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Re: OPL3LPT : OPL3 FM Synthesis on parallel port

in Marvin \ Sound
Artigkar wrote: Yet somehow the driver for OPL3LPT is not working with adlib, dunno what the issue is here. Any ideas? This was discussed in OPL2LPT thread. In order to not break many games, driver introduces artificial delays that are often too excessive for some of these games.

Re: FMonster, the monster of sound synth

in Marvin \ Sound
Tandy PSG, CMS, SSI, 8-bit DAC do not have ANY filtering at the output at all! And all those can produce very high harmonics (with square waveforms). Problems will start as soon as the signal goes to less-than-perfect ADC. Probably ok if goes to dumb amp with analog timbre block that does the job …

Re: OPL2LPT

in Marvin \ Sound
sayjionix wrote: Unfortunately, the SX-25 BIOS doesn't let me change much settings OPL2LPT uses standard LPT port mode (not bi-dir/EPP/ECP), but the problem is probably caused by notebook outputting 3.3 V levels on LPT. Using lower resistor values (2 long yellow things) could possibly help here.

Re: FMonster, the monster of FM synth

in Marvin \ Sound
So if you were to put an IMFC ROM into an FB-01, best-case it will only work via SysEx commands, and the front panel is dead. Worst case, it will crash. Then I'll just insert the old ROM. FB-01 are cheap anyway. And, if the code is for Z80, not too hard to analyse and compare (but easier to just …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
The SysEx commands of the IMFC and FB-01 are 99% the same. The IMFC has a newer version of the firmware, and supports a few SysEx commands that the FB-01 does not (my SoftIMFC and DOSBox emulation code translate these commands on-the-fly to be 100% compatible with an FB-01 attached). The main …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
Namely, the IMFC is basically the same thing as a Roland LAPC-I card: it's a MIDI interface with a MIDI module connected to it. The YM2164 cannot be accessed directly by the host. It contains a Z80 processor and its own firmware, and is basically a Yamaha FB-01 module. The only way to access it is …

Re: OPL2LPT

in Marvin \ Sound
Fancied a bit of DOS action tonight as I have finally acquired a CRT, but couldn't get Descent to work with this - is that too modern a game? Cheers, Steve Games like Descent require patching instead of TSR utility. Once patching is done, modified executable will work with OPL2LPT without any …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
Well, all other chips from the 8-bit era use the simple 'tie up the bus until all processing is done' approach. That seems to be the cheapest/simplest way to do it. Yamaha chose a more complicated way to do things: latch input internally, and release the bus as soon as possible. Sorry, but neither …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
Even on an 8088 at 4.77 MHz, an IO cycle is 4 CPU cycles, so that means that you are wasting 140 CPU cycles for every data write. That would be more than enough to 'camouflage' the overhead of a timer interrupt. My opinion is still that Yamaha designed the bus interface once, as cheap/simple/arch. …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
Maybe it can be solved with some delay circuit as it's done on SSI-2001, where number of 74HC74 use ISA IO_RDY line to manage transfers to SID. But is it worth the effort to implement something like this? I think that it was a deliberate choice of Yamaha to decouple the writing of registers from …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
If anybody has any useful information about OPL2/OPL3 - please post it! I'm still in process of researching. I did a significant amount of research (but too little actual work :( ) but not sure about what else you may want to know. I can say that if you don't "unlock" OPL3 functionality by setting …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
I haven't owned a Creative card in a long time, but I was sure some games with more generic OPL3 support detected it at 388H, and still had it work, though my memory isn't perfect. People say OPL3 works on 388-38B range on most Creative cards and (probably)all clones even if technically Creative …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
Ok, here's my 2 cents about the terminology. Yamaha OPL chips are FM, because they are digital chips supporting generation of sounds with complex spectrum by using several "algorithms" for modulating frequency/phase of one generated sound wave with another. Being completely digital, they don't have …

Re: FMonster, the monster of FM synth

in Marvin \ Sound
OPL3 is designed to emulate 2 OPL2 chips. There are minor differences, but I'd be surprised if these differences were noticeable in any actual game. OPL3 has much lower access delays, clocked @4x speed, and has MSB flipped in its DAC output format, so OPL2 DAC (3014) is not compatible with it, but …

Re: OPL3LPT : OPL3 FM Synthesis on parallel port

in Marvin \ Sound
I am extensively testing boards right now. They all look perfectly soldered, but about 50% of the boards don't work, and I think it is due to the YAC512 DAC chips. :depressed: Sad. Apparently they are not even testing these before selling. Maybe you should 1st check if clock on the pin 24 is OK. I …

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