braun@m10ux.UUCP (MHx7079 mh) (06/08/87)
I plugged an Ampex Megastore host adapter card into a PC 6300. This board is mostly latches and gates, and 4k of ROM, located at C800:0000. When the machine is booted, the diagnostics recognize the existance of the ROM, and apparently call some initialization code on it (which announces an error, but that's another story). I am trying to disassemble/debug the code in this ROM, and I need to know: How does the system recognize the existance of the ROM? I have already heard of (and verified) the ROM checksum. What format does the ROM have so the system can call initialization code on it? I assume the purpose of this code is to initialize the card and then overlay some interrupt vectors for hard disk I/O. What is the BIOS support for hard disks? (I have DOS 2.11) This board is part of a hard disk system, but it does not at all resemble the standard IBM controller. What interrupts relate to hard disks? What is a good book for arcane hardware questions like these? I remain, etc., -- Doug Braun AT+T Bell Labs, Murray Hill, NJ m10ux!braun 201 582-7039