OT: <was springfield> <is data transfer via parallel port off old systems>

Don Y dgy at DakotaCom.Net
Wed Aug 2 14:30:54 CDT 2006

jim stephens wrote:
> Chuck Guzis wrote:
>> On 8/2/2006 at 11:32 AM Don Y wrote:
>>> Unfortunately, you then need *one* box with hardware suitable
>>> to capture the incoming bytestream (i.e. *not* an SPP).
>> I know this is a vintage list, but at a minimum, PS/2-style bidirectional
>> parallel ports have been around for a very long time, so this 
>> shouldn't be
>> a problem.  Even if you had an old XT, printer and monochrome adapter 
>> cards
>> can usually be modified to operate in bi-directional mode.
>> After that, it's just the cable and a bit of software on the receiving
>> side.
> I have a "vintage" IBM PS/2 data migration facility box with appropriate 
> dates, so it is
> not too off topic.  Anyone out there with a recipe or howto pointer to 
> do this with various
> os varieties?  Say linux 2 linux, or linux to dos?
> Also, I do not believe that the output to the printer port that Don 
> suggested assumed the
> protocol that the parallel port data coupler uses is available.

No.  I am assuming *no* protocol!  I.e. the source machine just
*pushes* bytes out the parallel port.  Leave it to the receiving
device to figure out how to get them *in* and some "external"
mechanism to verify that the transfer was error-free (e.g., the
MD5, CRC, "send it twice" ideas).

The whole point of my proposal was to not require *anything*
on the source machine other than the ability to cat(1) to
/dev/lpt in some fashion.  All of the work is done on the
other end -- by the recipient.  And, you only need *one*
box with that capability (hardware/software)... presumably
also having the ability to move the file that it receives
out to the network, onto other storage media, etc.

> To fork the thread, I would be interested in whether the SCO parallel 
> drivers might
> support the parallel port in such a way as to allow such coupling, 
> (reads get data from port that is).

This is what I was avoiding!

> Also what is required to do this simply or other wise on Linux 
> (mentioned above).
> Even better, is there a small program to do this to a dos box, that can 
> be used
> on dos / old windows boxes.
> Laplink had cables for the serial port, I don't recall if it had a 
> parallel version
> that was reliable, as far as dos to dos data transfer.

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