I've compared the two and I think they're different. The PS/1 driver (for PoP2 at least) uses what looks like a FIFO, rather than DMA. It does trigger IRQ7 and the interrupt handler reads some status bits and feeds more to the FIFO (via an OUTSB). It also uses ( 1,000,000 / HZ ) - 1 for calculating …

Well, just judging by ear, the KQ5 music sounds the same in Tandy and PS/1 mode. You don't think that IBM had a load of old PCjr parts lying around that they had to get rid of? :wink: The version of KQ5 I have doesn't seem to support samples, so I'm still looking at PoP2 to try and figure out the " …

Wizball should have a bit of PC speaker sampled audio in it, according to this: http://www.oldskool.org/sound/pc Here is the routine which might be trying to do it. It is using a PIT mode which has not been added into the emulation - the Hardware Retriggerable One Shot. 0F63:4463 "routine". DI = 09 …

I didn't know this existed, but Mobygames says it does... very hard to find any information on it. Sure enough, my old KQ5 EGA supports it. According to this: http://www.old-computers.com/museum/doc.asp?c=1274&st=1 The Audio card, which fits into the system unit, includes the following: · 3 voice …

Oops, didn't read all the way through that one. 😊 But, at least we know that it happens on non-Amstrad systems as well.

Aha... according to this list: http://bochs.sourceforge.net/techspec/PORTS.LST There are indeed mirrored ports at 03D0!

I decided to have a peek at Prohibition and it appears to be writing to the CRTC at 0x3d0 and 0x3d1 to do the "scrolling" (writes to regs C and D to set the start address). I tried compiling with the crtc ports mirrored at 0x3d0/0x3d1 (VGA_SetupOther) and the game does seem to work. I don't know how …

Thanks for the games and the link to PCem! I've emailed the author to see if he knows of any. Here is the current list of PC1512 video mode software: Apps: * Dpaint. * GEM. Games: * Feud. * Maupiti Island. * Dragonfly. * Flags.

I did a bit of digging into why this didn't work... First of all, it has a few instances of instruction 0xFFFF in the code, which triggers the fatal "illegal GRP5:7" error. Ignoring it isn't enough, as the whole thing runs amazingly slowly (as previously reported). The solution is just to trigger an …

Hi, I've got the DOSBox source compiling in VS2003 and I'm trying to add the Amstrad PC1512's special 640*200*16 colour mode (their own extension to CGA). That's what the mysterious INT 15h AH=06h is for - detecting the PC1512. I've got it partially working, but I've not had much luck with …