OPL2LPT

[Great Hierophant]

"A new batch, very limited edition available now.
- includes authentic legendary Yamaha OPL2 chips.

I believe that calling these chips as "authentic" chips may be a bit of a stretch. For the reasons given at the end of this blog post, http://nerdlypleasures.blogspot.com/201 ... ation.html, I believe these could be remarked clone chips, used pulls or factory rejects.

[jaZz_KCS]

"A new batch, very limited edition available now.
- includes authentic legendary Yamaha OPL2 chips.

I believe that calling these chips as "authentic" chips may be a bit of a stretch. For the reasons given at the end of this blog post, http://nerdlypleasures.blogspot.com/201 ... ation.html, I believe these could be remarked clone chips, used pulls or factory rejects.

As far as I know, these Yamaha chips are still being produced. The article suggests these are rebranded chips, however. Whatever the case, they are the real deal and suit our purposes well.

[jaZz_KCS]

Is that PS/2 MCA based?

I do not know. I do know that the Docking Station (more like very bulky "Service Station") connects via the ISA bus in the back providing support for up to two full length ISA cards.

[derSammler]

I believe that calling these chips as "authentic" chips may be a bit of a stretch. For the reasons given at the end of this blog post, http://nerdlypleasures.blogspot.com/201 ... ation.html, I believe these could be remarked clone chips, used pulls or factory rejects.

I only see assumptions here. Funny enough writing: "it is extremely likely that Yamaha does not make those chips anymore". Why not just ask them instead of making assumptions..?

[SteveC]

Is that PS/2 MCA based?

I do not know. I do know that the Docking Station (more like very bulky "Service Station") connects via the ISA bus in the back providing support for up to two full length ISA cards.

Ah I doubt it then if it has ISA. Thanks IBM for the PS/2 range that brought us things like PS/2 ports, 3.5" floppy drives, VGA graphics but your MCA architecture was too ahead of the time!

[elianda]

Is that PS/2 MCA based?

Yes it is a MCA machine.
It is actually this machine: http://retronn.de/imports/ibm_pc.html

[SteveC]

Oh yeah the model 80 is. I remember my dad having a model 80, and 70 and a P70 at the same time in his office at work and I believe they were all bought at the same time so were very similar specced.

[Great Hierophant]

As far as I know, these Yamaha chips are still being produced. The article suggests these are rebranded chips, however. Whatever the case, they are the real deal and suit our purposes well.

I only see assumptions here. Funny enough writing: "it is extremely likely that Yamaha does not make those chips anymore". Why not just ask them instead of making assumptions..?

And what use has a Yamaha YM3812 been put since 1991? What new product would it have been featured in for the past 25 years? Why would Yamaha continue to make the chips when it had a line of superior replacements. Even Yamaha's budget keyboards using the chip seem to have come to an end in 1991. Yamaha is not making these chips anymore and has not for a long time. Yamaha did make tens of millions of the YM3812, so it isn't a hard chip to find. Clone chips were made and may still continue to be made, and if they are die-copies of the original, then that is great. The idea that Yamaha is still making these chips defies logic and common sense.

[derSammler]

The idea that Yamaha is still making these chips defies logic and common sense.

Which won't change the fact that this is all still based on assumptions. Just remember how long Sony produced 3.5" floppy disks. There are niche markets that we don't know about. Anyway, that blog post just makes assumptions and tries to make up that these chips must be clones. Similar discussions can be seen in the Amiga community, where people try to find all kind of "evidences" why certain 680x0 CPUs are probably fake. This is all moot and often people are completely wrong, since nothing is based on facts. Always made me wonder what's the motivation behind this.

[Plasma]

The idea that Yamaha is still making these chips defies logic and common sense.

Which won't change the fact that this is all still based on assumptions. Just remember how long Sony produced 3.5" floppy disks. There are niche markets that we don't know about. Anyway, that blog post just makes assumptions and tries to make up that these chips must be clones. Similar discussions can be seen in the Amiga community, where people try to find all kind of "evidences" why certain 680x0 CPUs are probably fake. This is all moot and often people are completely wrong, since nothing is based on facts. Always made me wonder what's the motivation behind this.

Fact: YM3812 is not available from any reputable supplier (Digikey, Mouser, Jameco, etc.)
Fact: YM3812 is only available "new" from Chinese sellers on ebay and aliexpress

Do you really think Yamaha has a secret factory still producing YM3812, and for some reason are only selling them to the Chinese?

[chartreuse]

I have to say I'm quite enjoying my OPL2LPT that I got earlier this week. Was doing some testing/playing around with it on an XT clone system using software I wrote and modified to use the OPL2LPT instead of the 0x388 port. It worked on both the standard parallel port on a Hercules clone card (0x3BC), and on the port on the Multi-IO card at (0x278). Can't quite compare the sound with a proper Adlib card as I only have a SB Pro 2 (OPL3) in my XT, but the sounds are very similar, with a very good amount of punch.

