Subject: Re: parallel port ECP
To: Brian Gregor <bgregor@buphy.bu.edu>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: current-users
Date: 08/29/2000 13:53:09
On Tue, Aug 29, 2000 at 01:01:11PM -0400, Brian Gregor wrote:
> 
> Is the ECP mode of the i386 parallel port supported?  If not, are
> there plans to do so?  If it is, how can I make sure it's being
> used?  
> 
> Printing to an HP 2100M LaserJet is very slow off of my NetBSD
> server.  Unfortunately, the printer doesn't have a USB port
> or I'd try that.

The problem almost certainly has nothing to do with which parallel port
mode is in use.  The parallel port interupts are very lightweight and can
be turned around insanely fast by almost any modern (or even not-very-modern)
x86 hardware, so plain-old-parallel-port basically *will* exceed the ability
of your printer to render pages.

What usually speeds things up immensely is to add a bunch of memory to the
printer.  Then the printer can buffer incoming data in RAM while it images
pages it's already got.  Most HP printers will happily take the spare RAM
you've got lying around from old 486 or Pentium machines (that is, 72-pin
FPM or possibly even EDO SIMMS) -- try it.

Don't be surprised to see interrupts/sec figures in the high thousands from
your parallel port as the printer sucks up data as fast as it can.  This is
normal and causes no real harm.