hennesse@dtrc.dt.navy.mil (Hennessey) (12/27/89)
I have a interrupt-driven serial port driver that works fine on the PC, but does not work on an AT. It seems that some interrupt occurs, and the controller is not reset, causing a lack of interrupts. If I remember correctly, the AT computer uses 2 8259A interrupt controllers., instead of one like the PC. I need programming details: Where is the second chip (I/O addresses A0 and A1???) What does the second chip service? How do you set the interrupt mask register (I/O port 21 on the PC) How do you reset after servicing the interrupt? Thanks... Dave (301) 227-1400