Hi, A while ago I got one of these off a friend of a friend and got it going a few days ago. I was wondering if anyone had any information about it, specifically a technical reference manual. I'd like to have a closer look at its architecture, just out of curiocity and for this... The hard disk interface is a WD33C93 and has a BIOS to let MS-DOS access it. It currently has its original 20MB Miniscribe hard drive internally and I attached an external 140MB 5.25" SCSI drive. Just as an experiment, I attached a CD-ROM drive to it and set the number of SCSI drives to three. It detected the CD-ROM drive when there was a disk in it, but MS-DOS doesn't natively support ISO9660 drives. So I made a 20MB hard disk image in QEMU, partitioned it in FDISK and formatted it, then burnt the image to a CD. MS-DOS detected it as a drive first go. This shouldn't be a surprise if you know a thing or two about the SCSI architecture. This makes me wonder if there's such thing as an ISO9660 extension for MS-DOS that will let me access CD's in this way. The issue is if I don't have a disc in the CD-ROM drive when it boots it will fail to detect the drive. The other option is writing a driver for the WD33C93... Thanks, Alexis