4 ms·

What kind of CPU drove the logic? This seems to be missing from the article. It describes an iterative compile/debug cycle but leaves out the part where why t

What kind of CPU drove the logic? This seems to be missing from the article. It describes an iterative compile/debug cycle but leaves out the part where why the DEC computer was needed to make a tape for a Forth debugging machine - we are never told how that Forth thing made the final leap to the stand up cabinet hardware or if the tape thing also went to the cabinet after it was debugged.

dmitrygr 9y ago
6502
g051051 9y ago
The game used a 6502 for the main CPU, but had a custom system called "Math box" that handled the 3D computations: > The Math Box was built around the AMD 2901 Bit Slice which contained an Arithmetic/Logic Unit, a 16-deep dual port RAM, two registers, and a multiplexer. Each one was only 4-bits but had hooks so that it could be expanded. Four were used to produce a 16-bit machine and they were controlled by another State Machine. > Battlezone was the first game to use a new development system: the Blue Box and White Box duo. The Blue Box was programmed in Forth and controlled the emulator/analyzer in the White Box. It also had an external 8" floppy disk drive as well as a serial port for connecting to the VAX. Unfortunately, it did not have a full featured editor/assembler. Editing/assembling/linking was originally done on the department's PDP11 Model 20s which placed the output file on an 8" floppy, which could then be loaded by the Blue Box. > Later, when we got the first VAX, the Blue Box could be used as a terminal and the VAX was used to edit, assemble and link the program, and the output could be downloaded into the Blue Box/White Box.
ilaksh 9y ago
This is a starting point https://github.com/mamedev/mame/blob/master/src/mame/drivers/tempest.cpp https://github.com/mamedev/mame/blob/master/src/mame/drivers...
kabdib 9y ago
Games were cross-assembled on a VAX (using a modified version of the DEC macro assembler). I never saw the "blue FORTH box" but it was probably a ROM emulator of some kind that you downloaded code to, with some FORTH words for doing low-level stuff like debugging, resetting the target and diagnostics. The game itself was not written in FORTH. I'd forgotten that some programmers depended on other people keyboarding their source code. I think this was largely a coin-op thing; the other engineering departments never practiced that.

dmitrygr 9y ago

6502

g051051 9y ago

The game used a 6502 for the main CPU, but had a custom system called "Math box" that handled the 3D computations: > The Math Box was built around the AMD 2901 Bit Slice which contained an Arithmetic/Logic Unit, a 16-deep dual port RAM, two registers, and a multiplexer. Each one was only 4-bits but had hooks so that it could be expanded. Four were used to produce a 16-bit machine and they were controlled by another State Machine. > Battlezone was the first game to use a new development system: the Blue Box and White Box duo. The Blue Box was programmed in Forth and controlled the emulator/analyzer in the White Box. It also had an external 8" floppy disk drive as well as a serial port for connecting to the VAX. Unfortunately, it did not have a full featured editor/assembler. Editing/assembling/linking was originally done on the department's PDP11 Model 20s which placed the output file on an 8" floppy, which could then be loaded by the Blue Box. > Later, when we got the first VAX, the Blue Box could be used as a terminal and the VAX was used to edit, assemble and link the program, and the output could be downloaded into the Blue Box/White Box.

ilaksh 9y ago

This is a starting point https://github.com/mamedev/mame/blob/master/src/mame/drivers/tempest.cpp https://github.com/mamedev/mame/blob/master/src/mame/drivers...

kabdib 9y ago

Games were cross-assembled on a VAX (using a modified version of the DEC macro assembler). I never saw the "blue FORTH box" but it was probably a ROM emulator of some kind that you downloaded code to, with some FORTH words for doing low-level stuff like debugging, resetting the target and diagnostics. The game itself was not written in FORTH. I'd forgotten that some programmers depended on other people keyboarding their source code. I think this was largely a coin-op thing; the other engineering departments never practiced that.