Message-Id: <199602282139.VAA00404@mailbox.rmplc.co.uk> Comments: Authenticated sender is From: "Matthew Lloyd" Organization: Private To: djgpp AT delorie DOT com Date: Wed, 28 Feb 1996 21:33:21 +0000 Subject: Writing PM and RM interrupt handlers in assembler Reply-to: lloyd AT rmplc DOT co DOT uk Dear All, I'm using DJGPP v2 (very impressive it is too), and I'm converting a program which makes use of the timer interrupt and the SB interrupt. Since this program eventually will become a commercial product, I'd like to write the handlers for these interrupts in assembler (as advised in the FAQ). Are there any examples around of assembler IRQ handlers? I've seen the C examples in pctime13.zip and sb_05.zip, but I really need to use assembler. I'd be most grateful if someone could post me an example since I'm rather confused about how to: i) Load the application's data selector into DS when the interrupt procedure starts - where does the value come from? ii) Call the previous interrupt handler; should I call the old PM vector, the old RM vector, and... how? iii) Transfer data to/from the real-mode IRQ handler iv) Call the previous IRQ handler from the real-mode handler Any help is much appreciated. Thanks, Matthew Lloyd.