Mini-memory and opcodes

[palmheads]

Was reading about a guy here in New Zealand in the mid 80's who was writing extremely high quality machine code games for the Sega SC3000 & selling them. A Z80 based machine very similiar to MSX (used TMS9929A VDP), but with the similar TI sound chip as the TI-99/4a (SN-76596). So I guess similar to the Colecovision. Have played some of these games, and they are REALLY good. Like Jet Set Willy quality.

http://playitagainproject.org/creators/michael-boyd-2/

http://playitagainproject.org/wp-content/uploads/MichaelBoydInterview.pdf

So e would have been using long REM statement at the start of his code, then POKEING in Z80 opcodes through DATA statements or though some sort of BASIC loader. Incidently I had a go at this a few years ago for the ZX81 with a "Hello World" example using 3 different methods (keying in opcodes thru a loader, then writing assember on the ZX81 using an assembler from the time, lastly using "pasmo" an assembler on a PC compiling a loadable executable):

http://www.sinclairzxworld.com/viewtopic.php?f=6&t=1050

That was quite fun getting it working.

But essentially the guy above for the Sega SC3000 was figuring out the Z80 opcodes on paper, then entering them in some way without using an assembler at all. Saving his work to cassette tape. Incidently the same guy wrote an assembler/disassembler for the Sega but never actually used it himself (SegaMon).

Was thinking about the mini memory module (and particulary EasyBug) for the TI-99/4a. The combo of the Line By Line Assembler actually made it quite a powerful dev environment at the time. You'd figure out stuff on paper. Use the LBLA to write assembler for small routines & get instant compile/feedback of the opcode and mem location. Then you could use EasyBug to key in the opcode to the right mem location. Or use CALL PEEK/POKE from TI BASIC etc.

Sure its way more cumbersome thatn the Editor-Assembler. But looking back, EA actually might have spoiled developers a bit, as alot of systems didn't really have those tools!

Dunno why I have a "thing" for the mini memory module! Something about it I find intriguing.

Ah the good old days!

Daryn