The schematics for the sfx sound expander are available.. If you can't buy one, maybe you could build one? I picked up an old sound blaster with ym3812 and support chip off eBay for about $12, but you could probably buy the chip(s) separately. Get an 8-bit baby prototyping cartridge board and you're good to go ;-) Steve On Jan 25, 2012, at 9:58 AM, Gábor Lénárt <lgb@lgb.hu> wrote: > Hi, > > On Wed, Jan 25, 2012 at 06:37:34AM -0800, andym00 wrote: >>> Sound Expander in WinVice 2.2 seems to work fine. >>> >>> More SFX Sound Expander stuff, cool, what are you working on Andy? >>> >> >> Ah, okay, I'll give 2.2 a go then.. Thanks.. >> >> As for what I'm working on, just really ideas at the moment.. I've always >> wanted to play with the thing and was curious if it was possible to push the >> timing requirements down a bit, or maybe use a timer based approach to avoid >> wasting loads of time waiting to send registers, or even piggy back >> register > > What do you mean? The needed time to wait before you can write a register? > With the OPL chip, you had to wait a bit after you selected the register and > before write the actual data and some wait too before you can address > another register. The needed time for this is quite low, before data/after > register select is something like four NOPs, so I wouldn't think it's worth > using timers to wait etc :) There is a bit more delay needed after writing > the data (and using another register) in my player code it's not a problem, > since it's far enough delay given by the player code itself :) > > Given by microseconds from the AdLib specification (so it's about the OPL2 - > YM3812 - chip, I am not sure the very same is true for the YM3526 which is > the one the cartridge is equipped with, however it seems some people > upgraded the chip since it's backward compatible): > > The AdLib manual gives the wait times in microseconds: three point three > (3.3) microseconds for the address, and twenty-three (23) microseconds > for the data. > > Given by the ~1MHz clock of the 6510 in C64, it's about 4 cycles to wait > after specifying the address (register selection) and 23 cycles after the > data. I am not sure why it's told (by more clever people than me) that 4 > NOPs is needed, as AFAIK a NOP lasts for 2 cycles, but there must be some > reason ... > > Or did you think about the timing needed for playing, not the individual > register access delays? > >> sends on the back of sprite multiplexer interrupts.. Really just experiments >> and with it in mind that I'd love to be able to use it for in-game music, if >> it doesn't prove too costly.. Its always bugged me that no game has ever >> supported the Sound Expander, yet :) > > I'm playing with the idea to write an S3M player (to be precise: S3M files > using only AdLib instruments, not digital samples), and a converter too > which "stripes down" the S3M for a more simple entity in sequence of BYTE > pseudo-ops in assembly source form, so it can be reused for an in-game > player engine which can be much more trivial than a fully-capable S3M player > with its complexity, and can be done in an IRQ routine or so ... > > Still, I lost the interest a bit currently, since it's so sad that I haven't > got a real cartridge, it's not so fun to do it in an emulator only. > Currently only my DRO player work (however I have my IMF->DRO converter > now). > > >> >> -- >> View this message in context: http://nabble-com-cbm-hackers.2304266.n4.nabble.com/SFX-Expander-programming-and-VICE-tp4107070p4327376.html >> Sent from the Nabble.com: cbm-hackers mailing list archive at Nabble.com. >> >> Message was sent through the cbm-hackers mailing list > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2012-01-25 18:00:09
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