[sebhc] printer driver

[Barry Watzman]

Let me make a suggestion:  If someone will photocopy the original H14 manual
to individual 8.5"x11" pages (single or double sided), and send those to me,
I will convert them to a PDF file.  I have a high-end scanner with ADF and
can do this relatively quickly and easily.

In making the copy, remember, GIGO (Garbage In, Garbage Out).  The PDF will
be no better than the photocopies.

Barry Watzman
Watzman at neo.rr.com


-----Original Message-----
From: sebhc at sebhc.org [mailto:sebhc at sebhc.org] On Behalf Of Lee Hart
Sent: Tuesday, February 22, 2005 4:54 PM
To: sebhc at sebhc.org
Subject: Re: [sebhc] printer driver

>> If I remember it used to calculate the printhead temp by monitoring
>> the resistance of one of the printhead coils?

Yes, that is correct.

Dave Dunfield wrote:
> I do recall the thermal limiting after you had printed a few lines.
> I don't think mine waited "5 to 10" minutes, but I do recall that
> it would go into mode with a few second delay between each line

Also correct. The temperature sensing circuit had two outputs to the
microcomputer; 'warm' and 'hot'. A 'warm' head added a few seconds delay
between lines. A 'hot' head stopped printing entirely until the head
temperature came back down to 'warm'.

The peak printing rate was actually quite high; 165 chars/sec. That was
actually pretty fast in those days.

> anyone have a scan of the H14 manual?

No scans, but I have the original manual. Send me your address offline
and I'd be happy to loan it to you (if you promise to return it).

> My very first printer was a Teletype Model-28, which I generated
> baudot data for by toggleing the interrupt-enable line on my first
> homebuilt 8080 (didn't use interrupts in that system) - now that's
> going a long way back!

Yes indeed! My first printer was a baudot teletype, left over from my
ham radio RTTY work. 60 baud -- now *that* was slow!

I graduated up to a Selectric typewriter with a board to run it as a
printer. 137.5 baud, and another oddball shift/rotate code to deal with.

So, the H14 was actually quite a step up!
-- 
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
	-- Leonard Cohen, from "Anthem"
--
Lee A. Hart  814 8th Ave N  Sartell MN 56377  leeahart_at_earthlink.net

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