Quote:

---

The model1 games include somewhere on the board a pair of dsps called TGPs, or MB86233. One is used for T&L, one is used for generalized math operations. The same structure exists in model 2a. The T&L program happens not to be a problem, we're experienced enough to be able to guess what it does and it doesn't seem to change per-game. The math dsp program changes per-game.

In the case of 2a, the math dsp program is uploaded by the main program. From there we've been able to understand how the dsp itself works (it's essentially undocumented otherwise). That made 2a working, and we found out that virtua racing expects essentially the same program than daytona usa.

For the other three games, otoh, we don't have the program. Nobody has even been able to find where in the pcb it is hiding, making decapping a chancy proposition. What is currently working in mame is the result of complete guesswork, see src/machine/model1.c. So if you want to see swa working, you need to continue the guesswork.

Some hints I can give:

- the understanding of the dsp and the use of the daytona program for vr happened *after* the guesswork happened. That means there may be clues about what the functions are supposed to do in the 2a programs
- there is a tgp-accessible rom that the program does lookups into. It was hooked up in vr before the daytona use (the track_* functions). It was not hooked up in swa/wingwar in no small part because someone has to find out which function is supposed to do the lookup in the first place. Only hint I have: acc_seti is probably track_select swa version in reality (which won't change much, there's only one "track" in swa, the parameter is always 0).

---