On 5 July 2010 01:24, Fred Cisin <cisin at xenosoft.com> wrote:
> 20 years
ago, I set up an IBM AT to emulate a printer. ?I based it on
> Bruce Eckel's Microcornucopia parrallel port interfacing articles. ?I used
On Mon, 5 Jul 2010, Liam Proven wrote:
I did that, around that time, too.
I had to get all the files off an ancient dedicated wordprocessor -
possibly a QUME or a Wang box, I forget now. It had a weird floppy
format - I don't remember the details, maybe 8", maybe hard-sectored?
No way to read 'em on a 1980s PC, anyway.
Its printer was a serial daisywheel of no known type or compatibility.
So I wrote a QuickBASIC app for a PC to receive data from the serial
port and dump it in files. I wired up a nullmodem cable, loaded each
The one that I was dealing with was "Centronics" parallel, but Eckels had
described in detail how to modify one of the common parallel ports for
bi-directional, and I wired up a cable with the opposite gender blue
ribbon connector, so that the alien machine thought that it was talking to
a printer.
In retrospect, a parallel to serial adapter would probably have been
easier.
file on the WP, then printed it. The PC asked for
a filename, captured
it, stripped out all the non-ASCII, single carriage returns and things
like that, then saved it to disk. As it was a daisywheel, there was no
formatting information worth noting; it did a backspace-and-overprint
for bold, a code for underline which I think I threw away, and that
was about it.
Most (not all) of the early daisy wheels did underline with a backspace
and an underline character.
Yes indeed - I had an Amstrad PCW9512 at the time, which did this -
but I was only trying to recover raw text. I'd have had to find how to
write some kind of formatting info into the file to preserve bold &
underline, and that was just too much work. I don't think that back
then I had any DOS app smart enough to do a global search-and-replace
that would turn text codes into formatting, and while my work box (a
6MHz IBM PC-AT with 512KB) did dual-boot into SCO Xenix, which
doubtless could have done this, my Unix-fu is very weak.
But then I
found a problem: it did bidirectional printing. In
*software*. For every other line, it printed
[character][backspace][backspace][character][backspace][backspace]...
etc.
Howzbout: capture line to buffer, (or read from the file), and look for
the double [backspace]s ??
Do you know, I might have done that. It was a very long time ago, I
don't remember the details.
What was even more fun was transferring files TO a
machine with no real
connectivity (a Merganthaler from hell). ?Box of solenoids on the
keyboard!
O_o
I think I'd have sent such a client to a professional media-conversion
company, myself!
--
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