This week, critor discovered documentation for ASM programming on Toshiba T4x processors, used in all recent TI scientific calculators, such as the TI-30XB/XS MultiView, TI-30X Pro MultiView, TI-34 MultiView, TI-36X Pro and TI-Collège Plus. This is a huge step towards ASM programming on these calcs. Next step is to find the necessary tools to compile ASM code described in the above documentation, which are currently nowhere to be found, and to find a way to execute the resulting programs.

Knowing that these calculators have a dot-matrix screen similar to their graphic counterparts, TI-30 programming will allow infinite possibilities, much like the TI-83+, but with a 2x smaller screen.

Click here for more info, including links to the documentation, emulators and ROMs.

Next step is to find the necessary tools to compile ASM code described in the above documentation, which are currently nowhere to be found

Don't count your chickens before they hatch . This is not a problem since we already have documentation on all of the opcodes and can make our own programs. The real problem is that these calculators don't execute from ram, they only execute from rom. Which means that even if we do manage to type a program into these calculators and find a glitch to jump to a random spot in the OS, we have no way to run these programs.

The OS is at address 0000h and goes to FFFFh. Ram starts at 00h and goes to FFh on 4 separate banks. As you can see, ram on rom are completely different.

The only hope is in a ram area called DRM, it is really hard to access, but is much bigger. Our only chance of perhaps getting asm running is if this area is mapped to C000h-FFFFh or similar, however, this is extremely unlikely and the emulator that goplat disassembled did not show anything even remotely like that.


However, if anyone is interested, I can send you a disassembly of whatever OS you want. (Well, of course I would never actually send it, that would be illegal  , confusing...)

You could post your disassembler, that would definitely be legal

Yeah, indeed it would be.


Have fun finding your own roms

It was still a cool idea nonetheless, and a good learning experience! =)

Too bad.
But I agree, it was still interesting and we did learn about another (admittedly, rather worthless, but who cares?) ISA.

Hey yo,

Just wanted to know if there were any updates on this topic.

Thanks,
ALIYSS

It's been 6 and a half years since the previous post. I think it's safe to assume that there are no more updates.