IBM 770 manual Infrared IR Subsystem, DMA Channel, Subsystems

Infrared (IR) Subsystem

The IR subsystem supports the following functions:

ŸMIF/FIR mode

–567 Kbps

–1.152 Mbps

–4.0 Mbps

ŸSharp** mode

–9,600 bps

The I/O address can be selected from the following with the system utility program. The IR subsystem uses one serial port address and one IR controller register address:

I/O Address
03F8–03FF	Serial		port	1	(default)
02F8–02FF	Serial		port	2
03E8–03EF	Serial		port	3
02E8–02EF	Serial		port	4
03F8–03FF	IR	controller			register	1 (default)
02F8–02FF	IR	controller			register	2
03E8–03EF	IR	controller			register	3
02E8–02EF	IR	controller			register	4

IRQ

Level

and

DMA Channel

The

IR

subsystem uses

one

IRQ

level

and

two

DMA

channels for

ThinkPad

mode. (Generic

mode

and

Sharp

mode

do

not

require

DMA

channels.)

IRQ

Level

DMA

Channel

IRQ

3

DMA

0

IRQ

4

(default)

DMA

3

IRQ

5

IRQ

10

IRQ

11

IRQ

15

Subsystems 3-9