A fork of the Python PDP-8 emulator with added Blinkenlights. Needs PyGame.
The top row of lights shows the program counter and the bottom row the accumulator.
To quit the program, press Ctrl+C to return to the monitor, then enter q.
PDP-8 front panel photo by David Gesswein. ASR-33 teletype sounds by 262LongRunner@YouTube.
Running the Chekmo chess program
python3 pdp8.py load r Enter a White move, e.g. "E2-E4" and then "PB" for the computer to play Black.
$ python3 pdp8.py pygame 2.0.1 (SDL 2.0.14, Python 3.9.1) Hello from the pygame community. https://www.pygame.org/contribute.html PDP-8 simulator v0.000001, (c) 2020 j. dersch PC 0000 AC 0000 L 0 SW 0000 IE 0 > load PC 0200 AC 0000 L 0 SW 0000 IE 0 > r CHEKMO-II W. YOUR MOVE? E2-E4 B. YOUR MOVE? PB B. D7-D5 W. YOUR MOVE? Here is a game between Stockfish and Chekmo, with analysis provided by SCID:
But always remember to only watch those pretty blinkenlights... :)
rim pt shifter.rim r Press <Ctrl-C> when loading has finished pc 100 Now repeatedly enter "s" to single-step through the program and watch the accumulator increase every few steps.
The FOCAL programming language
$ python3 pdp8.py pygame 2.0.1 (SDL 2.0.14, Python 3.9.1) Hello from the pygame community. https://www.pygame.org/contribute.html PDP-8 simulator v0.000001, (c) 2020 j. dersch PC 0000 AC 0000 L 0 SW 0000 IE 0 > load focal PC 0200 AC 0000 L 0 SW 0000 IE 0 > r CONGRATULATIONS!! YOU HAVE SUCCESSFULLY LOADED 'FOCAL,1969' ON A PDP-8 COMPUTER. SHALL I RETAIN LOG, EXP, ATN ?:NO SHALL I RETAIN SINE, COSINE ?:NO PROCEED. *W C-FOCAL,1969 Now enter some FOCAL code at the "*" prompt, e.g. this FOR loop which TYPEs numbers, and then use GOTO to run the program. (In FOCAL, commands can be abbreviated by just using their first character.)
*1.1 F X=1,1,5; T X,! *G = 1.0000 = 2.0000 = 3.0000 = 4.0000 = 5.0000 Use "W" to list the program and "E ALL" to delete it.
The "auto" monitor command auto-types a text file into the terminal. If you are getting errors during input such as "?11.35" or "?01.40", you need to increase the value of AUTODELAY in the script, e.g. "AUTODELAY=.1".
Several FOCAL source code files are included:
- lunar.fc (Lunar Lander)
- ham.fc (Hamurabi)
- mand.fc (Mandelbrot set)
- fib.fc (Fibonacci numbers)
- eras.fc (Sieve of Eratosthenes)
- pas.fc (Pascal's triangle)
- cell.fc (Elementary cellular automaton)
Note that lunar.fc and ham.fc need a lot of free RAM, so you need to answer "NO" to the FOCAL startup questions!
$ python3 pdp8.py pygame 2.0.1 (SDL 2.0.14, Python 3.9.1) Hello from the pygame community. https://www.pygame.org/contribute.html PDP-8 simulator v0.000001, (c) 2020 j. dersch PC 0000 AC 0000 L 0 SW 0000 IE 0 > load focal PC 0200 AC 0000 L 0 SW 0000 IE 0 > r CONGRATULATIONS!! YOU HAVE SUCCESSFULLY LOADED 'FOCAL,1969' ON A PDP-8 COMPUTER. SHALL I RETAIN LOG, EXP, ATN ?:NO SHALL I RETAIN SINE, COSINE ?:NO PROCEED. *CTRL-C halt PC 2670 AC 0000 L 0 SW 0000 IE 1 > auto ham.fcl PC 2670 AC 0000 L 0 SW 0000 IE 1 > r .... <computer reads program text> *G HAMURABI: LAST YEAR = 0 STARVED, = 5 ARRIVED, POPULATION IS= 100 THE CITY OWNS= 1000 ACRES. WE HARVESTED= 3 BUSHELS PER ACRE; RATS ATE = 200 BUSHELS, YOU NOW HAVE = 2800 BUSHELS IN STORE. HAMURABI: LAND IS TRADING AT= 18 BUSHELS PER ACRE; HOW MANY ACRES OF LAND DO YOU WISH TO BUY? $ python3 pdp8.py pygame 2.0.1 (SDL 2.0.14, Python 3.9.1) Hello from the pygame community. https://www.pygame.org/contribute.html PDP-8 simulator v0.000001, (c) 2020 j. dersch PC 0000 AC 0000 L 0 SW 0000 IE 0 > load focal PC 0200 AC 0000 L 0 SW 0000 IE 0 > r CONGRATULATIONS!! YOU HAVE SUCCESSFULLY LOADED 'FOCAL,1969' ON A PDP-8 COMPUTER. SHALL I RETAIN LOG, EXP, ATN ?:NO SHALL I RETAIN SINE, COSINE ?:NO PROCEED. *CTRL-C halt PC 2671 AC 0000 L 0 SW 0000 IE 1 > auto mand.fc PC 2671 AC 0000 L 0 SW 0000 IE 1 > r .... <computer reads program text> *G ********************************************************************** ********************************************************************** **************************************************** ***************** ************************************************* *************** ************************************************* *************** **************************************** * ********** *************************************** * ****** ************************************* ***** ********************** **** ******* **** *********************** ** ** ********************* **** *** * ******* ********************* **** *********************** ** ** ********************** **** ******* **** ************************************* ***** *************************************** * ****** **************************************** * ********** ************************************************* *************** ************************************************* *************** **************************************************** ***************** ********************************************************************** ********************************************************************** **********************************************************************