23-Nov-86 17:51:46-MST,1633;000000000000 Return-Path: Received: from apg-1.arpa by SIMTEL20.ARPA with TCP; Sun 23 Nov 86 17:51:31-MST Date: Sun, 23 Nov 86 19:46:58 EST From: Robert Bloom AMSTE-TEI 3775 Subject: Interrupts on the N* Advantage To: info-cpm@amsaa.arpa, info-micro@simtel20.arpa, northstar-users@simtel20.arpa Cc: rbloom@apg-1.arpa Help. I find I have to write an interrupt-driven application for the NorthStar Advantage. Unfortunately, I don't know how. Specifically, I do know how to enable the interrupts, and write the interrupt handler, but actually what happens at interrupt time eludes me. At the interrupt, the z80 jumps to the interrupt routine. Where? My z80 book says, "the z80 expects an [RST or CALL] instruction to be placed on its data buss [by the interrupting device]" how it do dat? Two people who I asked said "to where you program it to" but I have no idea how to do that. I have a Advantage technical manual. It may have the info I need but I find it incomprehensible. (I gather that interrupt routines are strongly hardware-dependant.) And I do understand that the Advantage is not very fast, but can't believe a simple get-and-put routine with interrupts wouldn't be fast enough for 4800 baud. So, can someone help me out? I'm trying to store the input characters from the SIO card away till they can be processed. I have DTR control on the port but I haven't been able to get that to work. (I'm trying to write a very simple high-speed commo program.) I really need a low-level example. bob bloom