                           SIMH/HP 2100 RELEASE NOTES
                           ==========================
                             Last update: 2017-01-11


This file documents the release history of the simulator for the Hewlett-Packard
2114, 2115, 2116, 2100, 1000-M, 1000-E, and 1000-F machines.

The SIMH project does not issue discrete releases.  Instead, the current
simulator code base is available at:

  https://github.com/simh/simh

...and may be downloaded at any time.  A code snapshot is identified by the "git
commit ID" that is displayed by the simulator welcome banner.

Therefore, HP 2100 releases are simply documentation checkpoints that describe
the changes that have occurred since the last checkpoint.  Generally, a release
is written when one or more major changes have been incorporated.  Minor bug
fixes will be available immediately from the repository but only noted as part
of the next release document.



===================
General Information
===================

The simulator passes the HP 24396 offline diagnostic suite with some expected
failures due to unimplemented features.  For example, the disc diagnostic
error-correction logic tests and the tape diagnostic CRCC and LRCC tests fail,
as these features are not supported.  However, all features that are required
for operation of the supported HP operating systems pass their respective
diagnostic tests.  See the accompanying "hp2100_diag.txt" file for details.

The simulator has been tested with the following operating systems:

 - 2000E, 2000F, and 2000/Access Time-Shared BASIC.

 - DOS, DOS-M, and DOS-III.

 - RTE-II, RTE-III, RTE-IVB, and RTE-6/VM.

The user's manual for the simulator is provided in Microsoft Word format in the
"doc" subdirectory of the code base snapshot downloaded from the github site.  A
PDF version of the same manual is available at:

  http://alum.mit.edu/www/jdbryan/hp2100_doc.pdf


------------------
Available Software
------------------

A preconfigured RTE-6/VM disc image containing the operating system, the MACRO
assembler and Fortran 77 compiler, a selection of tape backup and restore
programs (READT/WRITT, READR/SAVER, FC, TF, and FST), an example programs
(/KENC/HELLO.FTN), and the Mystery Mansion game (MMM) is available from
Bitsavers at:

  http://www.bitsavers.org/bits/HP/tapes/rte-6vm/rte6200/

The archive contains instructions and simulator command files that allow
ready-to-run operation.

The Computer History Museum has graciously arranged with HP to offer the HP 1000
Software Collection with a sublicense for non-commercial use by private
individuals.  The Collection is hosted by Bitsavers at:

  http://www.bitsavers.org/bits/HP/HP_1000_software_collection/

A preconfigured RTE-IVB disc image containing the operating system, the ASMB
assembler and FORTRAN IV compiler, and the READR/SAVER and FC tape backup and
restore programs is available from the HP Computer Museum at:

  http://www.hpmuseum.net/display_item.php?sw=565

The archive contains instructions and a simulator command file.

QCTerm, an HP 700 terminal emulator for Microsoft Windows, is available from the
HP Computer Museum at:

  http://www.hpmuseum.net/display_item.php?sw=585

Use of an HP terminal via a serial port or terminal emulator via Telnet enables
more advanced screen editing features of the RTE operating systems.

Manuals describing the operation of HP software are available from Bitsavers at:

  http://www.bitsavers.org/pdf/hp/1000/
  http://www.bitsavers.org/pdf/hp/2000TSB/
  http://www.bitsavers.org/pdf/hp/21xx/

...and from the HP Computer Museum at:

  http://www.hpmuseum.net/collection_document.php


----------------
Year 2000 Issues
----------------

RTE-6/VM Revision 6200 is Y2K compliant, except for the READR and SAVER
programs.  The errors are cosmetic only.

RTE-IVB Revision 5010 is not Y2K compliant.  All of the failures are in
subsystems; the operating itself (time-of-day clock) accommodates dates through
2059.  All of the errors are cosmetic.  Typically, punctuation characters appear
in the years, e.g., "19:0" for 2000.  The RTE-IVB software kit from the HP
Computer Museum includes fixes for the affected modules to bring the system into
compliance.

All other HP operating systems are not Y2K compliant.


-----------------------------
Bugs in RTE-IVB Revision 5010
-----------------------------

Testing during simulator development revealed the presence of a bug in RTE-IVB
Revision 5010:

 - The $BALC module in the system library has a bug that causes memory
   corruption.  This module is used by the ACCTS program and manifests itself by
   printing gibberish after the "PLEASE LOG ON:" prompt.

