal.
CPU: 6808 (which is just a 6800 with an on chip clock)
Display: It has a 6847 color generator chip and a video modulator
	chip.  The generators is very versatile and can generate up to
	eight different colors in low-res mode, and 192x256 graphics
	in high-res mode (background and one color only in high-res
	mode).  The chip also supplies a 32x16 character display which
	the TVBUG monitor uses to communicate with you.
Keyboard: You must supply a standard ascii keyboard. Note though, you
	must tie the unused cursor position lines down if you don't
	have the suggested microswitch keyboard or equivalent.
I/O Ports: Included are a 6821 PIA and a 6850 ACIA.  The ACIA is used
	as part of the Kansas City Standard onboard cassette interface
	(at 300 baud) and the PIA is used to connect a keyboard to the
	system. 
Operating System: The system includes a 6846 ROM/IO/TIMER with a TVBUG
	monitor.  The TVBUG is reasonably smart and allows you to
	enter and debug machine code, and load and save from cassette
	tape. 
Add-ons: There is a kludge space on the bottom of the board for
	drivers for the EXORsizer bus or for whatever you want.

Comments: A good board for the money.

				FEINBERG@CMU-20C, Feb. 8, 1981

Node: Osborne 1,   Previous: Micro Chroma 68,   Up: Top,    Next: OSI

I got a look at this beast yesterday at the West Coast Computer Faire,
and it really is sort of interesting.  From their "hardware at a
glance" comes the following:

Standard Hardware 
  o  Z80A
  o  64K RAM (60 available to programmer)
  o  2 Floppies w/ 102k each
  o  Full "business" keyboard    ("italics" mine -- a fair keyboard)
  o  5" monitor.  52 by 24 memory mapped screen.  Automatically
     scrolls horizontally across a 128 character line.
  o  IEEE/488 interface
  o  RS232C interface
  o  Seperate modem interface (modem w/ coupler available Q3 81)
  o  External battery pack connector (pack for 5 hrs available Q3 81)

Standard Software
  o  CP/M (*note CP/M: CP/M.)
  o  WordStar with MailMerge
  o  SuperCalc
  o  CBasic and MBasic

All this for $1795.  It also looks as if you really can fit it under a
plane seat without owning the plane.  Might be a kick to get through
airport security, though.

A few notes: The keyboard is "fairly" standard, and not too unpleasant
to the touch.  The monitor is *small*, and, if the information on the
screen is dense, very hard to read.  The floppies seem to be mounted
in a way that would protect them from being bashed if one were to drop
the case (look out, american tourister).  Space is also provided below
each floppy for diskette storage.

Their sales pitch seemed geared to the travelling engineer.  Also, the
models on display looked slighly different from the pictures in their
literature.  The said that they're demoing "experimental" models.

Time will tell.
     			DWS@LLL-MFE, 4 Apr 1981


Node: OSI,     Previous: Osborne 1,    Up: Top,     Next: PDP-11/23

	OSI C2-4P, C2-8P, C4P, C8P, C1P & Superboard (SBII)

General: The C2-4P is 15"x18"x4.5".  The general appearance is similar
	to the SOL-20, but it doesn't have the stained wood sides.  It
	is discontinued, but is still available retailly. The C2-8P is
	17"x15"x10". It resembles pictures of the SWTP 6800 system.
	All jacks are on the back panel and the front panel has a
	shiny silver panel on a blue background.  It has a MONSTER of
	a power supply.  The C4 and C8 are OSI's new versions of the
	C2-4P and C2-8P. The SBII is a single board computer, just
	plug in a CRT and +5 volts and you're up.  The C1P is the SBII
	with a case and power supply.
Prices: C2-4P is $500 with mini-floppies $600 extra. C2-8P is $700
	plus $1000 for 8" floppies.  C4 is $700, $1700 with
	minifloppies, and the C8 is $900, $2600 with 8" floppies (2).
	The SBII is $280, C1P is $400, $1000 with 20K RAM and 5.25"
	disk drive.
Bus: 	The OSI C2, C4 & C8 all use OSI's 48 pin bus. This is an
	extremely noise free bus, but has drawbacks that should be
	noted. It is not S100 and in the C2-4P and C4P, there is only
	a 4 slot backplane, and two slots are used in the basic
	configuration. The C2-8P has 8 backplane slots.  OSI supplies
	numerous boards for the 48 pin bus, notable are the Votrax (R)
	unit, the universal telephone interface <phone-phreaks
	ultimate!>, AC remote control, home security system, and many
	static & dynamic memory boards.
CPU: 	The C1, C2s, C4 & C8 are controled by a 6502 micro-processor.
	Therefore, they cannot run CP/M 8080, Z80, or 6800 code; but
	this is no drawback for there are millions of programs written
	in 6502 code.
Ports:  Three RCA phono jacks on the rear panel take care of the video
	out <yes, RCA jack, Virginia>, tape in, tape out.  I have
	changed these jacks on my computer to BNC, and phone,
	respectively. For the video interface, simply connect the RCA
	jack to the input of any CRT monitor.  If you prefer to avoid
	that expense, use any low cost RF modulator to hook it up to
	your TV set's antenna terminals.  The floppies for the C4 and
	C8 have extended ports (e.g. RTC, home security, DA/AD
	converters and much more.)
Display: C1 and SBII have a 24x24 screen. The C2, C4 and C8 have a
	64x27 screen, (software selectable 32x27).  The C4 and C8 have
	color graphics (the others are Black&White).
Keyboard: The C2-4P has a self contained keyboard which is a dream to
	operate.  It is a real typewriter style keyboard with
	capacitive contacts and the "feel" to a touch typist is almost
	indistinguishable from an office typewriter. The C2-8P has a
	detached keyboard.
Mass Storage: The C2-4P and C4 are available with minifloppies and
	the C2-8P and C8 with 8" floppies.  OSI produces only
	mini-floppy upgrades for the C2-4P and C2, and only 8" floppy
	upgrades for the C2-8P and C8.  This is no problem though, all
	one needs to do is order whichever upgrade he wants, and
	simply plug it in himself.  The 630 board is available for
	adding disk(s) to the SBII.  The C1P is available with 5.25"
	floppies.
Operating System: All the computers support Microsoft 8k basic <made
	by the same people that designed Applesoft, RS L2, PET, and I
	believe Atari basics> in ROM.  There is also a system
	mini-monitor.  On power-up, the screen displays "D/C/W/M"; D
	stands for "disk boot"; C stands for "Coldstart ROM Basic"; W
	for warmstart <either disk or ROM basic>; and M is for
	monitor.
Software: OSI has a large line of educational, business, personal and
	game programs, and Aardvark Electronics has a large catalog
	devoted to OSI hard/software; also Kilobaud magazine has
	started publishing many OSI articals lately. OSI's public
	relations have improved greatly too. Problems in finding
	support for OSI computers is definitly a thing of the past. 

					PST@MIT-DM, Jan 15, 1981

Node: PDP-11/23,   Previous: OSI,   Up: Top,   Next: SD Systems Z-80

		 PDP-11/23 running RSTS/E

Users: LLOYD@MIT-AI

Basic system: 

The hardware configuration I run is:
        PDP-11/23 processor
        BA-11N box with 9 x 4 backplane (9 usable Q-bus slots)
        256 Kb of DEC RAM (4 x MSV-11-DD)
        Bootstrap/Diagnostic ROM with RT clock (BDV-11)
        4 serial ports (DLV-11-J)
All of the above is the PDP-11/23-AC from DEC.

Price:

IT AIN'T CHEAP!  The CPU was aquired from an OEM who needed bucks in a
hurry.  He let us have the CPU for $6,500.  The disk/tape subsystem is
$9,900.  No, it's not your basic home computer, but it might be of
interest to those of you building big business-microcomputer systems.
A RSTS/E license only (no documentation, media, binaries; nothing but
the right to run RSTS/E on your machine) runs about $8,000.  If you
want full DEC support, it will set you back a mere $17,000.
Basic-Plus-II license only is about $3,000 and a Datatrieve license
only is about $2,000.  My approach was to get a license only, then
spunge off of another RSTS/E site to get up and running.  Much
cheaper. 

