New RAMDAC is now on its way. Actually I found a whole ISA card based on WD90C30-LR controller. It is very good, actually. And not only that, this card has RAMDAC already on a socket so it makes things a lot easier.
What makes the WD90C30 so good? It is fast and has good compatibility but most importantly, I already have one card based on that controller and it is the fastest card I've found for my 286. Yes, the one I have has 286 compatible BIOS. Most better ISA graphics cards have a BIOS that uses 386 instructions to rule out 286 systems. Second best VGA card I've tested on my 286 is the Ati VGA Stereo F/X, but it has worse VGA compatibility and it is slower.
That is not all, the card I have has Samsung RAMDAC but on a DIP package so I cannot test it on Copam. The new card has the very same Samsung RAMDAC but on a PLCC package that fits in Copam. I can also easily test if the Bt actually works better on a ISA card. I took a look at the Samsung datasheet and it should be snow free (and I don't remember seeing any issues on my 286) but if for some reason the Samsung RAMDAC does not work on a Copam, then at least I have and excellent spare card for my 286. I'm going to test the card on a Copam as well since I'm interested to see how it compares to the S3 928 I already tested. I'm going to test Cirrus GD5426 as well for even more comparison.
I was actually testing something else when those Bt issues came too noticable. I was testing if General Midi card is needed. Since this system is for games before Doom and CD-ROM-era I was under the impression that there are not many General Midi games but a lot of MT-32 games. That was the case. If General Midi was supported, MT-32 was also. And many games expected the General Midi device to use port 330 and that is the same where MT-32 should go. So even though Orpheus allows to use two ports, one for intelligent mode and the other for non intelligent mode (enough for General Midi devices) I would have to use the same port for both to maximize General Midi support to make the General Midi device actually useful.
Using same port for both does not matter that much. I have Roland SCC-1A on my 286 as a controller for old type MT-32. By default sound comes out from both but there is a sysex to silent the SCC-1A so only MT-32 will produce sound. And if I want sound only from SCC-1A, then I simply do not power on the MT-32. Quite simple but it would have been even simpler if two different ports could be used. Later games usually always allow to configure the midi port so for late 486 or Socket 7 systems I would have put the General Midi device to port 300 and used MT-32 with all games that require port 330.
Speaking of sysex, I wonder if it is possible to make a sysex that would only play the extra CM-32L instruments. That way the MT-32 would play whatever it plays but the GM device would play the missing instruments if game supports those. That would make the General Midi device much more useful and it would make a lot of sense to set them to same port.
But anyway, the conclusion is that I won't install any General Midi device to the Copam. It can have the old type MT-32 since I finally found LAPC-I for my 286. So the Copam will have Orpheus, GUS Classic and MT-32. What a perfect setup for a computer meant to play games before Doom and CD-ROM-era. By the way, GUS can act as a General Midi device if it turns out that some game needs it after all. I think I should write more about GUS next.