   Specifically, the internal MXEV routine performs a cross-store indirect via a
   location in Table Area II (XSA $MAXI+0,I).  This fails because the indirect
   chain is resolved in the user map, but TA II is not in the user map of
   large-background programs, such as ACCTS.  Therefore, the location in the
   user map corresponding to $MAXI in the system map is used as the pointer to
   the location to store.

   A corrected version of $BALC is present on cartridge GF of the disc image
   supplied with the RTE-IVB software kit at the HP Computer Museum.



======================
Release 25, 2017-01-11
======================

This is the initial checkpoint release of the HP 2100 simulator, corresponding
to the 25th set of changes to the 4.0 code base.  The following devices are
currently simulated:

  - 2114C CPU with up to 16 KW of memory
  - 2115A CPU with up to 8 KW of memory
  - 2116C CPU with up to 32 KW of memory
  - 2100A CPU with up to 32 KW of memory
  - 1000 M/E/F-Series CPU with up to 1024 KW of memory
  - EAU, FP, IOP, DMS, FFP, DBI, VIS, and SIGNAL microcode extensions
  - RTE-IV EMA or RTE-6/VM OS and VMA microcode extensions
  - 12531C Buffered Teleprinter Interface with one 2752 Teleprinter
  - 12539C Time Base Generator
  - 12557A Disc Controller with four 2870 drives
  - 12559C Magnetic Tape Controller with one 3030 drive
  - 12565A Disc Controller with two 2883 drives
  - 12566B Microcircuit Interface with a loopback connector
  - 12578A Direct Memory Access Controller
  - 12581A Memory Protect
  - 12597A Duplex Register Interface with one 2748 Paper Tape Reader
  - 12597A Duplex Register Interface with one 2895 Paper Tape Punch
  - 12606B Fixed Head Disc Controller with one 2770/2771 drive
  - 12607B Direct Memory Access Controller
  - 12610B Drum Controller with one 2773/2774/2775 drive
  - 12620A Privileged Interrupt Fence
  - 12653A Printer Controller with one 2767 Line Printer
  - 12792C 8-Channel Asynchronous Multiplexer
  - 12821A Disc Interface with four 7906H/7920H/7925H drives
  - 12845B Printer Controller with one 2607 Line Printer
  - 12875A Interprocessor Link
  - 12892B Memory Protect
  - 12895A Direct Memory Access Controller
  - 12897B Dual-Channel Port Controller
  - 12920A 16-Channel Terminal Multiplexer
  - 12936A Privileged Interrupt Fence
  - 12966A Buffered Asynchronous Communications Interface
  - 13037D Disc Controller with eight 7905/7906/7920/7925 drives
  - 13181A Magnetic Tape Controller with four 7970B drives
  - 13183A Magnetic Tape Controller with four 7970E drives
  - 13210A Disc Controller with four 7900 drives

The "HP 2100 Simulator User's Guide" manual describes the configuration and
operation of each of these devices in detail.


--------------------
Implementation Notes
--------------------

 - New bug fixes will now be listed in this file under the associated release
   rather than in their previous location (hp2100_bugfixes.txt).

 - Starting with the next release, the LOAD command will restrict its operation
   to the addresses occupied by the bootstrap loaders, i.e., the last 64
   locations in memory (up to 32K), unless forced by the addition of the "-F"
   switch.  The LOAD command is not designed for general loading of absolute
   binary files, as it does not initialize the A and B registers as some HP
   software expects.  It is intended only to install bootstrap loaders.  The
   BOOT PTR command is the proper simulation of the hardware absolute paper tape
   loader.


----------
Bugs Fixed
----------

  1. PROBLEM:  DPC device documentation uses the wrong disc drive model number.

     VERSION:  Release 24.

     OBSERVATION:  The comments in the hp2100_dpc.c source file and Section 2 of
     the "HP2100 Simulator User's Guide" say that the DPC device supports the
     2871 disc drive, while Section 2.6.1 of the User's Guide says that the
     support is for the 2781 disc drive.  Neither of these model numbers is
     correct.

     Contemporaneous literature (e.g., the "2116B Computer Price List," dated
     June 1970) states that the disc memory subsystem consists of the HP 2870A
     Moving Head Disc, HP 2871A Disc Controller, HP 2881A Power Supply, and HP
     2882A Cabinet.

     CAUSE:  The controller model number is used instead of the drive model
     number, while the "2781" number is a transposition of "2871."

     RESOLUTION:  Modify the initial comments in the DPC device source file
     (hp2100_dpc.c) and modify the sections of the HP2100 Simulator User's Guide
     to use the correct disc drive model number (2870).