Mass Storage:

I have a United States Design Corp. winchester disk subsystem.
It consists of:
        20 Mb IMI-7720 disk drive
        DEI cartridge tape unit
        power supply and box to match the DEC styling.

The cartridge tape is the beauty of the whole system.  As far as the
OS is concerned, the tape is another disk.  The disk is addressed as
DK0: and the tape is addressed as DK6:.  ALL disk operations
(including random seek and block overwrite) are available on the tape.
[-- USDC (Crofton, MD) is considering offering their disk subsystem
for other uP systems (I think).  If you would like to have something
like it for another uP, give USDC a call and let them know. --] DEC
machines can either be a hardware hacker's delight or a turnkey (no, I
din't mean TURKEY) dream.  DEC spends lots of green documenting their
hardware well.  USDC is much smaller, but their documentation is
fair-to-good.  Since the disk subsystem comes ready to plug in (with a
bootable RT-11 V3.2 on a tape cartridge), there should be no problem
other than plugging the interface bd. into the backplane.

My disk system was DOA, but a new set of firmware ROMs in the
controller cured the problem.  USDC assures me that their QC is much
improved, and infant mortality is about an order-of-magnitude lower
now (also my disk was a production prototype).

Operating System:

If you use standard DEC disk subsystems (RL01, RL02), or a DEC
compatable disk subsystem, RSTS/E will run on the 11/23 with NO
MODIFICATIONS (you do have to have the real-time clock though).  The
USDC disk subsystem required a custom driver for RSTS/E.  USDC offers
RT-11, RSX-11M, and UNIX drivers for their disk.

Let me now talk of the RSTS/E OS and the software available for it.
RSTS/E stands for Resource Sharing Time Sharing / Extended.  It can
support up to 64 tasks and up to 128 asynchronous ports.  It can run
with as little as 128Kb RAM, but it is best with 256Kb.  On the 11/23
I feel that 6 simultanious users is a comfortable maximum allowing
reasonable (under 1 second) response time for most activities.  The
big advantage of RSTS is the abundance of existing application
software.  There is more software for RSTS systems than for any other
OS I know of (IBM excepted).
RSTS is also the easiest-to-use and most friendly operating system I
have ever dealt with.  It is also fairly capable.  Last year I
implimented a store-and-forward message switching system supporting
512 nodes.  I wrote the package (at the client's demand) in BP2.  It
can be done but I don't recommend it.

Software:

RSTS comes bundled with all utilities (assembler, linker, file and
user-account maintainence programs), a record management facility
(sequential, random-access, and B-tree organized ISAM filestructures),
and a VERY powerful shared-code BASIC interpreter that beats the pants
off of anything Microsoft makes.

RSTS/E BASIC, called Basic-Plus, provides most language features we
have come to expect from a programming language.  In Basic-Plus (BP)
you will find full arithmetic, string, and matrix functions;
print using; 
IF...THEN...ELSE; FOR...UNTIL; FOR...WHILE; WHILE...; UNTIL...; 
<expression> IF <condition>;
<expression> UNLESS <condition>; multi-line DEFs; string arithmetic,
core common (for chaining); chain to line XXX of another program;
integer, single-precision, and double-precision variables; long
variable names (all characters significant); multi-statement lines;
multi-line statements; etc.  If you have ever seen a basic feature, BP
probably has it too.

As for speed, BP is pretty fast.  In recent benchmarks between
Microsoft BASIC on an 8086 and BP under RSTS/E on an 11/23, BP was
from 4 to 15 times faster.  This was just comparing core-only jobs (no
disk I/O tested) in a single user environment.

If you like Basic-Plus, DEC has also come out with Basic-Plus-II
(BP2).  BP2 is a true compiled basic.  It has all the features of BP.
In addition it supports external subroutines (BP2 or MACRO-11
assembler), and direct use of RMS-11 file structures.  Being a
compiled language it exhibits the usual speed increase over an
interpreter (typically 5 times over BP).  If the task is too large to
fit into core, BP2 allows you to build overlays.  It is possible to
fit a 600+Kb program into the 64Kb addressing range of the PDP-11
using overlays.

Of course RSTS/E supports the major languages too.  From DEC you can
get Fortrash, COBOL, DIBOL (DIgital's Business Oriented Language),
APL, and RPG-II (Rotten Programming Garbage).  Several vendors offer
'C' and Pascal.

Another software goodie is a very nice Database query/report generator
called Datatrieve.  Datatrieve uses an English-like syntax that is
very easy to use.  For example: if I have defined a domain called
"Hackers" containing all the names of people on mailing lists and what
lists they are on, I could query this by saying, "Find all hackers
with mailing.list containing INFO-MICRO or HUMAN-NETS" would result in
Datatrieve responding, "<N> records found." I could then tell it to
sort the collection on any field and print a report by saying
something like, "Sort Current collection on Mailing.list, last.name,
first.name.  Print First.name, last.name, mailing.list of current."
Not AI, but not too shabby either.  BTW, Datatrieve can operate on any
RMS-11 files including those generated by a BP2 program.

Comments: 

If anyone has any questions on RSTS/E, the PDP-11/23, or applications
under RSTS, drop me a note (LLOYD at MIT-AI).

					LLOYD@AI, Dec. 10, 1980

Node: SD Systems Z-80, Previous: PDP-11/23, Up:Top, Next: Sinclair ZX80

		The SD Systems Z-80 Starter Kit

Users: 	LINN@BBNE
Type of System: Single card
Target Users: Clearly, also, this is a machine for hardware twiddlers,
	though I could also see it as being a good general
	introduction to the micro-world. 
Price: Around $300, depending on whether you buy the kit or the
	assembled version. 
CPU:	Z-80
Memory: There is 1K worth of 2102s included, plus board positions to
	add another K.  There is a socket and ROM software to program
	2716s, and an extra socket to put in a 2716 that you program.
Display: Hex numeric led display.
Keyboard: Hex key pad.
I/O Ports: Z80 PIO (both sections available) and a Z80 CTC (one
	section available).  The ROM also provides a (painfully slow
	-- 300 baud and two bytes per character) Kansas City/Intel Hex
	Cassette interface, which works fine if and only if your
	machine has good speed accuracy (the read routines don't adapt
	to tape speed). 
Add-ons: I don't believe there is much available designated as an
	option for this machine, but there is a fairly sizable
	wire-wrap expansion area and two "almost" S-100 sockets. Among
	other attributes, the data in and data out lines are wired
	together (making, in effect, a bidirectional bus). This causes
	no problems to some cards (for example, I am using an Ithaca
	Audio 8K static card with no hassles); any card that might
	have its outputs enabled while the CPU is writing output data
	would have trouble.  There is also no provision for wait state
	control, and some of the S-100 control lines are "replaced"
	with approximate z-80 equivalents. Drive is limited by the
	capacity of the CPU chip itself.  As must be clear, this is
	not an infinitely extensible configuration, but it is well
	thought-out for what it tries to do.

Comments: 

Altogether, I like it as a basis to put together a standalone
machine; I am currently running it as a terminal with a homebuilt
24x80 memory-mapped video board.

The only problems I've had have come from intermittent contacts on
the keypad and in IC sockets. Also, the aforementioned criticism of
the speed and finickiness of the cassette interface.  Consideration
is necessary before deciding whether a given S-100 device can or
can't be plugged into one of the sockets. This might be a good
choice for someone trying to build a ROM-based FORTH machine or the
like; there is room for several added PROMs in the wire wrap
expansion area.
				LINN@BBNE, Dec. 18,1980

Node: Sinclair ZX80, Previous: SD Systems Z-80, Up:Top, Next: Sorcerer

The Sinclair ZX80 comes in two forms, assembled as the ZX80, or in kit
form as the MicroAce. These are the same beast on the inside.

