OSWORD &FC

OSWORD &FC (252) DOS CRTC Control

This OSWORD call is installed by the 80x86 DOS BIOS.

Commands are sent from the 80x86 via Tube Register 2 within the OSWORD protocol, so cannot be called through the normal OSWORD mechanism. The transaction must be done manually by the client by sending through Tube Register 2:

   &08 : Start OSWORD transaction
   &FD : OSWORD call &FD
   &00 : TxLen=0
   xxx : Send a series of commands
   &00 : RxLen=0, terminate the OSWORD call

Commands

• b7=0 : program CRTC, command specifies register, next byte sent is the CRTC data
• &FC : write to mouse port (unimplemented)
• &FD : initialise event handler
• &FE : initialise mouse driver
• &FF : finish. All other commands also finish the transaction.

See also

• OSWORD &FC source code
• OSWORDs list at mdfs.net

Tube OSWORD calls
OSWORD &FA : Data transfer across Tube OSWORD &FB : MFM floppy disk access OSWORD &FC : DOS CRTC control OSWORD &FD : DOS Text control	OSWORD &FE : DOS Hard disk access OSWORD &FE : Z80 FM floppy disk access OSWORD &FF : DOS Fast screen access OSWORD &FF : Data transfer across Tube

Jgharston 14:28, 26 May 2009 (UTC) Jgharston (talk) 10:55, 17 December 2024 (CET)