Gb émulator for Ti 89! port possible ?

bastien · Post by **bastien** » Sun Sep 05, 2010 4:20 pm

Hi,
i found this émulator for Ti-89:
http://www.ticalc.org/archives/files/fi ... 36950.html

this calculator have a 68K just like the Sega Genesis do you think it's possible to port it ?

because the émulation looks like impressive

thanks

Shiru · Post by **Shiru** » Sun Sep 05, 2010 4:25 pm

68K at 10-16 MHz, with twice more RAM, with different type of video hardware (don't know details, but not tile-based).

Zerosquare · Post by **Zerosquare** » Sun Sep 05, 2010 4:48 pm

Hi,

Here are a few facts about the TI-89 :

The display is just a 1-bit framebuffer with zero extra hardware support (no tiles, no sprites). Grey levels are simulated by swapping images quickly ; it works because the LCD is a (crappy) passive matrix one.

The RAM is indeed larger, but it's not entirely available to programs ; part of it are used by the OS and other installed programs / variable. I don't know how much the emulator actually uses.

I'm neither a TI-89 programmer nor a Megadrive one, but I think it may not be impossible to port this emulator, since parts of it could be rewritten to take advantage of the hardware.

Chilly Willy · Post by **Chilly Willy** » Sun Sep 05, 2010 5:21 pm

Looks interesting. The core is assembly, which should help the speed.

tails92 · Post by **tails92** » Mon Sep 06, 2010 2:33 pm

I think that the core is usable, but the video subsystem will have to be redone from scratch, by using the Megadrive's capabilities directly (like tiles and sprites, which are not supported by the Ti89, which, as someone already pointed out, uses a framebuffer). Just like when I did my "NES emulator" for the Megadrive.

Christuserloeser · Post by **Christuserloeser** » Mon Sep 13, 2010 1:31 pm

VERY nice find !

bastien · Post by **bastien** » Tue Sep 14, 2010 3:58 pm

Christuserloeser wrote:VERY nice find !

thanks !
you want to make something ?

TmEE co.(TM) · Post by **TmEE co.(TM)** » Tue Sep 14, 2010 8:38 pm

It should not be too hard to port to MD, the input and GFX stuff has to be completely reworked but all else should stay mostly same. I don't think the emu is doing self modification... but if it does then it complicates matters (got to do RAM juggling there...).

Most stuff could run straight out of ROM so storage should be an issue at all.

Pushing GFX tasks to VDP should make things fair bit faster

bastien · Post by **bastien** » Wed Sep 15, 2010 6:58 am

yes, i really hope one of you make this port