Primary Language - 4K Integer Basic; version developed by Sinclair is
		   not compatible with any other version but is rather
		   powerful.  An 8K floating point Basic is promised.
Memory Size      - Maximum RAM is 2K, ROM on board is 4K.
CPU		 - Z80
Expandability    - Excellent. Most of the z80 pins are brought out to
		   an expansion connector. (Look what Radio Shack did
		   with that in TRS-80 model I (*note TRS:TRS80 I.))
		   Reportedly in the plans are a low-cost printer,
		   memory expansion, and a fully automated tape
		   transport. 
Input            - A membrane type keyboard that should be replaced 
		   immediately and cassette.  All of the BASIC
		   keywords require only one keystroke to type.
Output           - Video Display 32 chars on 24 lines. The TV output
		   is black on white, but adding a jumper makes it
		   white on black.
		   Built in RF modulator to Channel 34.
		   Cassette.
Peripherals      - None
Cost             - $149-200 depending on options and if kit or
		   assembled 

The Basic is fairly powerful as a Basic although it does have some
severe limitations. Capabilities include any length strings in 26 vars
(A$-Z$) any length one dimensional arrays in 26 vars(A(n)-Z(n)) and
any number of Integer variables with any length names (ie
ADDRESSOFAFRIENDOFMINE is valid, and all characters are significant).
Warning: when using strings this BASIC is SLOW.

Functions in the Basic include a random number generator, a CHR$(n)
function for printing characters of value n, Code (n$) for getting the
numeric equivalent of the leftmost character in string n, TL$(n) for
stripping off the leftmost character of string n, and PEEK. There is
no concatenation function at all. The editor in this machine is no
EMACS but it is quite usable.

Also Machine programming is through Pokes and a call to USR(Address).
Unfortunately USR does not allow one to pass variables, only call to a
specified address. Also there is no DATA/READ construct so entering
machine code is tough. The Z80 on board is worked to the maximum
capability, (The cassette interface is about 6 components) but it does
do everything admirably.  Yet when it does something other than
display the screen, that is read a key from the keyboard or run a
program or read/write a cassette, it loses sync and/or the entire
display, depending on the function, which causes very annoying jumps
in the display on type-in and difficult interaction in programs.

Recommendations : 

It is a fun little system and good for learning on, it is reasonably
priced and easy to assemble in kit form (the traces are quite close
though).  The membrane keyboard in my kit I replaced by an old Radio
Shack keyboard and cut up the old membrane stuff, which is adhesive,
and made keycaps.  The entire matrix can be brought out to a 16 pin
dip connector. Get the 2K kit since the extra ram is very useful on
any program, and get the Book on the insides for 12.50 if you are at
all interested in making a larger system out of it.

Any other questions send them to MCMANIS@USC-ECLB-IPI
			         16 Mar 1981



Node: Sorcerer,   Previous: Sinclair ZX80,  Up: Top,  Next: Superbrain

		    Exidy Sorcerer I and II

Users: SAM@MIT-AI, TANG@MIT-AI, INFO-EXIDY@MIT-MC
Manufacturer: Exidy
Target Users: [SAM: The system requres about the same expertise as the
	popular consumer computers.  Sorcerer owners tend to believe
	they have a better growth potential.  Frustration is minimized
	by a highly reliable cassette interface,and the high quality
	video and keyboard] [TANG: Expertise needed to use - novice.
	Expertise needed to expand unit - S-100 experience.  The basic
	unit is designed for the Hobbyist, ala TRS-80.  The expanded
	unit is designed for Business, i.e. S-100]
Prices:	Since the machines future is so uncertain prices are
	fluctuating. The Standard Basic with 16K ram is about $1000.
	[SAM: I have seen "liquidation" sales offering the (I) for
	under $400 with 8k.  I recall the list price of the (I) being
	$895 with 8k and the S-100 unit being $350 but I bought mine a
	while ago]. 
	You'll also need a TV monitor for about $200 and a cassette
	player (say Sony TCT-757) for about $70. 
Bus: 	This machine is self contained and as such has only expansion
	"buses". One type is for adding additional Rom cartridges, the
	other is for adding an S-100 adapter.
CPU:  	Z-80 at 2.16 Mhz
Memory: Model I Sorcerers can have 8-32K of RAM and 16K of ROM.
	Model II Sorcerers can have 16-48K of RAM but only 8K of ROM.
	The Sorcerer has a feature of the Rom Pacs - user can insert
	4-8K of ROM, allowing easy switching between Basic, Word
	Processor and Assembler.  All three ROM Pacs are 8K. None of
	them interfaces with Disk.
Display: 64x30 video display which includes upper and lower case with
	descenders. A high quality video monitor is required (on the
	order of a Sanyo VM3209).  A cable for a monitor is provided.
	The display has a character set of 256, 128 of which are in
	ROM, and this includes a complete ASCII set, and the other 128
	are in RAM (programmable). So you can whip up APL and Kata
	kana fonts for your favority special applications, as well as
	little men and women for your games. On powerup, the monitor
	loads this with an extensive graphics set.  The character cell
	is 8x8. So 128 characters is 1K.  There is 2K of memory for
	the screen.  Both are memory mapped. There is no bank
	switching hardware in the machine for any of the contained
	memory.
Keyboard: A high quality full size keyboard with a numeric pad. The
	keyboard is encoded by software scanning.
I/O Ports: It comes with a serial RS-232 port, a parallel port.
Peripherals: The S-100 expansion box ($300) gives you six S-100 slots
	to do with as you wish.
Mass Storage: A 300/1200 baud cassette interface (which shares the
	serial port) is included and a cable is provided for a
	cassette player.  Exidy also supplies a Video/Disk unit which
	is a video monitor combined with dual Micropolis drives ($2000
	with CP/M). Vista makes an add-on floppy unit ($1000) that
	will plug directly into the bus, or (a different model) into
	the s-100 bus.
Operating System: You get a 4K monitor in ROM.
	If you buy the dual drives, you get CP/M *note CP/M: CP/M.
Software: An 8K Microsoft Basic in a ROM cartridge is included in the
	price. There is a Word Processor Rom Pac for $200, a Z-80
	Assembler/Editor pac for $100.  Also there is a cartridge for
	user supplied eproms (2716 type).  Contact INFO-EXIDY@MC for
	more details.

Comments: 

Unit gets very hot. 

80% of all Sorcerers are sold overseas.  Probably because it makes a
very good alternative to the TRS-80 (and Radio Shack has very few
stores overseas).  Australians in particular own Sorcerers.

The computer makes a good terminal, by the way, and there are several
good terminal emulation programs written for it.  

You can't use DMA boards with the S-100 interface.

The best cassette recorder for the sorcerer seems to be the Sony
TCT-757 (or whatever the cheapest Sony recorder is named).

					TANG@MIT-AI 01/09/81


The machine was ahead of its time when it was introduced three years
ago.  My personal bias is that it was poorly marketed.  I would have
liked to see hardware keyboard encoding,  and a 24x80 screen format.
The supplied software (Monitor Rom) is workable but could stand much
improvement.  The hardware itself tends to be reliable.

Caution:  Exidy's future plans are uncertain and the machine may be
discontinued!! 

The documentation supplied is reasonable and one would probably want
to purchase the technical manual (schematics) and the software
technical manual (Monitor Source)

				SAM@MIT-AI,  01/10/81

Node: Superbrain,   Previous: Sorcerer,   Up: Top,   Next: Sym-1

Users: PLK@MIT-MC
Manufacturer: Intertec Data Systems, 2300 Broad River Road,
	      Columbia, SC 29210. Telephone: (803) 798-9100. 
System Type: Video, keyboard, CPU board and drives all in one unit.
Price: The basic configuration is $2500
Bus:   The bus is of their own design, needless to say it provides
       all the Z80 stuff (A0- D0-D7, BUSACK, K, BUSRQ, RD, WR etc.).
       You can get an S-100 bus adaptor for about $300 extra.
CPU: 	Z80, 4 Mhz
Memory: 32K RAM in basic system, can go up to 64K (about $50 do it
	yourself) 
Display: 80x24 video display.  Absolute cursor addressing, 4-way
	cursor motion, home, clear to end of line, clear to end of
	screen.  No lower-case descenders.  Very crisp, clean video.
Keyboard: separate numeric keypad, 4-way cursor motion keys.
I/O Ports: 2 RS232C ports (to 9600 baud) come with the unit. A
	parallel printer port is available for about $100 extra.
Mass Storage: Comes with dual double density 5" floppies with 320K
	capacity, controlled by a separate Z80.
       Intertec has just announced a hard disk (10 M) system which
       uses the Z80 bus (approx $2500).
Operating System: CP/M 2.2 *note CP/M: CP/M. Thus all the software
	that runs under CP/M is available commercially from Lifeboat,
	etc.  Users' group (CPMUG and SIG/M) software is also
	available, however, the non-standard disk size and file size
	(512) means modem file transfer will likely be necessary
	unless you can make contact with other Superbrain users.
	There is a variant operating system called SUPER-IOS available
	from Systems Integration, 1623 Third Ave., NY, NY 10028, (212)
	831-5229 for $175.  It is CP/M compatible, apparently designed
	specifically for the Superbrain, and has many nice feature
	(according to their literature).
Users group: SuperBrain Users Group, 420 French Court,
      Menlo Park, CA, 94025.
      There is also a newsletter: Supperletter, P.O. Box 3121,
      Beverly Hills, CA 90212.

