The PDP-8, developed in 1964, was the first mass produced minicomputer. It was developed at the DEC plant in Reading, England. It sold for about $18,500 to $20,000.
The PDP-8 was a 16-bit machine. The PDP-8 was also known as the "Classic 8." It used the newly announced R Series logic.
So you've built a PiDP-8, now what? Here are some things I've learned.
When you first boot the PiDP-8 you will see something like the following:
PDP-8 simulator V4.0-0 Current git commit id: 4e0450cf
PiDP-8/I pi4-gpio-hack:id[bd10d4dde2] [pi4b] [ils] [stdpcb] [gpio] [rt]Loading OS/8 from the RK05 cartridge disk...
PiDP-8/I pi4-gpio-hack:id[bd10d4dde2] - OS/8 V3D - KBM V3Q - CCL V1F
Configured by pi@raspberrypi on 2020.02.18 at 12:35:20 PST
Restart address = 07600
Type:
.DIR - to get a list of files on DSK:
.DIR SYS: - to get a list of files on SYS:
.R PROGNAME - to run a system program
.HELP FILENAME - to type a help file
If you type DIR at the prompt you will get a listing of files, which are games and their supporting files. Those games ending in .BA (meaning BASIC) can be run by typing:
Wumpus
.R BASIC
NEW OR OLD--OLD
FILE NAME--RKB0:WUMPUS [or whatever game file]
RUN
However, Chess is run by just typing:
Chess
.R CHESS
Finally about Adventure.
.R FRTS
*ADVENT$ ⇠ $ = Escape keypress
Run Adventure
.R RFTS
*ADVENT$ ⇠ The $ sign is produced by pressing the Esc key
to quit
SUSPEND
to save game
.SA SYS ADV
to re-run
.R ADV
If you run into errors or issues running Adventure then what you need to do is restore the ADVENT.LD file. In order to restore its:
From within the simulator, press Ctrl-E to get out to the SIMH command prompt, then follow this script:
sim> att dt0 /opt/pidp8i/share/media/os8/subsys/advent.tu56
sim> cont
.COPY DSK:<DTA0:ADVENT.LD
Manually program in a timer
Do the following entry:
First we choose an address. The address can be arbitrary, but let's enter 10, then Load Add.
Enter the accumulator command. 7001, Dep.
Delay instruction to slow down: 2034
Jump back to previous instruction for delay: 5011
2035
5013
2036
5015
2037
5017
Jump to first instruction: 5010
Now let's enter the halt command. 7402, Dep.
So we can then go back to the address, push on Single Step, Start and Cont to see each step.