Slashdot Mirror
Spacewar! Lives Again
hws writes "A DEC PDP1 emulator running the original version of Spacewar! is online here.
A group at MIT created a PDP1 emulator in Java. The original Spacewar! sources were assembled with a PDP1 Assembler written in Pearl.
The emulator, assembler and game sources are available at this site.
For those of you too young to remember, Spacewar! is probably the first video game and was done back in 1962. It and the scene that spawned it were extensively covered in Steven Levy's book - Hackers."
Pong was the first VIDEO game, not computer game. Two completely different things. BTW, if you want to play REAL Pong, ask me for Poing. It's an open-source pong clone I made for DOS. Not the greatest, as it is my first C game...
The long-neglected (but recently renewed!) MESS emulator, little sister to MAME, also emulates a PDP-1 and Spacewar.
Executables and source are available for Mac, DOS, Windows and some Unix flavors, I believe.
Check it out: http://mess.emuverse.com
-A.
---
What did the walrus say to the penguin? "No soap, radio."
The PDP1 had a display.. sort of.. It was one of the most interesting things about it compared to the TX-0 that the MIT hackers had used before. It was actually more like a older oscilloscope and I can't imagine that it was very easy to do anything useful with it. Steve Russell apparently apparently spent close to a month getting a tiny dot on the screen that you could move with the controls.
Actually, they didn't have text yet. Text was a very advanced display capability yet to be seen. Spacewar's display involved an oscilloscope and a ramp generator. :) (Remember the Vectrex, or the original Star Wars arcade game?)
---
"'Is not a quine' is not a quine" is a quine.
"'Is not a quine' is not a quine" is a quine.
Quine "quine?
I played with this a couple of years ago. There was (probably still is) a PDP-11 emulator you could download from ftp.dec.com. With the provided disk images, you could run V7 UNIX. I played with it for a while; I was able to log in, wrote a little C program using ed, and then compile and run it. Here, I think I found the link! (ftp://ftp.digital.com/pub/DEC/sim/).
Wordcodes are technically just an extension of bytecodes; instead of being 8 bits long, they're longer. A common length is 16 bits.
They're faster and smaller because there are so many more possible ones -- the VM can have many more primitives which are more tailored to the job at hand. They're more secure for the same reason; it's possible to design an instruction set which does not have as many illegal combinations of primitives.
You still need a security manager, of course, but the verifier can be much smaller and quicker.
Secure in what sense?
Secure in the sense that a verifier has to watch for much fewer conditions, and is thus simpler to build. Once you've built the verifier, of course, both systems have the same security.
An example of a wordcoded system is threaded Forth. I don't know whether anyone has made a portable executable format out of wordcodes.
-Billy