Comments:

Misfeatures:
1) There's no documentation on hardware, port addresses, screen
location in RAM, software baud rate setting, software reversing of
video, etc 
2) Generation of ctrl-W impossible even with direct keyboard input
routine (06) in BIOS. This undocumented misfeature has the following
effect: ctrl-@ is displayed and video (not printer) is turned off when
carriage return is entered. Repeating the operation, i.e. ctrl-W
followed by carriage return, turns on the display again. This probably
has to do with entering passwords etc. Since I wanted to use MINCE
(Mark of the Unicorn), a variant of EMACS for CP/M, I needed ctrl-W to
write a file etc. The misfeature was eliminated in my 64K BIOS by
replacing the code at E517H to E51BH by NOPs.    
3) Very little help from manufacturer.

Getting this machine to do anything unusual has been an adventure. For
$50 one can get hardware information which consists of a set of
circuit diagrams. Using the assembly language version of the portion
of the BIOS provided and the CPU circuit diagram one can figure out
how it all works, but what a chore. For instance, one has to search
through the BIOS to find out how the baud rates are set and what the
addresses of the RS232C ports are. After these are found then one can
write a terminal emulator (eg. VT52). To attach a parallel printer we
had to build our own interface as the manufacturer was way behind the
date he promised for delivery in his advertising. Reverse video and
other goodies can only be done by looking at the circuit diagram and
understanding how various chips function. If one wants an education in
micro hardware then here is an oportunity.  Speaking to a "tech"
person a Intertec got me nowhere. For example, he told me the ctrl-W
misfeature bothered others but had no suggestions for solving the
problem.  He did say that they were planning to produce a technical
manual sometime during the Spring of 81.

I have heard from several people that there have been disk reliablity
problems. So far, I have had none.

     					PLK@MIT-MC, 02/09/81

Node: Sym-1,    Previous: Superbrain,   Up: Top,    Next: SWTP 680X

Users:  GNU@AI is building a chord keyboard (IEEE Computer, December
	78) using one.
Manufacturer: Synertek Systems Corp, 150 S. Wolfe Rd, Sunnyvale CA 94086
	(408) 988-5600.  Stocked at many computer stores.
Type of System: Single-card.
Target users: Hacker, Student.  Good for prototyping or one-shot
       deals. Makes a good flexible controller.
Price:  About $250 gets you the base system, which has sockets for the
	extras. 
Bus:    KIM/SYM/AIM bus.
CPU:    6502, 1 Mhz clock.
Memory: 1K static RAM, with sockets and decoding for 4K (2114's) 128
	bytes of RAM in a SY6532, used by the monitor.  4K ROM with
	monitor, sockets for 3 other ROM/PROM/EPROMs; you can replace
	the monitor or any of the others with a 2716, 2316, 2332, or
	2364, up to a total of 24K E/P/ROMs onboard. You can also
	select which of the 4 sockets gets ghosted to high memory at
	power-on.
Display: 6-character 7-segment LED, plus power and audio LED's.  Comes
	with an RS-232 port, and the monitor is designed to use it.
	Also has a current-loop interface, ditto.  It does autospeed
	(up to 4800 baud) for the RS232 port.
        You can also attach an oscilloscope to a particular output pin
	and using supplied hardware and software (listing), display up
	to 32 characters on it.  The driver routine outputs a sync
	pulse and the characters in 5x7 dot matrix form every 50 ms
	while doing keyboard input.  This was for the electronix type
	who had the scope but was stuck with the LED display.
	The monitor makes good use of the 7 segments and associated
	"decimal point" spots for hex and some letters -- much better
	than the KIM did.  You drive it in ASCII, the monitor
	converts.  Note that since the display is scanned in software,
	it is blank while a program is running (tho a monitor entry is
	provided that will scan it once; if this is called about 50
	times a second, it looks fine.)
Keyboard: 28-key solid-state flat keyboard, including the hex digits,
	Reset, Debug On/Off (NMI after each instruction except in
	monitor), CR, +, -, left and right arrows, Shift.  The rest of
	the keys, and the shifts of the hex keys, are shorthand for
	the monitor's command set.  Included is an ASCII key which
	accepts 2 hex digits and presents the corresponding byte.  The
	monitor and programs deal with the keyboard in ASCII, the
	monitor does the translation.  There's a beeper which beeps
	when a keypress has been read.  The keyboard is scanned in
	software (except Reset, Debug On/Off) and can be redefined by
	software.  A monitor routine is provided to tell if any key is
	currently being pressed (BREAK is used on an RS232 or current
	loop device).  Pressing a key doesn't generate an interrupt,
	so you have to scan if you're interested.  When a terminal is
	in use, it ignores the onboard keypad (exc. R, d n/f).
I/O ports: Comes with 2 SY6522's and a 6532, with all ports brought
	out to one (or more) of the four edge connectors.  A socket
	and edge connections for a third 6522 is provided.  The 6522
	VIA contains two standard 8-bit bidirectional parallel ports,
	with control by bit.  Each parallel port also has 2 control
	lines for handshaking. The 6522 also has two powerful interval
	timers and an 8-bit shift register, which can be intertwined
	in a bewildering variety of ways, and can control or be
	controlled by a subset of the parallel ports and control
	lines.
	The 6532 has 16 bits of PIO, an 8-bit timer, and 128 bytes of
	RAM, which is used by the monitor for its variables, display
	buffer, etc.  Four of the PIO lines are buffered by circuits
	which are designed to be customizable.  Eight of the lines on
	each chip can directly drive transistors (3ma @ 1.5v).
	Note that there are no U/S/ARTs.  Serial I/O is done on the
	PIO ports in software.  The shift register and timers in the
	6522's make it not a hard job; the monitor does it all "by
	hand" though, with delay loops.  This is probably the only
	drawback of the board for my application, which wants to sit
	between a terminal and a modem.
Mass Storage: KIM format and high speed cassette interfaces are
	provided in the monitor for loading and dumping memory.
	On/Off remote control is also supplied and used by the
	monitor.  I suspect most people download over the RS232 if
	they're doing serious work.  I will, from an Apple or Amdahl.
Peripherals: Micro Technology Unlimited has a motherboard/card file,
	16K RAM card, Visible Memory grafix card, and 8-bit DAC card.
	They also supply software for a Music System using one or
	several of the DAC boards.  Any hardware you can attach to a
	KIM will work.  Anything you attach to an AIM will probably
	work, but I'm not sure if AIM conforms exactly to the KIM
	standard bus.
Operating System: Excellent; provides ASCII support so that the rest
	of the software doesn't know if it's running with a terminal
	or with the onboard display and keypad.  A good cheap
	debugging monitor, with about the power of the Apple's but
	without the bugs (and, unfortunately, without the
	mini-assembler and disassembler).  Will read paper tape
	format, and read/write Kim (8 bytes/sec) and high-speed (185
	bytes/sec) cassettes.  Monitor I/O is vectored via that 128
	byte RAM so you can plug in your own routine, and there is a
	command for executing "macros" by reading sequentially from
	memory til it sees a hex 00.  All unrecognized commands are
	vectored, so you can write your own.  Errors are reported with
	the hex value of the char in error, or a few other values for
	cassette checksum errors, etc.  The monitor does not use any
	interrupts except the Debug (NMI after each non-monitor
	instruction). All interrupts are vectored, again thru System
	RAM (in the 6532). A full source listing of the monitor is
	provided, as well as flowcharts and descriptions of the System
	RAM and various tricky routines.
Languages: A ROM assembler and a ROM Basic are available.  Forth,
	monitor and Basic extensions, Tiny Basic, and a 2K assembler
	are available on cassette.
Users Group: Sym-1 Users Group, PO Box 315, Chico, CA 95927.
	Telephone (916) 895-8751. 
	They distribute the Sym-Physis newsletter quarterly at
	$10/yr.  They also provide mail order access to the various
	products mentioned above, books, and others.
Application programs: Moser's Sym Word Processor, various games and
	demo programs, plotting programs, and an EPROM programmer
	control program. 

