leeda@frith.egr.msu.edu (Dae Hee Lee) (03/25/91)
Could you help me looking for 21h and 64h port bit format for ibm pc? Where can I find the documentation on this? Thank you for your help! Daehee Lee
cur022%cluster@ukc.ac.uk (Bob Eager) (03/27/91)
In article <1991Mar25.055908.2257@msuinfo.cl.msu.edu>, leeda@frith.egr.msu.edu (Dae Hee Lee) writes: > Could you help me looking for 21h and 64h port bit format for ibm pc? > Where can I find the documentation on this? For the 21H port, look in any Intel parts book under interrupt controllers (8259). The port is a mask (called OCW1) to enable/disable interrupts on the eight IRQ lines - the bit is set to one to disable interrupts. I don't recall offhand what 64H does - it is connected to a programmable peripheral controller, which sends various bits of various ports to different places. The IBM PC Technical Reference will say. I am not near my copy at present, but get back to me if no-one else replies. -------------------------+------------------------------------------------- Bob Eager | University of Kent at Canterbury | +44 227 764000 ext 7589 -------------------------+-------------------------------------------------