Re: Printing

(YngV@gnn.com)
Fri, 26 Jul 1996 22:11:42

>
>I asked a question concerning printing over a week ago and didn't get a
>response, so I'll ask again to see if maybe it wasn't received.
>
>I use the omniprn program that allows Omnigo printing via a PC to a
> laserjet. I
>noticed that when my batteries were low, especially on the higher baud
> rate of
>19200, there was a lot of noise and incorrect printing. If I used fresh
> high
>quality alkalines, the printing improves, but is still not perfect. If I
> use an
>AC adaptor, the printing is great even at the high transfer rate of 19200
> bps.
>
>It seems like the serial data quality is linked to the power level in the
>batteries. How can this be since both sender and target are digital?
> Does this
>occur with other applications that use the serial cable such as Installer
> and
>the Connectivity Pack?
>
>Any clues? Thanks.
>

you would've figured at least _I_ would have responded, huh? :-)

Your theory sounds as good as any I've figured. It's a low power computer
and I'm sure it's signal to noise if pretty low, so if your batteries are
weak and you're draining them further with the COM port, it's very possible
the lines get dirty (although I'm not an electrical engineer, I'm familiar
with some of this stuff).

My question to the community is...

Is anyone out there using a real serial to parallel cable directly hooked to
a printer, and if so, are you experiencing the same things?

The answer to other comm programs like the installer and Omnicom is that they
probably use a method of verifying the data as it comes across, via checksum
or whatever. I know PCCOM file transfer uses a checksum routine. It would
explain why moving a small file takes a comparatively long time.
Unfortunately, with direct port stealing, my program is at the mercy of the
data coming over -- it is unverifiable.

keep ideas coming....

jv