Comments:

A good machine for a controller.  That seems to be mostly what it was
designed for.  Lots of I/O, reasonable terminal support, ROM and RAM
space, and everything brought out to an edge connector.  It requires
+5V @ 1.5a.  I bought mine secondhand for $150 including all 4K RAM,
and also including a nice plastic case with velcroed cover.  The power
supply fits in the case so it's all nice and neat.

By the time you're done debugging on it, you'll know a good part of
the 6502 opcodes in hex.  Oh well.

GNU 5Mar81

Node: SWTP 680X,   Previous: Sym-1,   Up: Top,   Next: TRS80 I

Users:  Sproul@RUTGERS:
	Mark Sproul, 1368 Noah Rd., North Brunswick, NJ 08902
	(201) 246-3749	
Manufacturer: Southwest Technical Products Corp.
Target user:The FLEX operating system has a very nice user interface
	for the novice and any reasonable assembler programmer can
	hack on it with very little effort.  The hardware is very
	simple to upgrade. Special purpose hardware is very easy to
	build since the bus control signals are very easy (compared to
	the S-100 bus).
Price:  A bare minimum system is $595 assembled and tested, $495 kit.
	This includes a chasis, mother board, CPU, 8K static memory
	and one RS-232 port, expandable to a second.
Bus:	SS-50 (originally developed by Southwest Tech Corp).  This is
	a very popular standardized bus second only to the S-100 bus.
CPU:	6800/6809.  All discussion is geared towards a 6809 system,
	since anyone buying new equipment would want 6809.  The 6800
	is not supported by SWTP since you can get the 6809 now for
	the same price.  (Most other companies still support the 6800
	though, and SWTP still supports the old stuff already sold).
Memory: 8K is included.
Display/Keyboard: You supply your own terminal.
I/O Ports: One RS-232 port is provided (for the terminal).  You can
	expand to two.
Mass Storage: $200 for the minifloppy controller plus 5" drives.  This
	is sold for about $1200 including cabinet, power supply and
	two 5" drives.
	$2495 for dual double sided double density 8" floppies with a
	very good DMA type controller that uses a 1791 disk controller
	chip.  Currently available for $4395 is a 14" Winchester disk
	with its own 6809 on the controller board. Capacity is 16 Meg.
Peripherals etc: There is all the typically required hardware
	available for the 6800/6809 SS-50 bus, including:

	Full function modem - $395.00 from Thomas Instrumentation
	(designed by me) which includes all the necessary software for
	file transfer. 

	Graphics - 256*256 and 512*512 graphics boards.

	Memory - all types of memory avalaible, both static and
	dynamic and one 256K using new 64K chips.
	
	Misc I/O - All types of serial I/O, parellel, clocks, A/D,
	D/A, AC power control, TV digitizer, etc.

Operating System: FLEX by Technical Systems Consultants (TSC) is the
	standard disk operating system to run on 6800 or 6809.  It
	requires 24K of memory (8K for the system, 16K for user) - it
	can run with less, but you can't do much.  It is very easy to
	use for a new user and very nice for a system hacker.  It
	costs $90.
	UniFLEX (Unix + FLEX) is a Unix type operating system for up
	to 16 users on a 6809 system.  It requires 90K memory,
	supports interuser mail, forks, background jobs and a lot of
	other neat stuff.  I plan to have UniFLEX up and running
	sometime in the next year.
Languages: Several different levels of Basic are available and the
	TSC has what they claim (which I believe) fastest Basic for
	the 6809.  UCSD pascal is available and a company in the
	Netherlands has a nice Pascal that I just started using.
	There are two different versions of Lisp available, I have one
	which is about 4K long and very resonable (from what little I
	know about Lisp).  The other is larger and from what I have
	heard better but I dont know anything about it.
Editors & Text Processors:  Several text processors, one modeled after
	NROFF on Unix systems which I use and like.  There are also
	some screen oriented text processors available which I have
	not seen.  TSC supposidly have some screen editors available
	but I have not seen them.  I am writing a EMACS/TVEDIT type
	editor which I hope to be able to release by the end of the
	summer.
Users' groups: There are two (2) magazines JUST for the 680x/SS-50
	users: '68 Micro Journal' and 'SS-50 Computing'.

Comments:

	I consider the SS-50 6800 or 6809 system running FLEX (or
UniFLEX) is a very good system for  the beginner and the advanced
user.  There is no problem with compatibility (I have not come across
any in the 4 years a have been using it).  I highly recomend it to
anyone wanting to buy a microcomputer system.

All of the manufacturers of SS-50 equipment and software houses are
very cooperative.  This was fantastically demonstrated at the 1980
Personal Computing Confrence (PCC) in Philidelphia August 1980 where
there was a large corner of the exhibition floor reserved for just
6800/6809/SS-50 hardware/software vendors. 

