Date   : Mon, 25 Jan 1999 20:28:32 +0100
From   : "Mark Usher" <marku@...>
Subject: Parallel cable revision

Hi

Here is a revision of the cable I was talking about last week. I've been
playing with it over the weekend (thanks to Stuart for his help and guidence
with ASM) and have now some simple byte transfer with a hardware handshake.
Just a slight problem with an interrupt though... I'll probably post the
program here when it works a little better and with the initiation being
started at either end.

Mark


BBC USER PORT   PC PARALLEL
 1     +5v
 2    CB1        6 D4
 3    +5v
 4    CB2       11 -BUSY
 5    0v        18 GND
 6    PB0        2 D0
 7    0v        19 GND
 8    PB1        3 D1
 9    0v        20 GND
10    PB2        4 D2
11    0v        21 GND
12    PB3        5 D3
13    0v        22 GND
14    PB4       15 -ERROR
15    0v        23 GND
16    PB5       13 SLCT
17    0v        24 GND
18    PB6       12 Paper End
19    0v        25 GND
20    PB7       10 -ACK

or put another way:

USER  CB2 -> -BUSY    PRINTER
PORT  CB1 <- D4        PORT
       D7 <- -ACK
       D6 -> PaperOut
       D5 -> SELECT
       D4 -> -ERROR
       D3 <- D3
       D2 <- D2
       D1 <- D1
       D0 <- D0