John S Davison tests a replacement for the 850 interface from
Frontier Software at £69.95
The Right Connection?
If, like me, you've always cursed Atari for not
providing the 8-bit machines with standard serial and parallel
interfaces, then you'll be interested in the P:R:Connection from ICD
Inc. of Rockford, Illinois. Using this device you'll be able to
connect to standard (non-Atari) printers, modems, other computers,
or any other peripheral device requiring a 'Centronics' type
parallel or RS-232 serial interface.
Until now the only way to get hold of this product
was to import one directly yourself, although Silica Shop did
advertise it a while back. I've just heard that Frontier Software
have become the UK distributor for ICD products, and can supply the
P:R:Connection (PRC) along with many other interesting ICD 8-bit
accessories. The review model came in via the import route, and this
gave rise to a disastrous problem I'll describe later.
The package as supplied includes the interface box
itself, a detailed instruction manual, and a double sided disk
containing mainly communications software. No device cables are
provided – you have to supply these yourself.
ICD intend the PRC to be a straight replacement for the expensive
and elusive Atari 850 interface. It's virtually 100%, compatible,
including use of the 850 cables. In the few instances where there
are compatibility issues, these may be fixed by using a supplied
'translator' program.
CABLE COSTS
Finding suitable, reasonably priced device cables
was a problem. I had several quotes for 850 cables at around £20 and
over (EACH!), which I think is appalling. How can companies justify
charging such horrendous prices for cables? ICD sell them for half
this in the USA, so why can't UK companies manage something similar?
Frontier Software could generate a lot of goodwill (with me, at
least!) if they sold ICD cables too. (Frontier are now handling
these cables at a reasonable price. Ed.) I eventually found some at
a more acceptable price at York Computer Centre.
A SMALL PLASTIC BOX
The PRC itself is a small plastic box measuring
about 5" x 3.5" x 1" with a standard Atari serial bus cable emerging
from one side. This plugs into the Atari's serial socket, and you
then plug the rest of your I/O daisy chain into the serial bus
socket on the PRC. There's no separate power supply needed (yippee!)
as the PRC draws its power directly from the computer via the serial
bus connection. It works fine unless you happen to own a 1200XL.
This needs a simple hardware modification for which instructions are
provided.
On the opposite side of the case are the I/O ports
– one parallel and two serial. "P1:" is the 'Centronics' parallel
printer port, using a DB15 socket. "RI:" and "R2:" are both RS-232
serial ports, using DB9 sockets. The former is a full serial port
containing all the handshaking lines required by certain modems,
while the latter is a cut down version handling only receive and
transmit lines. The old Atari 850 interface had two additional
ports, one of which provided the rarely used 'current loop'
facility. They were omitted from the PRC in order to keep down
costs.
Inside the grey case is a very neat circuit board
containing a number of discrete components and several IC chips. One
of these is a complete microprocessor in its own right, containing
ROM, RAM, PIA, and a CPU! The board also contains two
jumper switches. One can be set to provide auto-linefeeds for your
printer – useful if you swap the printer between 8-bit and ST
machines, as it removes the need to fiddle with those annoying
printer DIP switches. The other switch allows you to turn the
printer function off, again useful if you're already using a
directly connected Atari printer.
EARLY MODEL PROBLEMS
My first test involved replacing the trusty
Blackthorn interface I use to drive my Star SG10 printer. It took
just a few moments to connect up the PRC in its place and to try a
few quick LPRINT commands from BASIC. Result – Error 143. Hmmm, not
so good. I rechecked all cable connections and retried it. Same
result. I tried to LIST a BASIC program instead. No good. I tried to
print a document with Atariwriter Plus. Still nothing. No amount of
experimentation would induce it to print. Disaster!
At the time I wasn't aware that Frontier Software
were about to start handling ICD products, so I contacted Silica
Shop who kindly offered to help me sort out the problem. I took the
PRC and cables down to them and we tried
substituting different cables, computers, and their last remaining
PRC. Surprisingly, even this didn't work. (Thanks anyway, fellas!)
Baffled and disappointed, I went home and wrote to
ICD in the USA. A few days later I received a phone call from ICD
president Tom Harker, who explained that the first few thousand
PRC's made were incompatible with PAL system 8-bit machines (i.e.
those used in the UK). The design was subsequently modified to fix
this, so my PRC (and Silica's?) must have been an early model. The
solution was to replace the 4 MHz crystal on the PRC's board with
one of 3.9 MHz. I received a replacement crystal from him by airmail
shortly after, and fitting this caused the PRC to drive my printer
exactly as the Blackthorn had. Moral – if you import your own
hardware from the USA make sure you know what you're getting!
SOFTWARE REQUIREMENTS
When used to drive a parallel printer no
additional software is required – simply plug in the PRC and go.
Using the RS-232 interface is rather more complex, needing some form
of driving software. This is where the ICD supplied disk comes in,
as it contains a number of useful programs.
There are three (yes, three) different
communications programs provided. All are public domain programs and
widely used in the USA. The first is AMODEM 7.2, considered by ICD
to be one of the best communications programs available for the
8-bit machines. Then there's my favourite – 850 Express, a modified
version of 1030 Express, which is immensely popular in the USA. Just
looking at it I can see why – it's got some superb features!
Finally, there's RSCOPE, needed only if you're rich enough to afford
to access and download programs from the USA's CompuServe system.
There's no separate documentation provided for
this software – it's all on the disk, so you can either print it out
or view it directly on the screen via a text editor.
I haven't had a chance to try out the
communications side of the PRC and its software yet, so I'll defer
comment on it until the next issue. Watch this space for details.
ICD's P:R:Connection is great news for 8-bit
users. At last you can be freed from the straightjacket of Atari
specific printers and choose virtually any one that takes your fancy
(modems too!). Considering you also get a diskful of useful software
it's superb value for money. If you need a good, comprehensive
interface device for your 8-bit machine, then look no further. Get
ICD's P:R:Connection,