			Sproul@RUTGERS, Dec. 11, 1980

Node: TRS80 I,   Previous: SWTP 680X,   Up: Top,   Next: TRS80 II

			TRS-80 Model I

Users:	PLK@MC, MEADER@AI, JMTURN@AI, INFO-TRS80@MC
Manufacturer: Tandy Corp. / Radio Shack
Type:	Distributed,SingleCard
Expertise required: The answer to this from the point of view of
	software is easy. The Basic interpreter can be used by an 8 or
	9 year old. [And it really should only be used by that group.
	It is VERY slow (something like 1/3 the speed of an Apple) and
	you really have to move up to disk before some of the more
	useful BASIC features are available (multiple machine language
	calls, hex and octal notation, and some nice string stuff).
	The Level I is a write-off for anyone >7 -- JMTURN]
	Assembly language programming merely requires knowledge of the
	Z80 instruction set and mapping of the video,
	keyboard, disk FCB, etc. [If you plan to do any serious
	machine hacking, you should get one of the listings of the
	ROM that are available. They're a real timesaver. -- JMTURN]
	What has not been provided by the manufacturer is available by
	purchasing books written expressly for the TRS80 on these
	subjects. Hardware expertise is another question. If one is
	interested in programming, simple modem access to large
	machines (such as MIT-MC), and text processing then at most
	you only need to use a screwdriver. Sophisticated non-standard
	interfaces in a laboratory or industrial environment requires
	lots more work than, for example, using HP micros or a MINC;
	on the other hand, if one has the time ability and fortitude,
	the price is right. To my knowledge no commercial hardware is
	available for auto-dial re-dial operation that one wants for
	PCNET except by going to the S-100 bus with the DCHayes modem. 
For:	Consumer, Small Business
Prices:	$499 Level I Basic 4K RAM
	$849 Level II Basic 16K RAM
	10 to 15% Discounts available
Bus:	TRS-80 Expansion Bus 40 pin
CPU:	Z-80,1.78 Mhz [Hackable to 3.75]
Memory:	4K or 12K ROM Basic
	4K or 16K RAM expandable to 48K total with expansion interface
	($300-$600 depending on amount of RAM included)
	[If you buy your memory from RS, they will charge about $100
        per 16k (they use 4116, 200ns). These can be bought for around
	$30 per 16k elsewhere. Note - Warranty -- JMTURN]
Display: VideoMonitor included, 16x64, Memory mapped. Black & White. 
	Uppercase only, lowercase mod available (for about $59, or $2
	if you do it yourself Note - Warranty)
	Graphics 128 horizontal x 48 vertical
Keyboard: 53 Key, scanned matrix. 12-key keypad with 16K Level II.
	Keyboard is missing full set of control keys available on a
	good terminal.  These must be made-up (e.g. clear = escape)
I/O port: Cassette interface standard, with the expansion interface
	you get a printer port, parallel output, dual cassette. RS-232
	card available ($99).  One can also connect an RS-232
	interface directly to the keyboard, w/o the expansion
	interface. This requires some minor soldering and installation
	of a switch. (Note - Warranty) Estimated time 1/2 hour.
Mass Storage: Cassette recorder included. Disk drives (up to four
	5" single density) $300 each 40 track (expansion interface 
	needed).
Add-ons: As with software, a second source hardware market is fully
	developed for the Model I. There is interfacing for a wide
	variety of printers ($219-$1960), double density disk
	controller modification,allowing 350 Kbytes on one 5" drive,
	RS232C interface directly coupled to keyboard (avoids
	expansion interface), remapper to put RAM at 0000H, speedup to
	4 MHz, Voice ($400) and music ($170) synthesizers, modems
	($200), wide variety of 5" and 8" drives compatable with
	Western Digital controller chip, inexpensive add-on memory
	that is easy to install, a S-100 bus interface, a IEEE-488 bus
	interface and more.
OpSys:	System comes with ROM Basic.  TRSDOS comes with Radio Shack
	disk drives.
	NEWDOS ($135) is a debugged and expanded version of TRSDOS
	from Apparat Inc. It comes with utilities including EDTASM, an
	editor/Z80 Assembler, and a Disk sector editor/patcher. Both
	TRSDOS and NEWDOS come with BASIC. Applications programs will
	generally run on both operating systems.
	Also CP/M is available, modified to run above the ROM (4200H)
	for about $130.  And if one is willing to pay for the extra
	hardware, normal CP/M can also be run. (*Note CP/M: CP/M.)
Languages: BASIC, Tiny PASCAL
	for DOS: Compiled BASIC, FORTRAN, COBOL, Forth, all in the
	 $100-$300 range
Machine language: EDTASM Assembler/debugger. TBUG monitor/debugger.
	for DOS: There are several assemblers, disassemblers and
	debuggers (including one with TRSDOS) available. E.g.
	Microsoft's M80 is available under TRSDOS (it comes
	with Fortran)
Text Processing: Scripsit. For DOS: Electric Pencil.
Communications software: TERM, Mailgram.  Fairly sophisticated
	terminal programs are available (ie emulate a VT50 and do file
	transfer, etc.)
Applications software:	In general, a second-source software market
	for the TRS80 has developed which is comparable only to that
	for the Apple II and CP/M systems.
Users' groups: Many. Also magazines, etc. 80 Microcomputing is a 250
	page monthly devoted to the TRS-80

comments:

Beware of Radio Shack software! Most independent stuff is better.
				-- MEADER@AI

There's no way to use any of Z80's interrupt modes  -- GZ@MIT-MC

From Paul Kelley (PLK at MC):

Model I is apparently no longer in production but at this date
(12/29/80) many dealers still have a good stock. Approximately 300K
Model I units have been sold and used systems should be readily
obtainable. Substantial discounts are available and prospective
purchasers of new machines should carefully scrutinize advertisements
in 80 Microcomputing, BYTE etc.

The bad news is as follows:
    * Unreliability due to connector oxidation.
    * Unreliability due to poor EMI shielding and sensitivity to power
	line surges. (very environment dependent, this is one
	important reason why there is such a wide
	satisfaction-dissatisfaction range among TRS80 users).
    * Poor circuit layout and termination.
    * A poor video monitor on the Model I. Try to buy a Leedex monitor
	($109) or interface a TV (use an opto-isolator circuit).
    * Cassette storage can be trouble; Tandy  fixed most of the early
	problems but cassette I/O is still a slow, painful, unreliable
	process on the Model I.


(JMTURN --
Warranty:
	 Tandy gets REALLY nervous if you open up the machine.
In fact, it voids your warranty. Worse, they won't repair it
even if you pay them... So you have a choice between taking
your chances with your skills, or paying RS's outrageous prices.
On the other hand, there are several computer stores in the
area that service TRS-80s now.)

 My general opinion is that this is a good entry level machine,
particularly if you can find a used system.  Consider the PMC-80, a
Model I equivalent from the Far East.

Node: TRS80 II,   Previous: TRS80 I,   Up: Top,   Next: TRS80 Color

			TRS-80 Model II

Users: INFO-TRS80@MIT-MC
Manufacturer: Tandy/ Radio Shack
General: The entire machine is sturdy, well built, and seems to have
	been designed by someone with experience.  In spite of two of
	ours having been dropped in shipping, both worked fine (once
	we had replaced some connectors which had bounced off).
	The whole thing comes in a single box.
Target Users: An excellent machine for an office or business
	environment.  Not for a hardware hacker (or a system level
	software hacker, unless he likes getting his reference manual
	in the form of a schematic!).  But I recommend them freely to
	customers who wish to COMPUTERISE their business.
Price:	About $3500 from independent distributors for the basic
	package including RS's operating system.
Bus: The TRS-80 bus.
CPU: Z80 
Memory: Memory comes with 32 or 64K, with three slots on the backplane
	available for later boards.  Rumor is mapped memory boards to
	256K, and a multiport serial card for multiterminal support.
Display: 80x24 clear bright display
Keyboard: reasonably good quality keyboard (unlike the Model I), but
	RS has (for reasons unknown) omitted several keys, including
	line-feed, rubout, break.  These can be faked in, but it is
	unfortunate that one has to.
I/O Ports: Two serial ports at up to 9600 baud, and a Centronics
	printer port.
Mass Storage: The main unit comes with a good quality Shugart double
	density disk.  A little noisy but fast and reliable.  Extra
	disks are available up to a total of four.  The expansion
	drive sold by RS is a CDC drive of inferior quality. VISTA
	sells the same expansion unit at a better price with a better
	drive.
Operating System: TRSDOS.  Several people sell CP/M for the Model II
	*note CP/M: CP/M.  I much prefer it to the TRSDOS from RS.  My
	recommendation is for Pickles and Trout CP/M over any of the
	others, especially Lifeboat.

Comments: 

This is a surprisingly nice computer from Radio Shack, in which they
corrected many of the mistakes they made on the model I.

You get local RS service in most cities.

Those neat new cards to plug into the backplane don't exist yet. Nor
is there the availability of 'oddball' cards for laboratory and
science applications (i.e. D/A, A/D, power control, etc.)

The first few machines had a bad bug in the disk controller card.
Worked fine until you plugged in the disk expansion unit.  Then you
got intermittent loss of files on BOTH drives.

			MKNOX@UTEXAS-11, Feb. 11,1981


Node: TRS80 Color,   Previous: TRS80 II,   Up: Top,   Next: HomeBrew

		TRS-80 Color Computer

Users: INFO-TRS80@MIT-MC
Manufacturer: Tandy / Radio Shack
Target users: Right now, it is a fun toy with promise.  Also not a
	bad way to add an intelligent COLOR display to your
	existing system (the machine can be driven at high speed
	through the GAME port).  But I would NOT purchase one for
	serious computing, nor want to use one for a terminal.
Price:	$350 to $400.
CPU: 	MC6809E
Memory: 4K RAM initially (4K by 1 dynamic)
Bus:	The entire system bus is brought out to an edge-card connector
	for Game-ROM insertion.. Pop the game rom and you can insert
	instead an expansion interface, with more memory, floppies...
Display: 6847 color CRTCC. Display is 64 characters by 16 lines, upper
	case only.  Lower case is displayed as the upper case
	character in reverse video.
	Color resolution up to 192x256 (but down to
	forground/background color only at that point).
I/O Ports: There are two 6821 PIA's inside (one for the keyboard, one
	for everything else, including playing software UART for the
	RS-232C)
Keyboard: The keyboard is cheap, but better than it looks.  Another
	keyboard could easily be inserted instead, as the keyboard
	cover and the case are two separate pieces.
Mass Storage: Cassette.  No floppy disk drives, although RS says
	they are on their way.
Other peripherals: Joysticks
Operating System: "Level I" Basic.  The current small BASIC is
	adequate but limited.  It has been extended to allow
	high-level control of most of the features of the system
	(Joysticks, color, built-in speaker, etc.).
Software: Very little. Most of the games out for it are of poor
	quality. And there is as yet no real OS; no assemblers or
	compilers, etc.  Provisions are made in the BASIC for running
	6809 machine code, but little info is provided on this from
	RS. Most notably missing are ROM entry points and addresses of
	the peripheral chips.

