IBM PC printer adapter schematic

[Allison]

>
>Subject: Re: IBM PC printer adapter schematic
>   From: "Ethan Dicks" <ethan.dicks at gmail.com>
>   Date: Sat, 07 Apr 2007 18:29:29 -0500
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 4/7/07, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
>> I wrote:
>> > That's handy to know - every once in a while, I long for a machine
>> > with 2 or 3 parallel adapters, for things like old Connectix cameras,
>> > LCD displays and the like.  I've never assembled an ISA machine with
>> > more than one printer adapter....
>>
>> Well, you can have as may printer adapters as yopu like if you can set
>> them all to different addresses and if you're writing your own software
>> to talk to them...
>
>Naturally.  The problem I see is that only the older cards might let
>you set the printer port to respond to arbitrary addresses - the ones
>I have are almost (entirely?) all of the style where you move a single
>jumper for LPT1 vs LPT2 (primary vs secondary address).
>
>I wasn't as worried about the OS interpretation since I don't intend
>to *print* to my printer port.


The current system has three printer ports in it!  No big deal and there
are standard addesses that the OS (win or nt) recognize with no difficulty.
I use three as one is dot matrix (LQ570), one Laser (HP4l) and the third
is inkjet(color).   I happen to be using the a PCI, ISA and mainboard
based ports so where's the problem?

All the ISA cards I have allow for at least two if not many more possible 
printer ports. And same for serial, though after two the IRQ assignments
can be weird.


Allison