On Wed, Jan 25, 2012 at 11:28:42AM -0500, Steve Gray wrote: > 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 ;-) Yes, you've just figure out some parts of my plan :) To be honest, I haven't known anything about this cartridge. I was just thinking that TFE, RR-Net ethernet solutions are so expensive, when you have tons of unused ISA cards in your drawer with much more power, how unfair life is :) So originally I thought about some ISA "bridge" between an ISA card and a the C64. It was my wild idea to start with AdLib, since it's a simple enough card to do this (so not just the chip: the card), or even some 8 bit SoundBlaster, which also have the OPL2 chip on-board, and still 8 bit card, so it's possible to play AdLib music on C64. Then two suprises I experienced with (while google'ing a bit): 1. SFX cartridge exits, I've never heard about it before! With the chip upgrade it almost the same as you would say: "I have AdLib for C64!". 2. Interfacing with an AdLib _card_ is also not too hard: http://www.raphnet.net/electronique/adlib/adlib_en.php It's a PC paralell port solution, but the difference is minimal. If you map the needed address between C64 (to be compatible with SFX cartridge) and the AdLib card (388/389 hex) then you can even use an unmodified AdLib card as SFX cartridge (maybe even 8 bit SoundBlasters with a bit more I/O space usage you can address its DSP features etc which is rather cool to play with, I think) So just after these happened I decided to write some code for C64, as I already wrote AdLib S3M player for x86/DOS/assembly many years ago, and it felt nostalgic :) > > Steve > > > On Jan 25, 2012, at 9:58 AM, Gábor Lénárt <email@example.com> 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 list Message was sent through the cbm-hackers mailing listReceived on 2012-01-25 20:07:30
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