From: "Mark Usher" Newsgroups: comp.os.msdos.djgpp Subject: Can't get my IRQ 7 handler to trigger Date: Sun, 13 Jun 1999 12:21:50 +0200 Organization: Telenor magnet GmbH Lines: 125 Message-ID: <7k0143$prv$1@orudios.magnet.at> NNTP-Posting-Host: n095p022.dipool.highway.telekom.at X-Trace: orudios.magnet.at 929269699 26495 195.3.75.214 (13 Jun 1999 10:28:19 GMT) X-Complaints-To: abuse AT magnet DOT at NNTP-Posting-Date: 13 Jun 1999 10:28:19 GMT X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Hi I have been trying for about a week now to get my IRQ handler to trigger on a hardware IRQ 7 which is triggered by an ISA card. I've been using the examples provided by A. Williams. My timer INT routine is working great but I can't seem to get this 2nd handler working. I am 95% certain that the card is firing the interrupt, and know it works with the original software so the hardware is functioning as it should. The code is as follows....If anyone could spare a few moments to try and help me I'd really appreciate it. Mark marku AT magnet DOT at #define MASTER_FIRST_VECTOR 0x08 #define CARD_INTERRUPT 0x07 /////////////////////////////////////////////////////////////////////// // Main program init and loop int main() { _go32_dpmi_seginfo old_card_handler, new_card_handler; /* get the current handler saving it in old_handler for later */ _go32_dpmi_get_protected_mode_interrupt_vector( MASTER_FIRST_VECTOR + CARD_INTERRUPT, &old_card_handler); /* lock function so it is not paged out */ _go32_dpmi_lock_code(card_handler, (long)end_card_handler - (long)card_handler); /* get the address of the function to execute when the card INT occurs */ new_card_handler.pm_offset = (int)card_handler; new_card_handler.pm_selector = _go32_my_cs(); /* add handler to the chain */ _go32_dpmi_chain_protected_mode_interrupt_vector( MASTER_FIRST_VECTOR + CARD_INTERRUPT, &new_card_handler); InstallInterrupt(); enable(); do {} while (0==0); /* Remove the IRQ event from the chain */ _go32_dpmi_set_protected_mode_interrupt_vector(MASTER_FIRST_VECTOR + CARD_INTERRUPT, &old_card_handler); /* Flag the interrupt in the PIC as no longer being used */ handle =inportb(0x21); handle = handle & (0x1 << CARD_INTERRUPT); /* Set the mask for the PIC command */ outportb(0x21, handle); } /////////////////////////////////////////////////////////////////////// // Handler routine void card_handler() { ScreenPutChar(65, (BLUE << 4) | WHITE, 78, 6); } void end_card_handler(){} /////////////////////////////////////////////////////////////////////// // Set up the pic byte InstallInterrupt(void) { byte value; byte mask; byte i; mask = 0x01 << CARD_INTERRUPT; /* test to see if the interrupt is in use */ asm ("cli"); value = CARD_INTERRUPT | SPECIFIC_EOI; outportb(0x20, value); /* OCW 2 */ i=0; do { /* Select IRR Interrupt Request Register */ outportb(0x20, 0x0A); /* OCW 3 */ i++; value = inportb(0x20) & mask; } while ((i<255) && (value ==0)); if (i>=255) { printf("Interrupt already in use. 0x%X\n",value); return -1; } value = CARD_INTERRUPT | SPECIFIC_EOI; outportb(0x20, value); /* OCW 2 */ /* enable the cards interrupt */ value = inportb(0x21); value = value & ~(0x1 << CARD_INTERRUPT); /* Set the mask for the PIC command */ outportb(0x21, value); asm("sti"); return 0; }