Date   : Thu, 21 Jan 1999 21:39:23 +0100
From   : "Mark Usher" <marku@...>
Subject: Parallel cable for the BBC

After getting fed up with the snail pace of the serial port for transferring
data across to the PC, I thought I'd look in to wiring up a parallel 4bit or
"laplink" cable to do the transfers via the user port.

Well, it looks like it's working - the cable that is, so I thought I'd share
the pin outs with you all incase anyone else wants to mess around with it,
or can spot any mistake I may have made. It's also handy incase I lose the
bit of paper I jotted this down on :-)

BBC USER PORT   PC PARALLEL
 1     +5v
 2    CB1        6  D4
 3    +5v
 4    CB2       15  -ERROR
 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       10  -ACK
15    0v        23  GND
16    PB5       11  -BUSY
17    0v        24  GND
18    PB6       12  Paper End
19    0v        25  GND
20    PB7       13  SLCT

Now for some software......

Anyone for connecting the 1MHz bus to USB :-)
It could actually be possible to use the printer solely as output and the
User port as input for a ECP implementation, which would again speed things
up.

Mark