Gigatron Hackers

It is shorter but less effective. You're right! I tried to be too smart when sampling addresses in a single 16 bits quantity. This new version is almost like your code except for using SYS_Random to shuffle the entropy on each try. That cost me five bytes to setup. Somehow I save two bytes in the f...

A different effect, without scroll, 88 bytes. maze2.gcl maze2.gt1 gcl0x $78f8 mask= [do \SYS_Random_34 _sysFn= [do [do 34!! mask& _sysArgs4= \sysArgs4, 160- if>=0loop] \sysArgs5, 8- if<0loop ] 1 x= 34!! [if<0 -1 x= _sysArgs4 7+ _sysArgs4=] \SYS_VDrawBits_134 _sysFn= $3f00 _sysArgs0= 1 [do \sysAr...

Lots of neat tricks in Phibrizzo's code.

GCL version of the same. ROMv5a and above only because it uses opcode CALLI. Only 188 bytes. I don't think GLCC will ever match this. maze.gcl maze.gt1 gcl0x 160 addr= [do <addr, 160- [if=0 \scroll!] \SYS_Random_34 _sysFn= 34!! [if<0 \print_fslash! else \print_bslash!] loop] { Print a forward slash ...

This one prints slashes/backslashes in 8x8 squares, avoiding the console and the default font. Writing the same in GCL or GASM would probably cut the gt1 size by a factor of two or so. Compile with glcc -map=32k -rom=v5a TSTmaze.c -o TSTmaze.gt1 --no-runtime-bss-initialization TSTmaze.gt1 TSTmaze.c ...

Very intresting results. Thanks for job you have done. Is the DEV7 ROM and DEV ROM same? They're different: DEVROM in https://github.com/kervinck/gigatron-rom is functionally identical to ROMv6. DEV7ROM is in https://github.com/lb3361/gigatron-rom as a dozen commits ahead of DEVROM. The main versio...

A tour de force!

Shaving cycles. Maybe inspired by Hans61 who solders for relaxation, I spend time here and there shaving cycles in dev7 rom, sometimes taking advantage of more rom code to speedup instructions (e.g. Bcc/ADDI/SUBI), sometimes tweaking the contents of the vCPU page, page 3, to recover some of the cycl...

If you want to emulate the Gigatron hardware, you have to be thoroughly familiar with the schematics and the native opcode table. If you want to emulate the Gigatron vCPU, you similarly need to be thoroughly familiar with the native code contained in the Gigatron ROM (minus maybe v6502). So my sugge...

Makes me think of “luggable” computers such as
https://en.wikipedia.org/wiki/Osborne_1