On 5/27/21 4:17 PM, Fred Cisin via cctalk wrote:
I modified a PC parallel port, and played around with it. My goal,
XenoComm Parallel, was NOT to use it with software on both machines. I
had run into a few machines that had a Centonics port, but not RS232,
and disk formats that the PC FDC couldn't handle. (such as TRS80 mdel 1,
Sirius 9000, Vector Graphics, etc.), I wanted to connect their parallel
printer port to a PC, tell the alien machine to PRINT its word processor
files, and have the PC emulate a printer to the alien machine, but
capture and save what the alien machine "printed".
From about 1988 to 2000 I marketed a very successful
product to the law
enforcement community. One of the facets of it was the ability
transfer data from a subject machine via serial or parallel connection.
We could do either nibble-or-8 bit transfers, but nibble turned out to
be the most used. Lots of error checking and waiting for lines to
settle, but, like laplink and interserver, it could be done quite well
and it was faster than serial.
I seem to recall that the Victor 9000 had a bidirectional parallel
interface that could also double as a GPIB interface. Sometime around
1987, I wrote a parallel port TSR that could drive slow-speed GPIB
devices. I wrote it out of necessity--I needed to make a presentation
that involved color charts and the only plotter I could borrow was the
HP 6-pen plotter with GPIB interface. At the time, I was using
SuperCalc, which supported the parallel version of the plotter, so I
wrote a TSR to hook the INT 17H BIOS interrupt and directed the messages
through a printer port connected as a GPIB interface.
That one worked with the legacy PC printer port. Later, I modified the
port to be bidirectional and used it with an HP GPIB voltmeter.
I know the thing was discussed briefly in Nuts'n'Volts; it may still be
in the SIMTEL20 archive.
Years ago and far away...