Toshiba M40 Communication Comm, Diagnostic Programs Communication, Subtest 01 LPT, Status Line

3 Diagnostic Programs 3.9 Communication

3.9Communication (COMM)

Subtest 01 LPT

This test item is to check whether there is open or short circuit issue in the external pins by looping back the external pins, controlling the voltage of each data pin, control pin and status pin.

The test requires an external connector to insert into the tested LPT port. Below is the connector's description.

Fixture Description:

(9)+ PD7

(8)+ PD6

(7)+ PD5

(6)+ PD4

(5)+ PD3

(15)-ERROR

(14)-AUTFD

(13)

(16)-PINIT

(1)- STROBE

(10)- ACK

(4)	+ PD2	(12) + PE
(3)	+ PD1	(17) - SLIN
(2)	+PD0	(11)+ BUSY

Note: (1)~(17)	--------	Pin number
PD0~ PD7--------		Data Line
Status Line --------	–ERROR(S3), +SELECT(S4), –ACK(S6), +PE(S5), +BUSY(S7)
Control Line --------	–AUTFD(C1), –PINIT(C2), -STROBE(C0), –SLIN(C3)

1. Register Check

Check whether the data register and control register works normally.

2. IRQ Check

Check whether LPT interrupt works normally.

3. External Loop back

Check whether there is open or short circuit issue.

4. ECP Mode

54 Satellite M40/M45 TECRA A4 Dynabook Vx/4 Maintenance Manual