23 Dec
2024
23 Dec
'24
2:20 p.m.
On 2024-12-23 17:10, Van Snyder via cctalk wrote:
On Sun, 2024-12-22 at 22:26 -0600, jim stephens via
cctalk wrote:
From what I recall customers might have several different forms and
they might not be all the same length, so they would need a different
tape for each form length at least. The way it would work is a brush
would look for a hole in the tape and if it did not find a hole it would
skip until there was no more forms. This kind of run away was caused by
A) improper punching of the tape, B) putting the tape on wrong or C)
not loading the brushes that look for the hole after putting on a tape.
Twelve channels does seem excessive but would make the skip function
very flexable and using skip intelligently could greatly increase
throughput.
I never serviced 1403 saw lots of them, I did service 3203 which using
the same print trains, but used an electronic skip setup and 4245 which
was basically the same printer as 3203 but was a belt printer instead of
a train.
Paul.
The fun story I have was from when I was playing
one night and had
accidentally done a skip to channel, 12, which on our printer had no
stops, so it would jet paper out as fast as it could go.
The 1403 has a carriage
control tape loop. It's about two inches wide,
mounted at the top right. Each row corresponds to one print line. There
are twelve columns along the tape, called "channels." Channel 1 is "top
of form." That's the one the carriage skips to when you push the
"carriage skip" button on the printer, or execute the "skip to channel
1" instruction in the 1401 (I don't know the 360 instruction). You can
add punches in any other columns, for example you might want to skip to
channel 3, four lines down the page, after printing a header. Maybe if
you're printing statements or invoices you might want to skip to
channel 5 to print the customer's address, and channel 7 to print the
details etc. On the 1401, channel 12 is usually used to detect the
bottom of the page. There's an instruction to ask if the printer is at
column 12, called "branch if carriage overflow." But you can skip to
any channel, so "skip to channel 12" would work. Indeed, that might be
used to print footers, which have been what that program was trying to
do.
Why so many channels? It seems unlikely that any program would want to
have twelve different carriage positions. But you could reserve channel
1 for top of page, and twelve for bottom of page, and then use the
other odd ones for one program, and even ones for another program, so
you wouldn't need to change carriage tapes.