SA-1 Documentation

Calamity · Post by **Calamity** » Thu May 21, 2009 4:21 pm

I want to develop some code for a real SA1. Is there any documentation available? Google's not much help, and Internet Archive seems to have missed some good stuff from back in the day...

What's the best way to find out about clocks, handshaking, memory arbitration, interrupt vectors? Just troll through the ZSNES source and see how it deals with emulating it?

TIA

creaothceann · Post by **creaothceann** » Thu May 21, 2009 8:33 pm

RHDN has some info: link

kode54 · Post by **kode54** » Fri May 22, 2009 6:15 am

And if you want to troll through source code, you can also look at bsnes.

Post by **grinvader** » Fri May 22, 2009 8:57 am

*hat tip*

Couldn't have said it better.

Calamity · Post by **Calamity** » Fri May 22, 2009 9:15 am

Thanks for the tips guys. Wish I'd thought of looking in the development manual first. There's a whole section on the SA-1 right there.

From that I get the idea that the reason the SA-1 exists was to give developers an easy upgrade path when they ran out of cycles on the SNES cpu, without having to do any recoding or porting. And depending on how much effort they put in, anything from a 2-5x speed up could be instantly reaslised. How decadent to put all that CPU power in the cart!

Gil_Hamilton · Post by **Gil_Hamilton** » Fri May 22, 2009 10:08 am

Calamity wrote:How decadent to put all that CPU power in the cart!

Well, they couldn't very well redesign the SNES to have a more powerful processor.
I mean, they COULD have and launched it as a new system, but it would've been highly unsatisfactory.

The SNES was critically underpowered, and had coprocessors almost from day 1. The 65816 was a poor choice of processor, in retrospect.

Admittedly, the DSP-1 was replacing a coprocessor that was removed from the base hardware more or less at the last minute, but... Pilotwings missed the Japanese launch by exactly one month, if Wikipedia can be believed.

ikari_01 · Post by **ikari_01** » Mon Jul 06, 2009 9:39 am

Does anybody still have that document? The link is dead. Seems I missed it by a couple of days.

creaothceann · Post by **creaothceann** » Mon Jul 06, 2009 12:04 pm

The link works for me.