User`s manual

Chapter 3 Hardware Description
TI6VGA User’s Manual 9
3.8 Interrupt Request (IRQ) Lines
There is a total of 15 IRQ lines available on the motherboard. Peripheral
devices use an interrupt request to notify the CPU for the service
required. The following table shows the IRQ lines used by the devices on
the motherboard:
Level Function
IRQ0 System Timer Output
IRQ1 Keyboard
IRQ2 Interrupt Cascade
IRQ8 Real Time Clock
IRQ9 Software Redirected to Int 0Ah
IRQ10 Reserved
IRQ11 Reserved
IRQ12 Reserved
IRQ13 Co-Processor
IRQ14 Primary IDE
IRQ15 Secondary IDE
IRQ3 INTERRUPT
IRQ4 Serial Port #1
IRQ5 INTERRUPT
IRQ6 Floppy Disk Controller
IRQ7 Parallel Port #1
3.9 Onboard PCI-IDE
The PCI-IDE controller, 82596 chip, supports PIO mode 3/4 and bus
mastering Ultra DMA/33. The peak transfer rate of PIO mode 3/4 can be
as high as 17MB/sec. Using HDDs that support Ultra DMA/33, the peak
transfer rate can reach 33MB/sec. There are two IDE connectors -
primary IDE and secondary IDE. With two devices per connector, up to
four IDE devices can be supported.
3.10 DMA Channels
There are seven DMA channels available on the motherboard; only
DMA2 is used by the floppy controller. In the case that ECP mode on the
parallel port is utilized, DMA1 or DMA3 will be used.