In message Mon, 26 Aug 1996 20:55:04 -0700, fabio santos <[EMAIL PROTECTED]> writes: > Hi everyboby!!! > > I'm a MSX-Freak from BRAZIL... > > i have a question for you fellas: > > a long,long time ago,i was trying to do a independent disk acess on my > MSX(1.1),it means WITHOUT BIOS...but i didn't find any information about > &hD0~&Hd7 ports,that control the disk-drive... > SO,with the internet i think that you'll help me > PLEASE WHO HAS THIS INFORMATION????? > i've been looking for years... > THANKS and enjoy the best computer in the world !!!!MSX(MicroSoft > eXtended ==>i can't believe) > FABIO > [EMAIL PROTECTED] > It's correct that those I/O ports have been reserved for Floppy Disk Controllers. The standard says that the I/O ports must ONLY be enabled by the BIOS related to each seperate FDC cartridge so that there can be more cartridges using the same I/O ports. That mechanism must be Memorymapped. Using I/O ports are considered cheaper because you only need/use 8bit for the address, compared with 16bit (or 14) when using memorymapped I/O. There are really no standard for how the ports should be configured or which FDC chip to use etc. That's the task of the DISK BIOS in each cartridge. I think there are a SCSI interface also using those ports by the way but I have never been able to test it and I don't know if it follow the MSX specifications about being able to disable itself. The Turbo R FDC is compatible with the original IBM PC FDC. Except that it doesn't have the secret commands which makes it possible to make raw diskcopies. Only the first FDC's on the PC had those secret commands. Newer chips doesn't. Henrik Gilvad <[EMAIL PROTECTED]>
