Subject: Re: interrupting parallel port lossage
To: John F. Woods <jfw@jfwhome.funhouse.com>
From: Ken Hornstein <kenh@cmf.nrl.navy.mil>
List: port-i386
Date: 03/22/1995 10:34:05
>According to the manual with my printer, the data strobe is supposed to have
>.5us of setup time, .5us of data strobe, and .5us of hold time.  I think that
>the driver probably ends up cheating on those numbers on a fast processor,
>but adding a delay(1) didn't seem to help.  (On the other hand, it was
>recently mentioned that delay() isn't accurate for small values.)  I would
>also suspect that it varies with different printers; I vaguely recall that
>an older printer of mine required 1us for each of the above times, but I
>can't find the manual.

Hm, thinking about about the testing I was doing last night, I generally was
able to print longer files while I was compiling something (as I mentioned
in another note, it turns out the inb() I added really didn't work).  I'll
try playing with this some more.  Judging from the data corruption I was
getting, maybe the hold time isn't long enough.

--Ken