Re: PSG bit resolution (was Re: ReadWav for MSX)
jam wrote: > > Hi, Ricardo!! > > RL> Some Sega Master System games do use the 5.5 bits trick, but the > RL> PSG of the Master isn't a true AY-3-8190. Instead, it is a > > :? It sounds strange to me. I've got a Master System and I've seen a fantastic > AY-3-8910 inside. The sega master system has a chip wich looks like the V9938 It's the VDP and is clocked at 10mhz ... Inside it has also the PSG. There may be out other versions of the Hardware ... but the one I meant has only 2 dedicated (SEGA) ICs one is the VDP/PSG and other is the I/O chip. All the rest is 3 16kb pseudo SRAM chips (2 for vram and one for the Z80) And the Z80 iself. > RL> SN-something, slower than our one (and also it doesn't have > RL> envelopes...) > > H. I think you mean the SN76489A PSG. It's the ColecoVision one :) The model wich has the PSG inside the VDP uses this TEXAS INSTRUMENTS PSG ... then it's probably that or you have a "pirate" Master system or it isn't a master system or even it's a master system but is of a diferent hardware version ... Cya MSXers ... =) MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
PSG bit resolution (was Re: ReadWav for MSX)
Hi, Ricardo!! RL> Some Sega Master System games do use the 5.5 bits trick, but the RL> PSG of the Master isn't a true AY-3-8190. Instead, it is a :? It sounds strange to me. I've got a Master System and I've seen a fantastic AY-3-8910 inside. RL> SN-something, slower than our one (and also it doesn't have RL> envelopes...) H. I think you mean the SN76489A PSG. It's the ColecoVision one :) JAM ([EMAIL PROTECTED]) *MSX Dreams* ... [David Burton] Direct descendant of James. MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: PSG bit resolution (was Re: ReadWav for MSX)
On Thu, 27 May 1999, MkII wrote: > 4 sound sources and you got only 4 bits??? AFAIK each PSG channel has a 4 > bit volume resolution (16 levels), so 3 channels yield 5.5 bit (16*3=48 > levels). As level 16 is reserved for EG and level 0 for mute there're > actually 45 levels. > I tried to use this 5.5 bits trick when making MUST. Unfortunately, there's no way to change all 3 volumes at the same time, and even the small delay of 12 clock cycles introduced by consecutive OUTs degrade the sound... The keyboard click cannot be used together with PSG due to the same reason. Some Sega Master System games do use the 5.5 bits trick, but the PSG of the Master isn't a true AY-3-8190. Instead, it is a SN-something, slower than our one (and also it doesn't have envelopes...) Ricardo Bittencourt http://www.lsi.usp.br/~ricardo [EMAIL PROTECTED] "Ricardo is subtle, but malicious he is not" MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
PSG bit resolution (was Re: ReadWav for MSX)
> It uses the feature of PSG what allows you to set period 0 to the >channels and >change only their volumes to use the PSG as a D/A converter. And plus the PPI >bit used to generate the keyboard click. So we have 4 bits... 4 sound sources and you got only 4 bits??? AFAIK each PSG channel has a 4 bit volume resolution (16 levels), so 3 channels yield 5.5 bit (16*3=48 levels). As level 16 is reserved for EG and level 0 for mute there're actually 45 levels. Dunno the actual loudness of the software sound (key click) but I really doubt it could be usable as an additional bit. Too much of a coincidence if it was as loud as the 3 PSG channels at max volume. Who knows... Yeah, that's it: WHO KNOWS? TELL US. Kiss you lot. -- Madonna Mark Two "Martin Galway means to me what Elvis meant to Sigue Sigue Sputnik" MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
