Specifications

CoreModule/PC Technical Manual
2-20
The PC expansion bus provides a number of interrupt and DMA control signals. When you
interface the CoreModule/PC to other MiniModules, PC bus plug-in cards, or other logic that
requires either interrupt or DMA support, you must select which channels of these functions will be
used by the added functions. This is typically done using either switches or configuration jumpers
on a plug-in card. Check that you do not configure the added card to use an interrupt or DMA
channel that is already being used! For your convenience, Tables 2-16 and 2-17 provide a summary
of the normal assignment of interrupt and DMA channels on the CoreModule/PC and commonly
used expansion modules.
Interrupt Typical Use
IRQ2 EGA/VGA Option*
IRQ3 Secondary Serial Port (COM2)
IRQ4 Primary Serial Port (COM1)
IRQ5 Secondary Parallel Port (LPT2)**
IRQ6 Floppy Controller
IRQ7 Primary Parallel Port (LPT1)**
∗ This interrupt is sometimes assigned to a VGA
controller, but is normally not required on Ampro
VGA adapters.
∗
∗
The printer port interrupt is normally disabled and
available for other devices on the bus.
Table 2-16. Bus Interrupt Assignments
DMA
Channel
Typical Use
0 DRAM Refresh
1 Available
2 Floppy controller
3 SCSI controller (on MiniModule/FSS)
Table 2-17. DMA Channel Assignments
The CoreModule/PC is designed to offer a great deal of flexibility of applications. One obvious
choice is to expand the system as necessary with the various Ampro MiniModules and other PC/104-