[comp.sys.ibm.pc] Why no Parallels?

Isaac_K_Rabinovitch@cup.portal.com (02/17/88)

murillo@sigi.Colorado.EDU (Rodrigo Murillo) writes:
->In article <673@pasteur.Berkeley.Edu> landay@cory.Berkeley.EDU (James A. Landay)
->writes:
->>Is there a way to hook to PCs together via the parallel ports?
->
->Check out PC Magazine, January 12, 88 Vol. 7 Number 1.
->There is a whole section on data transfer programs that would meet
->your needs.  Not all support parallel file transfer though. Here
->are some that do:
->
->     Direc-link     (213)377-1640
->     Paranet        (613)236-1487 
->     File Shuttle   (800)663-8066
Thank you Mr. Murillo!  Plenty of people are going to check out your
info.

One thing I don't understand:  why don't more packages support parallel?
There are good reasons to prefer it over serial:  it's faster,
one is more likely to have a parallel channel free (every desktop add-on
board maker seems to like to throw them in, and laptop makers consider
them essential but serial channels an option).  Until now, I had assumed
that there was some factor I didn't understand that made that approach
impossible.

Isaac Rabinovitch
Disclaimer:  Just because I think you're wrong, doesn't
             mean I don't think you're a fun person!
:-)

pjh@mccc.UUCP (Peter J. Holsberg) (02/18/88)

In article <3271@cup.portal.com> Isaac_K_Rabinovitch@cup.portal.com writes:
|
|One thing I don't understand:  why don't more packages support parallel?

My understanding is that the PC's parallel port is set up by the BIOS to
be "output-only".  (Of course, port B on that 8255 *could* be
reprogrammed  to make it an input port, so I'm as puzzled as you!)
-- 
Peter Holsberg                  UUCP: {rutgers!}princeton!mccc!pjh
Technology Division             CompuServe: 70240,334
Mercer College                  GEnie: PJHOLSBERG
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jgray@toad.pilchuck.Data-IO.COM (Jerry Late Nite Gray) (02/24/88)

In article <223@mccc.UUCP>, pjh@mccc.UUCP (Peter J. Holsberg) writes:
> In article <3271@cup.portal.com> Isaac_K_Rabinovitch@cup.portal.com writes:
> |One thing I don't understand:  why don't more packages support parallel?
> 
> My understanding is that the PC's parallel port is set up by the BIOS to
> be "output-only".  (Of course, port B on that 8255 *could* be
> reprogrammed  to make it an input port, so I'm as puzzled as you!)

We were wondering about the same thing a while back in trying to consider
how to make a better connection to the PEECEE. One of the things that turned
up was that the parallel ports in many so-called compatibles have slightly
differently implementations as far as reading is concerned. Reading a port
MAY be possible but it frequently requires changing a jumper or cutting a 
trace or two to get it to work. I don't know the exact details of this
(I personally didn't look into the problem). 

Maybe someone else out there can fill in the details.


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