I also have been doing some testing with non-PC computers, and currently got the OPL2LPT working (playing a tone) on an Epson QX-10 CP/M based system. Seems like it should be fine to connect, and write software for, on any system with a Centronics compatible printer port. The Epson uses a standard 8255 for the parallel port, and the code ended up looking remarkably similar to the x86 code for driving it. Just needed a cable adapter (comprised of a standard printer cable with the micro-ribbon end in the computer, and a gender changer on the other end) to hook up the OPL2LPT to it.

[dreamblaster]

I also have been doing some testing with non-PC computers, and currently got the OPL2LPT working (playing a tone) on an Epson QX-10 CP/M based system. Seems like it should be fine to connect, and write software for, on any system with a Centronics compatible printer port. The Epson uses a standard 8255 for the parallel port, and the code ended up looking remarkably similar to the x86 code for driving it. Just needed a cable adapter (comprised of a standard printer cable with the micro-ribbon end in the computer, and a gender changer on the other end) to hook up the OPL2LPT to it.

Very cool, if you have any video or audio recordings of the CP/M system using OPL2LPT,
I'd love to hear/see !

[chartreuse]

Very cool, if you have any video or audio recordings of the CP/M system using OPL2LPT,
I'd love to hear/see !

I'll end up making one once I've written some software to play more than just one static note, need to either find an adlib tracker format that's not very demanding (might just use Reality Adlib Tracker without effects) or just write something of my own. I'd like to get it playing some Christmas music though I haven't found any already tracked.

[Scali]

I'll end up making one once I've written some software to play more than just one static note, need to either find an adlib tracker format that's not very demanding (might just use Reality Adlib Tracker without effects) or just write something of my own. I'd like to get it playing some Christmas music though I haven't found any already tracked.

You could try VGM, it's just a list of register values and delay codes. Very simple to replay.
VGM is mainly designed for capturing music with emulators. There's a version of DOSBox that can capture AdLib VGM.

[Malvineous]

IMF also has little CPU overhead (just register writes and timing delays) and was used in many Apogee/id games so there are a number of songs in the format you can play straight out of the games' data files.

[Megadisk]

Received and put together my board over the weekend (working good tested on an IBM PS/2 L40sx laptop) . Quick question, If I were to connect a Disney Sound Source to the parallel port and then attach the OPL2LPT board, will it work?

Thanks for any reply!

[dreamblaster]

Received and put together my board over the weekend (working good tested on an IBM PS/2 L40sx laptop) . Quick question, If I were to connect a Disney Sound Source to the parallel port and then attach the OPL2LPT board, will it work?
Thanks for any reply!

I have no idea if it would work, probably not or not without side effects, as both may use the same pins for different purposes. You can try and let us know

[noop]

I proposed to patch reads from the Adlib port with reads from any other port that is not being intercepted by the driver Because most ISA reads generate roughly the same delay.

And what advantage would that have over handling the delay inside the write?

Games will be able to measure port read latency properly and the rest will work the same.

[Scali]

Games will be able to measure port read latency properly and the rest will work the same.

Not really.
The first time you still pass through the virtualization layer, with extra overhead for the patching.

Besides, how many games, if any, do even measure port latency at all?
It doesn't make sense.
The delay times are given by Yamaha: 3.3 us and 23 us respectively. Nothing to do with reads.
The port-reads are done because with a regular IO cycle, you get the correct delay with 6 and 35 reads respectively (regardless of CPU-speed). So that is what most games hard-code as delays.
If you can't assume a fixed speed for the IO cycle, then why bother doing reads anyway? You can create delay loops with any kind of instruction. Choosing reads doesn't make sense in that scenario.

[Great Hierophant]

Received and put together my board over the weekend (working good tested on an IBM PS/2 L40sx laptop) . Quick question, If I were to connect a Disney Sound Source to the parallel port and then attach the OPL2LPT board, will it work?
Thanks for any reply!

I have no idea if it would work, probably not or not without side effects, as both may use the same pins for different purposes. You can try and let us know

No, it won't work properly. The Sound Source passes through all pins except 17 through, the OPL2LPT passes none. So the Sound Source must come first in the chain.

In addition to pins 2-9 (data bus) and pins 18-25 (ground), a Disney Sound Source uses Pins 10, 16 & 17, the OPL2LPT uses pins 1 and 16. Pins 1, 16 & 17 are outputs, pin 10 is an input. The DSS turns itself on and off through 17 and pins 16 and 10 to indicate to the system when its buffer is full. The OPL2LPT uses pin 1 to determine whether the address or data register is the writable register and pin 16 for write enable. Software supporting the DSS should always set pin 16 to high when activated, which disables the write enable (active low) on the OPL2LPT chip.