Comments: 

This is the color replacement for the Model I (they hope).

The machine is well built, and RFI/TVI shielding is excellent.

The system has been designed to be minimum cost (for example, no
ACIA for the serial port, just a parallel port and fast software
footwork).  However, that is not unreasonable and everything seems
to work.  We got one and immediately opened it up; popped the 4K
RAM and stuck in 4166's for 16K, no problem.

			MKNOX@UTEXAS-11, Feb. 11,1981


Node: HomeBrew,   Previous: TRS80 Color,  Up: Top,   Next: Homebrew-A

This node contains descriptions of various home-brew or otherwise
untypical system, as well as anything else which doesn't fit anywhere
else.

* Menu:

* A:    HomeBrew-A, a general discussion of building/buying an S-100
	system. By LS.BARRY@MIT-EECS [BADOB@MIT-AI].

* B:	HomeBrew-B, a homebrew CPD1802 (RCA's COSMAC), similar to the
	RCA Microboard system.  By AEZ@AI.

* C:	HomeBrew-C, an S-100 based system, Xitan mainframe.
	By PLATTS@WHARTON-10.


Node: HomeBrew-A,  Previous: HomeBrew, Up: HomeBrew,  Next: HomeBrew-B

From: LS.BARRY@MIT-EECS (Barry A. Dobyns, BADOB@MIT-AI), Dec. 14, 1980

  	        S-100 & other addictive habits

I have s-100/z80 frobs & can safely say that nothing is the same
anymore (ever).

Cromemco is a very good board (I have one).  It is NOT IEEE-696
compatible (the cromemco ZPU, not the SBC).  The CCS (California
Computer Systems) is also a very good board, and is IEEE-compatible.
The SSM (solid state music) is about the same as the CCS, but is
harder to build correctly (they offer too many options for the S-100
tyro to figure out) if you come unacquainted with S-100. The SDS is an
OK board, as is the Ithaca Intersystems. the Delta board has some
idiosyncracies best left alone, but otherwise is ok.

You should look for a board that actually has minimum features, (in my
opinion) as features introduce opportunity for idiosyncracies. The 1K
rom space may be a selling point, but you will probably never use it
(you will get a prom-burner board with space for 8K,16K, or 32K.  If
you want proms, you'll need to burn 'em too) and if you can't disable
it, woe betide to you. Or, almost as bad (the Delta is one of these),
you can disable it, but not with a switch, only with software. This
means that you have to hack otherwise normal software; i.e. if you
bought a Morrow floppy controller, and a Delta CPU, the Morrow drivers
have to be modified before you can ever use it. One of the advantages
of the Morrow board is that it can work with nearly any cpu/memory
configuration imaginable, with no modification. The same applies for
serial ports whose addresses are not changable (what happens when the
serial port goes from E0h to E2h and the disk controller goes from E0h
to EFh, and you can't readdress either one???) and other frobs.  If
you can't find out these sort of details beforehand, then forego the
'feature'.  Addressing beyond 64K is a mess in the S-100 world.  There
are at least 3 non IEEE-696 bank select 'standards' none of which are
compatible.  If it's not IEEE-compatible don't even bother with it.
Cromemco ZPU does not have extended addressing circuitry on the cpu
card, it puts it on the memory card(s).

Boxes are not all created equal.  The major differences are in the
quality of the motherboard.  Shielding (preferred) eliminates
crosstalk, termination (active preferred) cuts down in ringing (the
SSM motherboard, a single sided, unshielded unterminated job is
excessively noisy), the heftiness of the power suply (hefty is,
needless to say, better; you never know how many high-current frobs
you will eventually stick in the box, and 22 slots is a lot of space
for frobs).  Some of us still go for front panels (Ithaca Intersystems
is the only one who still make one) since one can do a lot of hardware
debugging from one, and the lights are reassuring when you have
noticed that the compile has been going on for an hour now and you are
worried that the system has hung up on you.  If your box has a line
filter, that's good.  Elevators and washing machines can gronk your
computer (sometimes, only if the phase of the moon is in agreement
with your computer's astrological sign, and the task you are running
is very critical and non-trivial to reproduce) but good. CCS and
Integrand make passable (and $cheap$) boxes.  Godbout makes an
excellent (and $expensive$) box. If you can find an old IMSAI box, and
put a Godbout motherboard in it, you will have (in my humble opinion)
a superior box.  This is what one of mine is, the other is an
Integrand. 

S-100 frobs from one company do not always work with those from
another.  I have made more than a few $$ by 'integrating' systems.
(i.e. making incompatible frobs foo with each other).  Be careful that
all the boards are known to work with each other. (I could produce a
list of what i know works with what.  Such a list, if added to by
others, so as to fill it out, would be invaluable).

Boards are not always equivalent, altho appearances may make it seem
otherwise.  The Morrow Switchboard and the SSM I/O-4 appear roughly
equivalent (in the I/O department) but the SSM is fully programmable
(i.e. baud rates and other such frobs are settable under software
control) while the Morrow is not. If you have a number of devices that
you rotate about (two printers, a modem, two terminals, and another
computer (like me)) then programmable baud rates might make life
easier (I, on the other hand, have to pull my IMSAI box out of the
rack, and reach into its bowels with a ball point pen to get to the
switches on the switchboard every time i move any peripherals around,
since i'm too cheap to buy another I/O board).

If you want a system that will be running by the end of the year, and
you are new to S-100, you might think about having a store 'integrate'
a system for you.  Or buy an 'integrated' S-100 system (a Cromemco
System 3 or Z2-D, or a North Star Horizon). 

Most manufacturers have quit shipping kits (Cromemco and North Star
have, Ithaca Intersystems will soon, if not already) since
kit-builders are not cost-effective -- they require too much technical
support and generate too little profit.  Stores also shy away from
kits for the same reasons.  Sales-persons often 'play stupid' so they
can spend their time selling systems (an activity that generates
revenues) rather than supporting old sales.  You can reasonably expect
to get 15-30minutes of support for every $100 you spend.  After that,
the seller is losing money on you (time is money, an hour spent on you
may mean a $10,000 sale that they lost) even if only the employee's
salary is in question.  If you get more support, you are gettng a good
deal.

Buy locally if you can. it makes life easier when you have problems.
Besides, it's always cheaper in the long run to have someone to go to
when things fail; saving on sales tax may be nice, but you will lose
big if it doesn't work.

Join the CP/M Users Group.

Subscribe to S-100 Microsystems (a magazine).

Have fun!!

My own systems are actually as follows:

#1:	   4MHZ, Z-80, 64K, CP/M 2.2
---	   -------------------------
	   IMSAI 8080 Mainframe w/30A power supply
	    and Godbout actively terminated motherboard.
	   Cromemco ZPU (2 or 4MHZ)
	   Central Data 64K Memory board
	   Tarbell Double Density Disk Controller (REV E)
	   Morrow Switchboard
	   Processor Tech 3P+S
	   Dual Shugart SA801s in custom box

notes:	   The Tarbell is flaky booting at 4MHz, but this is supposed
	   to be a problem that has been worked out by now. Lifeboat
	   has a really nice version of CP/M 2.2 for the Tarbell that
	   gets 600K on a side of a diskette.  The Tarbell is VERY
	   fast, and because of this, this is my favorite system.  The
	   Switchboard RS-232 drivers are not designed quite right,
	   and this leads to some very serious problems when
	   connecting the Morrow to a modem. I use the 3P+S for a
	   modem because of this. 

