"Interfacing the IBM PC parallel printer port" - читать интересную книгу автора (Stewart Z.)

D6 8 => 10 S6+ direct
D7 9 => 11 S7- inverted

C0- 1 <=* 2 D0 inverted
C1- 14 <=* 3 D1 inverted
C2+ 16 <=* 4 D2 direct
S3+ 15 <=* 5 D3 direct
S4+ 13 <= 6 D4 direct
S5+ 12 <= 7 D5 direct
S6+ 10 <= 8 D6 direct
S7- 11 <= 9 D7 inverted
C3- 17 <=> 17 C3- direct (OC shared)

Gnd 25 === 25 Gnd (ground)

* Note: Control outputs used as inputs must be programmed high:
C0, C1, C3 = 0 and C2 = 1

[A future version of this document may sketch out the code to send and
receive data through these connections]

17. Capturing "printed" data from another machine

A computer with a bidirectional printer port, connected with a Mode 2
cable to any standard port, could potentially pretend to be a printer
so as to capture the "printed" information. It would configure its
Data port for input, and set appropriate values on its Control Out to
mimic a printer on the other computer's Status In lines. In the general
case, the problem would be detecting the very brief -Strobe pulse; this
would either require an external TTL latch triggered by -Strobe (either
edge), or some way to sense a quick pulse on that line. In the latter
case, a revised connection (call it Mode 2B) could connect the "printing"
computer's -Strobe (C0-) line to the receiving computer's -Ack (S6+) line;
the trailing edge of the printing computer's -Stobe would generate an
interrupt on the receiving computer. I have not tried this. Of course,
the +Busy line would also be needed to avoid data overflow; perhaps it
could be kept high (busy) most of the time, but pulsed low after reading
the data (which would be handled by the IRQ routine).

[If anybody has had some success with this, let me know.]

18. Controlling Outputs

This can be easy; just use the Data Out TTL signals to control TTL level
items. Unfortunately, they cannot source much current (providing positive
voltage on the pin, relative to ground) - be careful of the 2.6 mA limit.
Some LSI implementations might allow more or less than this (likely less).

Dn Out ------+
|+