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wfjm.w11/doc/w11a_os_guide.md
2022-08-20 08:37:33 +02:00

14 KiB

Guide to run operating system images on w11a systems

Table of content

I/O emulation setup

All UNIBUS peripherals which exchange data (currently DL11, DZ11, LP11, PC11, DEUNA, RK11, RL11, RPRH, and TM11) are currently emulated via a backend process. The communication between the FPGA board and backend server can be via

  • Serial port

    • via an integrated USB-UART bridge
      • on Arty A7, Basys3, Cmod A7 and Nexys4, and Nexys A7 with an FT2232HQ, allows up to 12M Baud
      • on Nexys3 with an FT232R, allows up to 2M Baud
      • for all FTDI USB-UART it is essential to set them to low latency mode. That was the default for Linux kernels 2.6.32 to 4.4.52. Since about March 2017, one gets kernels with 16 ms default latency again, thanks to kernel patch 9589541. On newer systems, it is essential to install a udev rule which automatically sets low latency, see the documentation in tools/sys.
    • via RS232 port, as on S3board and Nexys2
      • using a serial port (/dev/ttySx) is limited to 115 kBaud on most PCs.
      • using a USB-RS232 adapter was tested up to 460k Baud.
  • Direct USB connection using a Cypress FX2 USB controller

    • is supported on the Nexys2 and Nexys3 FPGA boards
    • much faster than serial port connections (see below)
    • also allows configuring the FPGA over the same USB connection
  • Notes:

    • A 12M Baud connection, like on a Nexys4, gives disk access rates and throughputs much better than the real hardware of the 70's and is well suitable for practical usage.
    • In an OS with good disk caching like 2.11BSD the impact of disk speed is actually smaller than the bare numbers suggest.
    • A 460k Baud connection gives in practice a disk throughput of ~20 kB/s. This allows to test the system but is a bit slow for real usage.
    • USB-RS232 cables with an FTDI FT232R chip work fine, tests with Prolific Technology PL2303 based cable never gave reliable connections for higher Baud rates.

Recommended setup for best performance (boards ordered by vintage):

Board Channel/Interface nom. speed peak transfer rate
Arty S7 USB-UART bridge 12M Baud 1090 kB/sec
Arty A7 USB-UART bridge 12M Baud 1090 kB/sec
Basys3 USB-UART bridge 12M Baud 1090 kB/sec
Cmod A7 USB-UART bridge 12M Baud 1090 kB/sec
Nexys A7 USB-UART bridge 12M Baud 1090 kb/sec
Nexys4 USB-UART bridge 12M Baud 1090 kb/sec
Nexys3 Cypress FX2 USB USB2.0 speed 30000 kB/sec
Nexys2 Cypress FX2 USB USB2.0 speed 30000 kB/sec
S3board RS232+USB-RS232 cable 460k Baud 41 kB/sec

FPGA Board setup

Recommended setups

  • Arty A7 or Arty S7

    • connect USB cable to micro-USB connector labeled 'J10'
    • to configure via Vivado hardware server make <sys>.vconfig
  • Basys3

    • connect USB cable to micro-USB connector labeled 'PROG'
    • to configure via ivado hardware server make <sys>.vconfig
  • Cmod A7

    • connect USB cable to micro-USB connector
    • to configure via Vivado hardware server make <sys>.vconfig
  • Nexys4 and Nexys A7 (or Nexys4 DDR)

    • connect USB cable to micro-USB connector labeled 'PROG'
    • to configure via Vivado hardware server make <sys>.vconfig
  • Nexys3

    • use Cypress FX for configure and and rlink communication
    • connect USB cable to micro-USB connector labeled 'USB PROG'
    • to configure via FX2 and jtag tool make <sys>.jconfig
  • Nexys2

    • connect USB cable to mini-USB connector (between RS232 and PS/2 port)
    • to configure via FX2 and jtag tool make <sys>.jconfig
  • S3board

    • connect the USB-RS232 cable to the RS232 port
    • connect a JTAG programmer (e.g. Xilinx USB Cable II) to JTAG pins
    • to configure via ISE Impact make <sys>.iconfig

All examples below use the same basic setup

  • set up vt100 emulator windows

      cd $RETROBASE/tools/oskit/<oskit-name>
      console_starter -d DL0 &
      console_starter -d DL1 &
    
  • set up rlink connection using ti_rri backend server via the ti_w11 quick start wrapper script. Ensure that all 8 switches on the board are in the indicated positions (SWI=...). The concrete boot script name is given in the following sections

    • for sys_w11a_arty or sys_w11a_as7 over serial

        SWI = 0110                (gives console light emulation...)
        ti_w11 -tuD,12M,break,xon  @<oskit-name>_boot.tcl
      
    • for sys_w11a_b3 over serial

        SWI = 00000000 00101000   (gives console light display on LEDS)
        ti_w11 -tuD,12M,break,xon  @<oskit-name>_boot.tcl
      

      Note: the basys3 w11a has only 176 kB memory (all from BRAMS!). u5ed works fine. XXDP, RT11 and RSX-11M should work. 211bsd will not boot, neither most RSX-11M+ systems.

    • for sys_w11a_c7 over serial

        ti_w11 -tuD,12M,break,xon  @<oskit-name>_boot.tcl
      

      Note: the c7 w11a has only 672 kB memory (512 SRAM + 160 BRAM). u5ed, u7ed, XXDP, RT11, RSX-11M and most most RSX-11M+ systems should work. 211bsd works only in the 'non-networking' configuration 211bsd_rpmin.