     STATUS:  Fixed in Release 25.


  2. PROBLEM:  The BOOT DRC command does not execute correctly.

     VERSION:  Release 24.

     OBSERVATION:  Attempting to boot DOS from a fixed-head disc or drum does
     not work.  The CPU sits in a loop waiting for DMA to finish, but it never
     does.

     CAUSE:  The DMA control word in the DR device bootstrap is not configured
     during BOOT DRC processing, so DMA is communicating with the wrong device.

     RESOLUTION:  Modify "drc_boot" (hp2100_dr.c) to set the fixed disc/drum
     select code into the DMA control word before returning.

     STATUS:  Fixed in Release 25.


  3. PROBLEM:  The valid command "DEPOSIT 2000 JMP 2001" is rejected.

     VERSION:  Release 24.

     OBSERVATION:  Regarding symbolic input, the HP2100 User's Manual says that
     the "C" and "Z" flags, signifying a current-page or zero-page reference,
     respectively, are not needed "...when entering [memory reference]
     instructions into CPU memory; the simulator figures out from the target
     address what mode to use."  While the valid command "DEPOSIT 1000 JMP 1001"
     correctly enters a zero-page jump into memory, the valid command "DEPOSIT
     2000 JMP 2001" does not enter a current-page jump.  Instead, an "Invalid
     argument" error occurs.

     CAUSE:  The "parse_sym" routine looks for the optional "C" or "Z" flag when
     parsing memory reference instructions and sets a flag if either is
     specified.  The test for a current-page reference is performed only if the
     reference type was not explicitly specified.  However, the sense of the
     test is reversed.

     RESOLUTION:  Modify "parse_sym" (hp2100_sys.c) to correct the test for C/Z
     option specification.

     STATUS:  Fixed in Release 25.


  4. PROBLEM:  The invalid command "DEPOSIT 2000 JMP C 2001" is accepted.

     VERSION:  Release 24.

     OBSERVATION:  Regarding symbolic input, the HP2100 User's Manual says that
     "The address is an octal number in the range 0 - 77777; if C or Z is
     specified, the address is a page offset in the range 0 - 1777."  However,
     specifying a page offset > 1777 is accepted without complaint if it is
     within the current page range.

     CAUSE:  Error checking for memory reference instruction entry is
     incomplete.

     RESOLUTION:  Modify "parse_sym" (hp2100_sys.c) to ensure that the range
     check is enforced if either C or Z is specified.

     STATUS:  Fixed in Release 25.


  5. PROBLEM:  Punched output does not appear on TTY devices lacking a paper
     tape punch.

     VERSION:  Release 24.

     OBSERVATION:  Running the HP contributed library program "HP 2000F BASIC
     for DOS-M/DOS III" does not produce any console output when using terminal
     driver DVR00 as required by the program.  When using alternate terminal
     driver DVR05, console output appears but console input does not work
     properly.

     CAUSE:  DOS-M and DOS-III support two modes of console I/O: ASCII mode and
     binary mode.  ASCII mode appends carriage-return/line-feed characters on
     output and strips them on input.  Binary mode sends and receives bytes
     exactly as supplied.

     DVR00 is required because DVR05 does not support the binary I/O mode
     required by the program.  However, DVR00 assumes that a binary write is to
     be directed to the console's paper tape punch rather than the console
     printer and therefore sets the TTY interface's "punch flip-flop" instead of
     the "print flip-flop" to accompany the text output.  The simulation of the
     HP 12531 interface card associated with the TTY device discards output if
     the punch flip-flop is set and the punch unit (TTY2) is not attached.

     The problem occurs because only a connected HP 2754 teleprinter (a modified
     Teletype ASR35) reacts to the print and punch flip-flop signals.  All other
     supported terminal devices ignore the signals and print whatever output is
     supplied (an HP 2752 -- a rebadged ASR33 -- has a manual control for the
     punch, but the punch and printer operate together when the punch is on).
     The 2000F BASIC program apparently was designed for use with one of these
     other terminals, which print normally even though only the punch flip-flop
     is set.

     RESOLUTION:  Modify "tto_out" (hp2100_stddev.c) to honor the print and
     punch flip-flop settings and separate the output as directed only if the
     console punch unit is attached (simulating an HP 2754).  When the unit is
     detached, all output is delivered to the console printer, regardless of the
     flip-flop settings (simulating all other console devices).

     STATUS:  Fixed in Release 25.
