user manual

Block Diagram
http://www.motorola.com/computer/literature 3-9
3
Asynchronous Serial Ports
The two asynchronous ports provided by the ISASIO device employ
TTL-level signals that are buffered through EIA-232-D drivers and
receivers and routed to the P2 connector.
Hardware initializes the two serial ports as COM1 and COM2 with ISA
I/O base addresses of $3F8 and $2F8 respectively. This default
configuration also assigns COM1 to PIB (PCI/ISA Bridge Controller)
interrupt request line IRQ4 and COM2 to IRQ3. You can change the
default configuration by reprogramming the ISASIO device. For detailed
programming information, refer to the PCI and ISA bus discussions in the
MVME2603/2604 Programmer’s Reference Guide, listed in Appendix D,
Related Documentation, and to the vendor documentation for the ISASIO
device.
Parallel Port
The parallel port is a Centronics printer interface in MVME712M-
compatible models, and a full IEEE1284 bidirectional parallel port in
MVME761-compatible models. Both versions are implemented with the
ISASIO device. All parallel I/O interface signals are routed to P2 through
series damping resistors.
Hardware initializes the parallel port as PPT1 with an ISA IO base address
of $3BC. This default configuration also assigns the parallel port to PIB
(PCI/ISA Bridge Controller) interrupt request line IRQ7. You can change
the default configuration by reprogramming the ISASIO device. For
detailed programming information, refer to the PCI and ISA bus
discussions in the MVME2603/2604 Programmer’s Reference Guide,
listed in Appendix D, Related Documentation, and to the vendor
documentation for the ISASIO device.