PARCP cable and UNI-BI HW adapter:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The following diagrams shows you how to build your own parallel cable for
use with my PARCP (PARallel CoPy). This cable allows you to connect your
computer with any other computer if both machines have bidirectional
parallel ports.

WARNING: If you have got PC with unidirectional parallel port only (you can
find it out by running enclosed PARTEST.EXE), you will also have to build
and use the UNI-BI HW adapter (see below).

Note that I give you no warranty about this diagrams and about my PARCP.
Although it works fine for me and my friends (PARCP was tested on many
different machines including ST, STE, Falcons and PC's from 386 up to 686)
your mileage may vary.

If you don't use the UNI-BI HW adapter you should connect the parallel
cable only after starting PARCP or PAR_IN on one computer (at that time its
parallel port is switched to input state and can be connected with the
other parallel port without a risk of damage both parallel ports).

Also make sure the computers are on the same electrical ground otherwise
you will get a nice fire of cable and parallel ports :) Putting both
computers' power cables to the same power outlet is always a good idea.

1) Bidirectional PARCP cable:
=============================

Cannon-25 male                     Cannon-25 male
 1 ............................... 11  (Strobe -> Busy)
 2 ...............................  2  (Data 0)
 3 ...............................  3  (Data 1)
 4 ...............................  4  (Data 2)
 5 ...............................  5  (Data 3)
 6 ...............................  6  (Data 4)
 7 ...............................  7  (Data 5)
 8 ...............................  8  (Data 6)
 9 ...............................  9  (Data 7)
11 ...............................  1  (Busy <- Strobe)
25 ................................25  (GND <-> GND)

Note: This cable also works with ST-Trans (c) Atari 1992
      and with plip protocol of MiNT-Net (c) Kay Roemer.


2) UNI-BI HW adapter (for PCs with unidirectional parallel port only)
=====================================================================

UNI (PC port)                      BI (PARCP cable)
Cannon-25 male                    Cannon-25 female
 1 ..............................  1
 2 -> IC1.2              IC1.19 <- 2
 3 -> IC1.3              IC1.18 <- 3      The IC's are also wired together:
 4 -> IC1.4              IC1.17 <- 4
 5 -> IC1.5              IC1.16 <- 5      IC1.10 ..... IC2.8 + IC2.15
 6 -> IC1.6              IC1.15 <- 6      IC1.11 ..... IC2.1
 7 -> IC1.7              IC1.14 <- 7      IC1.12 ..... IC2.10
 8 -> IC1.8              IC1.13 <- 8      IC1.13 ..... IC2.6
 9 -> IC1.9              IC1.12 <- 9      IC1.14 ..... IC2.13
10 -> IC2.9                               IC1.15 ..... IC2.3
11 .............................. 11      IC1.16 ..... IC2.11
12 -> IC2.7                               IC1.17 ..... IC2.5
13 -> IC2.12                              IC1.18 ..... IC2.14
14 -> IC1.1                               IC1.19 ..... IC2.2
15 -> IC2.4                               IC1.20 ..... IC2.16
16 -> IC1.20 + IC2.16
17 -> IC1.11 + IC2.1
25 -> IC1.10 + IC2.8 + IC2.15 ... 25

IC1 = 74HC574
IC2 = 74HC257

I think the *HC* is important, because both IC's eat current from PC's
parallel port and the maximum draw from it can be about 10 mA only IIRC.

Note: I'm sure you noticed the adapter had a female connector on one side.
      Yes, there you should connect the bidirectional parallel cable so you
      get the full bidirectional transfer even if your PC has got
      unidirectional parallel port only.

      Of course you could make a direct UNI-BI cable (with male connectors
      on both ends) but I think that a simple BI cable and a small UNI-BI
      adapter is more flexible solution, because one day in future all PCs
      will have those bidirectional ports and then you simply throw the
      UNI-BI adapter away :) Until then PC is one step behind Atari
      computers because we have had bidirectional ports since 1985!!
      <Power without Price>

Some people have problems with understanding the correct wirring, so here
are little examples of possible 'net' combinations:

Computer A:                                        Computer B:
-----------                                        -----------
Atari ST   <-------- bidirectional cable ---------> Atari ST

Atari ST   <-------- bidirectional cable ---------> PC with BP (bidir.port)

PC with BP <-------- bidirectional cable ---------> PC with BP

Atari ST   <------- bidir. cable ------|<UNI-BI HW> PC with UP (unidir.port)

PC with BP <------- bidir. cable ------|<UNI-BI HW> PC with UP

PC with UP <UNI-BI HW>|- bidir. cable -|<UNI-BI HW> PC with UP

I hope you can see that you can connect any computer with any other one -
you simply put the UNI-BI adapter to the unidirectional port and then you
can easily connect it to other computer with bidirectional cable.

By the way - the HDD Daemon version 2.1 and higher does support my UNI-BI HW
adapter...

Petr [stehlik@cas3.zlin.vutbr.cz | 90:1200/0@nest.ftn | 2:421/36@fidonet.org]