#2	   4MHz, Z-80, 48K, CP/M 1.4
---	   -------------------------

	   Custom box with SSM Motherboard and SSM terminator card,
	    SUNNY INT'L 30A power supply.
	   Ithaca Intersystems Z-80 CPU (rev 1.3)
	   Ithaca Intersystems Front Panel.
	   (3) Cromemco 16KZ  16K dynamic memory cards.
	   Morrow Discus 2D double density disk controller
	   Processor Tech 3P+S
	   Dual SHUGART SA801 in custom box.

notes:	   The Morrow is provided with some awfully silly bios drivers
	   that it much slower than it should ever need to be.  The
	   2.2 is so slow that I use 1.4 and the FAST program from
	   CPMUG #38, and it is almost as fast as the Tarbell, if
	   somewhat annoying.  The 1.4 will not automatically
	   determine density, but 2.2 will. Neither will let you boot
	   the system from a single density disk. The Morrow
	   controller has RAM, ROM, and a serial port on it. It has
	   memory mapped I/O, which I think is silly. (I have had to
	   modify countless programs because of this). It will also
	   not let you have a system bigger than 56K (as delivered
	   standard.  You can order a special one (for about $70.00
	   more) that will let you have a 62K system.). The Morrow has
	   worked with every memory board and CPU board that I have
	   ever tried with it.  That is a lot more than I can say for
	   the Tarbell.

#3	   Random Spares
---	   -------------
	   IMSAI CPU
	   IMSAI 4K Static RAM
	   (4) SSM 8K Static RAM (2102 type)
	   (3) MITS 4K Dynamic RAM
	   ZOBEX Systems 64K Dynamic RAM (a good board, better than
	    the CD) 
	   Polymorphics VTI rev 0.1
	   Polymorphics VTI rev 1.2
	   Polymorphics CPU (8080)
	   SSM CB1 (8080 CPU)
	   Cromemco 8K Bytesaver I (an excellent 2708 burner/holder)
	   Cromemco 32K Bytesaver III (an excellent 2516
	     burner/holder)
	   Cromemco 4FDC floppy controller (excellent, if overpriced)
	   Cromemco D+7A D/A, A/D interface
	   Crememco 8PIO 8 paralell port board
	   Cromemco PRI Centronice paralell printer card
	   Ithaca Intersystems Video Board
	   SSM 8K/16K Rom board (2708)
	   (2) Wangco 82 minifloppies.

#4	   Peripherals
---	   -----------
	   Teletype ASR 33
	   Integral Data Systems IDS 125
	   Anderson Jacobsen 841
	   DEC PDP 8I (i consider it a peripheral)
	   Perkin Elmer Fox 1100 (My baby.  Now out of production, but
	    my favorite terminal of all time.  This terminal has lots
	    of good humanoid engineering in it, and only a few flaws.
	    I like it better than VT100s or H19s even tho the latter
	    have more functions)
	   (2)DATAPOINT 3360 terminals (cheap & ugly & atrocious)
	   (1.5)Tektronix 4001 Graphics terminals with 4601 printers
	   (2)Cat Novation modems

#5	 The Ideal system (gleaned from my and my friends' experience)
--	 -------------------------------------------------------------
	   Ithaca Intersystems Mainframe (for front panel)
	   SD Systems CPU or Godbout 8085/8088 CPU (nice!!)
	   SD ddensity controller (Versafloppy II)
	   SD 64K Expandoram II
	   SSM I/O-4 or Morrow Switchboard
	   PMMI Modem-103
	   Centronics 703 or NEC Spinwriter (or both!!)
	   Perkin Elmer Fox (if you can find one) or Heath H19
	   (2)Per-Sci 299 or (2)Qume Datatrack double sided
	   VAX-11/750 (oops....not really)


Node: HomeBrew-B, Previous: HomeBrew-A, Up: HomeBrew, Next: HomeBrew-C

From: AEZ@MIT-AI, Feb 10, 1981

	I have at the present a homebrew CPD1802 (RCA's COSMAC) which
is similar to the RCA Microboard system. The processor is extremely
easy to interface as is very lenient in memory access time and
follows a rigid fetch execute cyle. The internal structure is that
there is sixteen 16 bit general registers, an 8 bit accumulator, two 4
bit pointers that show which register will be the PC and which will be
the stack and a 1 bit register called Q. The CPU supports one level of
interrupt (actually changes the PC pointer to register #1 and saves
the process's state) and DMA in and out on chip.
	The fact that the PC is a general register allows for special
microcode-like subroutines that can take immediate data. An unnestable
subroutine would simply change the PC pointer to a register that
points to the subroutine, to access the immediate data on the old
program flow, the old PC is used just like a stack, returns would just
change PC back to original.  I implemented the standard gosub/return
this way (they appear as three bytes for gosub and one byte for return
in the programs).  It also possible to implement relative address this
way. Also the copious amount of registers also allows for multiple
stacks or multiple quick subroutines (changing the PC pointer takes
one machine cycle).
	The main disadvantage of the 1802 is that all these 16 bit
registers are bottle necked by the 8 bit accumulator.  All
math/logical operations can only happen between accumulator and memory
(the stack pointer points to the data or can use immediate mode).
Moving data from register to register or memory (all implied
directions) must involve the accumulator (i.e. get the high byte of
reg. A, put into high byte of reg. B, get low byte of reg. A, put into
low byte of reg. B; two byte transfer= 4 opcodes and data passes
through accumulator). This bottle-necks the computer and wastes a lot
of opcodes (64 opcodes handle reg-acc & acc-reg alone, 255 opcodes
used by computer totally). Another problem is that the CPU is all
CMOS.  It's fine on power usage and allows alot of time for memory
access (it thinks it has CMOS memory all the time), but it loses on
speed. The typical 1802 can run 2-3Mhz and the fastest goes 6.4Mhz but
that is equivalent to a 6800 or 6502 running at 1/8 of that clock
speed.
	There is some interesting CMOS parts for the 1802 system but
they are limited by being CMOS.  For example, the graphics chip used
in the VIP,ELF and their brothers is ok for a $12.00 chip but it can
only access 8 bytes from the computer per video line giving the
maximum resolution of 64X128 dots and the minimum resolution of 64X32
dots (blocks?).
	All in all, the 1802 is a nice processor in the hardware
department for the first time hardware hackers (like myself) but it
lacks some in the software side (RCA believes that software is easier
than hardware), In the power side, the RCA microboards are hard to
beat when a CPU board, 16K of memory takes 23ma total from 5V (battery
backup memory boards can power the entire system for 32 hours or
retain memory alone for 96 hours).

	My homebrew system has 2K RAM, 1K ROM, the crufty video
display (I thought $12.00 was worth the risk), and hex keyboard and
LED's for I/O. Present cost about $130. Near future goal is IBM
Selectric I/O ( I have one at $330), a "real" video display (6.111
project, no cost projections yet), and some mass storage (I found an
8" disk drive that looks promising), and lots more memory (16 or 32K
dynamic problably). Projected costs will be about $600-$700 depending
on luck and cost trends.

			I hope this will be useful.
			Any questions to AEZ at AI.
			Adam Zilinskas

Node: HomeBrew-C,   Previous: HomeBrew-B,   Up: HomeBrew

From: PLATTS@WHARTON-10, Dec. 18, 1980

I am running an S100 based system, with an old TDL Xitan mainframe --
an 8-slot S100 motherboard with power supply and miscellaneous
circuitry. It was commercially available circa 1977-1979, and there
are many still around.  I have 36K of TDL's Z16 and 16K of Q&T Systems
RAM boards, a Z80 based CPU card (2 mhz), a TDL SMB IO (2K rom, 2K
ram, 3 Serial, 1 Parallel ports), SDS Versafloppy I with two 8" drives
(2 Shugart 800's in a random box with a random power supply).  Also a
Processor Technology 3P+S card.  My terminal is an H19, assembled by
myself, works perfectly, probably the most cost-effective one on the
market today.  Also a Decwriter, and a Pennywhistle modem.

The operating system is CDL's TPM, as is most system software
(assembler, linker, Basic). I run my own LISP.

Critical evaluation:
  Hardware: one memory board is flakey and should be replaced -- it
does not hold well with time.  The 3P+S is very difficult to
understand and adapt to a system.  Floppies are reliable.  
  Software:  quite good, the only complaints are (a): lack of a screen
editor, (b) non-standard mnemonics in assembler.  Outside of that, the
CDL assembler/linker is the finest I've seen for micros in terms of
flexibility. 

	-Steve Platt
	(4060 Irving St./Phila PA. 19104 215-222-6432)



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