Model 102 as a serial terminal for a Pidp8i

[Kehvarl]

After reading a lot of older mailing list posts, chasing completely the wrong solution, and finally learning what I did wrong, I present to you my Tandy Terminal Model 102 for the PiDP8i.





I _could_ have this log straight into the PDP simulator, but that doesn't respect 40x8 very well. It's still pretty usable though.


Setup was pretty simple:

First: acquire components:

• PiDP8i
• Tandy Model 102
• 25-pin RS232 to 9-pin RS232 serial cable
• Null-modem adapter
• USB Serial adapter

Second: hook things up

• Connect USB Serial adapter to Pi
• Attach Null Modem adapter to Serial Adapter
• Connect the 9-pin end of the serial cable to the null-modem
• Connect the 25-pin end of the serial cable to the RS232 port on the T102

Third: Some linux configuration on the Pi/PiDP8i

• In order to make all the work we're about to do useful, we'll need to create the terminfo for a t100/t102 so linux can be told how to handle the 40x8 character display. We could learn how that works and build it from scratch, or just copy the existing one that's floating around the internet. For that, create an empty file named model100 and copy in these contents:

trs100|Radio Shack Model 100:\
        :am:bs:xt:\
        :co#40:li#8:\
        :al=\EL:bl=^G:cd=\EJ:ce=\EK:cl=\EE:cm=\EY%+ %+ :\
        :cr=^M:dl=\EM:do=^J:ho=\EH:kb=^H:kd=^_:kl=^]:kr=^\:\
        :ku=^^:le=^H:nd=\034:se=\Eq:sf=^J:so=\Ep:up=\EA:\
        :ve=\EP:vi=\EQ:

• from the command line, run

  tic model100

• Now we have a trs100 terminfo definition that linux knows how to use.
• Next we'll copy the serial-getty template file that systemd uses into the place where it will look for the configuration for ttyUSB0

   sudo cp /lib/systemd/serial-getty@.service /etc/systemd/serial-getty@ttyUSB0.service

• Open the new serial-getty@ttyUSB0.servicefile in your favorite editor
  • Find the line that starts ExecStart=
  • Change it to

    ExecStart=-/sbin/agetty -o '-p -- \\u' 19200 %I trs100

  • In place of 19200 you can use any baud rate you like that the T102 supports
• From the command line run this command to start your new serial terminal

  sudo systemctl start serial-getty@ttyUSB0.service

• If you'd like the serial terminal available when linux starts, run:

  sudo systemctl enable serial-getty@ttyUSB0.service

Finally, we can have some fun with the T102!

• Start your T102
• Select and run the TELECOM program
• Use the STAT command to set the T102 to 98N1E
  • This sets the TELECOM communication to:
    • 9 19200 bps
    • 8 8 bits per character
    • N No Parity bit
    • E Enable XON/XOFF
• Use the TERM command to start your serial terminal session.
• Once logged into linux, you can run pidp8i to enter the simulated pdp8 from your T102
• Once connected to the PDP8 I recommend a nice romp in BASIC:
  • Make sure Caps-lock is enabled, just to make your life a little easier
  • R BASIC -- Run Basic
  • OLD -- Load an existing file
  • HELLO.BA -- Load the Petey P Eight virtual assistant
  • RUN -- Run the program
  • CTRL+C -- End the program when you're done
  • CTRL+C -- Exit BASIC
  • CTRL+D A -- Exit the PDP8 simulator and return to Linux

And finally another glamour shot of my latest fixation:

 

[whartung]

That's great. Grats on getting it all to work.