On Tuesday, 10 November 2020 at 9:08:44 +1100, Dave Horsfall wrote:
On Mon, 9 Nov 2020, Greg 'groggy' Lehey
wrote:
The Qume printers seemed to have been the best
round 1980 when we used
them in our applications. In particular, a large choice of wheels and
fine-grained spacing. I forget how the spacing worked.
Presumably some sort of a table lookup, based on which character is about
to be hit? Or are you referring to the micro-spacing itself?
"Yes". As I said, I forget. I have a feeling that it must have been
explicit micro-spacing, since the machine didn't know anything about
the kind of daisy wheel that was fitted.
The golfball
console for the /360 was much earlier than that, like the
/360 itself. The model numbers I recall were 735, and the newer
generation 2731/2735. The last digit related to the carriage width
(11"/15").
I once had a fine collection of goofballs (as we called them); sadly lost
in a house move :-(
I was going to say "ditto", but I think I actually sold them along
with the 735.
Round the time
in question I bought a second-hand 735 machine. It had
an arcane interface that directly talked to the magnets. I built an
interface for it to a parallel port [...]
I'd like to know a bit more about that interface... You'd have to
control the carriage, roller, swivel/tilt/hit etc.
Yes, I'm trying to recall that too. The ball itself was controlled by
6 signals: Up 1, up 2 (for the 4 rows of characters), left 1, left 2,
left 2 (yes, twice) and right 5, for a total of 11 columns. But my
recollection was that I only had about 10 power transistors driving
the thing. I wish I had kept more details. Maybe there's something
amongst the useless junk in the shed.
How did you detect the BREAK key to get the 360's
attention and
unlock the keyboard?
I didn't. The 735 doesn't have a BREAK key. It was a typewriter, not
a teletype. I used it as a printer in addition to a normal glass TTY.
Greg
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