    • for sys_w11a_n4 or sys_w11a_n4d over serial

        SWI = 00000000 00101000   (gives console light display on LEDS)
        ti_w11 -tuD,12M,break,cts  @<oskit-name>_boot.tcl
      
    • for sys_w11a_n3 or sys_w11a_n2 over fx2

        SWI = 00101100
        ti_w11 -u @<oskit-name>_boot.tcl
      
    • for sys_w11a_s3 over serial

        SWI = 00101010
        ti_w11 -tu<dn>,460k,break,xon @<oskit-name>_boot.tcl
      

      Notes:

      • the letter after -tu is either the serial device number, denoted as <dn>, or the letter D for auto-detection of Digilent boards with an FT2232HQ based interface.

        • for Arty A7, Basys3, Cmod A7, Nexys4, and Nexys A7 board simply use D
        • otherwise check with ls /dev/ttyUSB* to see what is available
        • <dn> is typically '1' if a single FT2232HQ based board is connected, like an Arty, Basys3, Cmod A7, or Nexys4. Initially, two ttyUSB devices show up, the lower is for FPGA configuration and will disappear when the Vivado hardware server is used once. The upper provides the data connection.
        • <dn> is typically '0' if only a single USB-RS232 cable is connected
      • on LED display

        • is controlled by SWI(3)

              0 -> system status
              1 -> DR emulation --> OS specific light patterns
          
      • on Hex display

        • is controlled by SWI(5:4)

        • boards with a 4 digit display

              00 -> serial link rate divider
              01 -> PC
              10 -> DISPREG
              11 -> DR emulation
          
        • boards with 8 digit display

              SWI(5) select for DSP(7:4) display
                  0 -> serial link rate divider
                  1 -> PC
              SWI(4) select for DSP(3:0) display
                  0 -> DISPREG
                  1 -> DR emulation
          

SimH simulator setup

Sometimes it is good to compare the w11a behavior with the PDP-11 software emulator from the SimH project. See INSTALL_simh for installation instructions and supported versions.

Under $RETROBASE/tools/simh two setup files are provided which configure SimH to reflect the w11a setup as close as possible:

  • setup_w11a_min.scmd
    Very close to the current w11a state when it runs on an s3board
    • processor: 11/70, no FPP, 1 Mbyte
    • periphery: 2 DL11, LP11, RK11, PC11
  • setup_w11a_max.scmd
    Planned configuration for the w11a, in addition
    • processor: 4 Mbyte memory (as on Nexys2, Nexys3,...)
    • periphery: in addition DZ11, RL11/RL02, RK70/RP06, TM11/TU10

Startup scripts are provided with each oskit. They call the w11a_max configuration, so will show in the emulator what w11a can do when finished.

All examples below use the same basic setup

  • set up vt100 emulator window for 1st and 2nd DL11

       cd $RETROBASE/tools/oskit/<oskit-name>
       console_starter -s -d DL0 &
       console_starter -s -d DL1 &
    

    Note: the -s ensures that the port numbers used by SimH are taken!

  • start the simulator

       pdp11 <oskit-name>_boot.scmd
    

oskits

Ready to be used 'oskits' are provided under

 $RETROBASE/tools/oskit/<oskit-name>

The tarballs with the disk images are provided from a web server and have to be installed separately.

Unix systems

Ancient UNIX systems for the PDP-11 can now be freely used under the 'Caldera license'. 2.11BSD was released 1992 under the 4 clause BSD license. Taken together

  • Unix V1 to V7
  • all BSD Unix versions for PDP-11

can be freely distributed and used for non-commercial purposes.

Several oskits are provided:

oskit Name OS Disk/Tape Comment
u5ed_rk Unix 5th Ed. System RK05
u7ed_rp Unix 7th Ed. System RP04 very preliminary, port to w11a in progress
211bsd_rk 2.11BSD system RK05 very elementary subset
211bsd_rl 2.11BSD system RL02 small subset
211bsd_rp 2.11BSD system RP06 full system
211bsd_rpmin 2.11BSD system RP06 full system; tuned for small memory (min 512 kB, better 640 kB)
211bsd_rpeth 2.11BSD system RP06 full system; with DEUNA Ethernet

For further details consult the README.md file in the oskit directory.

DEC operating systems

Unfortunately, there is no general hobbyist license for DEC operating systems for PDP-11 computers. The 'Mentec license' is commonly understood to cover some older versions of DEC operating systems, for example

  • RT-11 V5.3 or prior
  • RSX-11M V4.3 or prior
  • RSX-11M PLUS V3.0 or prior

on a simulator. It is commonly assumed that the license terms cover the usage of the PDP11 simulator from the 'SimH' suite. Usage of the e11 simulator is not covered according to the author of e11.

THIS LICENSE DOES NOT COVER THE USAGE OF THESE HISTORIC DEC
OPERATING SYSTEMS ON ANY 'REAL HARDWARE' IMPLEMENTATION OF A
PDP-11. SO USAGE ON THE W11 IS NOT COVERED BY THE 'Mentec-license'.

Some oskits are provided with systems sysgen'ed to run on a configuration like the w11a.

  • Feel free to explore them with the SimH simulator. The boot scripts for SimH are included ( <kit>.simh )

  • In case you happen to have a valid license feel free to try them out the w11a and let the author know whether is works as it should. For convenience the boot scripts are also included ( <kit>.tcl ).

Several oskits are provided:

oskit Name OS Disk/Tape Comment
rsx11m-31_rk RSX-11M V3.1 RK05
rsx11m-40_rk RSX-11M V4.0 RK05
rsx11mp-30_rp RSX-11M+ V3.0 RP06
rt11-40_rk RT-11 V4.0 RK05
rt11-53_rl RT-11 V5.3 RL02
xxdp_rl XXDP 22 and 25 RL02

For further details consult the README.md file in the oskit directory.