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

[Don Y]

Roy J. Tellason wrote:
> On Wednesday 02 August 2006 05:44 pm, Don Y wrote:

>> I wire each of these widgets for a specific purpose:
>> - gender changers (M->F, F->M)
>> - "null modem", "null terminal"  :-/
>> - PLIP
>> - Sun "port A/port B" swap
>> - device specific requirements (some devices use unusual
>>    pins for handshaking, etc.)
>> - etc.
> 
> If you have that info in a file I sure wouldn't mind taking a look at it.  
> Could come in handy some time.  I know I've run across the odd bit now and 
> then.

Most of the "typical" ones are pretty intuitive.  Though
"null terminal" was a bit of a head-scratcher.

> Like the DEC printer that was the exact same mechanism as several others I'd 
> seen around that time (Apple imagewriter?  Some others I can't recall) but 
> which required one of the handshake lines to be pin 10,  or maybe it was 11.  
> Nothing special about that printer,  and it was really pretty slow compared 
> to a lot of others out there (though not as noisy either),  with one 
> exception -- when you fed it a "*" it printed an actual 5-pointed star.  Only 
> printer I've ever seen that did that.  :-)

Some devices put power on certain pins, some devices use pins
for nonstandard reasons, etc.

>> Instead, I dynamically fabricate the cable that I need by patching lengths
>> of straight through M-F cables together.  Then, apply whatever combination
>> of "widgets" are needed on each end (in theory, you only need to do this on
>> one end but sometimes you need a 25->9 pin adapter and other times its
>> easier to do some of the "widgeting" on each end instead of having 2 or
>> three cascaded widgets hanging off one end of the cable)
> 
> Just so.  Those things stretching out horizontally behind an item of equipment 
> sometimes doesn't work real well either,  so a short cable at that end to let 
> 'em hang might be another option.

Yes, instead of using "9 pin widgets", I use short 9-25 pin
pigtails when I need to make that sort of adaptation for exactly
this reason.

> Is there a standard about which parts of that stuff are supposed to get the 
> screws and which are supposed to get the little threaded posts and such?  I 
> bumped into hassles with that already,  too.

The shells that I have accommodate jack screws on one end -- so
I let that decide where to put each bit of hardware.