13 Jun
2006
13 Jun
'06
8:22 a.m.
Topic came up on a local newsgroup - anyone know what the typical speed of a
chain printer was/is? I can't find any hard figures online - all the info
about chain printers seems to just say they were "high speed" and that's
it.
Just curious!
cheers
Jules
13 Jun
13 Jun
8:46 a.m.
Topic came up on a local newsgroup - anyone know what the typical speed of
a
chain printer was/is? I can't find any hard
figures online - all the info
about chain printers seems to just say they were "high speed" and that's
it.
1:04 p.m.
At 02:46 PM 6/13/06 +0200, you wrote:
This question is not easy to answer.
The IBM 1403 printer came in at least 2 versions : a 1000 lpm and a 300 lpm.
However, the effective speed depended on what was being printed, as the
chains could be different. Typically, a chain had more E's then Y's, more
A's then P's, etc.
Interesting, The chain printers that I worked on all had the exact same
number of different characters. Depending on the number of characters in
the character set that was used on that partticular printer they usually
had 2 or 3 COMPLETE character sets. IIRC there were 196 positions per belt
and the characters sets that we normalled used were either 64 char/set or
96 char/set. Burroughs had a number of different character sets available
for the printers but in 2+ years that I worked for them I don't recall ever
seeing any used except those two.
Joe
I also recall a numeric-only version, which could do up
Topic came up on a local newsgroup - anyone know what the typical speed of
a
chain printer was/is? I can't find any hard
figures online - all the info
about chain printers seems to just say they were "high speed" and that's
it.
to 2000 lpm, and I've heard about (but never seen)
a Braille version
Nico
14 Jun
14 Jun
1:19 a.m.
>This question is not easy to answer.
>The IBM 1403 printer came in at least 2 versions : a 1000 lpm and a 300
lpm.
However, the
effective speed depended on what was being printed, as the
chains could be different. Typically, a chain had more E's then Y's, more
A's then P's, etc.
Interesting, The chain printers that I worked on all had the exact same
number of different characters. Depending on the number of characters in
the character set that was used on that partticular printer they usually
had 2 or 3 COMPLETE character sets.
1:37 p.m.
At 07:19 AM 6/14/06 +0200, you wrote:
Chains could be (and were) made to order (more or less),
The chains in the ODEC printers weren't made to order. Well maybe they
were, depending on your definition of 'made to order'. The chains used in
the ODEC printers were basicly big rubber bands and each character was a
separate "slug" that clipped onto the band. The characters could be ordered
in sets and IIRC we also ordered individual characters*. We could install
complete character sets or just individual characters as needed.
*The slugs had a bad habit of breaking the clips that held them to the
belt and when they did the slugs shoot out like a bullet! The printer used
a metal proximatity sensor to count each slug as it went by and that's how
it knew when to fire the appropriate print hammer. But when it lost a slug,
all the following caharacters were shifted down by one and you got garbled
print. for example, if the "i" slug came off "The quick brown fox"
became
"The qujdl cspxo gpy"!
Joe
>This
question is not easy to answer.
>The IBM 1403 printer came in at least 2 versions : a 1000 lpm and a 300
lpm.
However,
the effective speed depended on what was being printed, as the
chains could be different. Typically, a chain had more E's then Y's, more
A's then P's, etc.
Interesting, The chain printers that I worked on all had the exact same
number of different characters. Depending on the number of characters in
the character set that was used on that partticular printer they usually
had 2 or 3 COMPLETE character sets.
15 Jun
15 Jun
2:07 a.m.
From: "Joe R." <rigdonj at cfl.rr.com>
The chains in the ODEC printers weren't made to order. Well maybe they
were, depending on your definition of 'made to order'.
It's a long time ago I saw a 1403, but if I'm not mistaken, the national
characters like ? ? ? were on the same slug. So I must modify my statement
to "slugs were made to order". However, this implied that the
firmware"connecting" the chain to the character set (I dont know how to
phrase that in a more intelligent way), had to be modified too.
Now that I come to think of it, we had a special chain for OCR. This one was
used for writing bonus checks at the end of the year.
Nico
>> Interesting, The chain printers that I
worked on all had the exact
same
>> number of different characters. Depending on
the number of characters
in
>> the character set that was used on that
partticular printer they
usually
had 2 or 3 COMPLETE character sets.
Chains could be (and were) made to order (more or less), 
17 Jul
17 Jul
8:30 a.m.
I was told 60 LPS (so 3600 LPM) for the IBM 3262 belt printer that was
attached to the AS/400 (don't know what model, but it was one of the
oldest 3-19"-racks-full ones) in my first ever IT job.
No idea whether that's accurate, mind... what I do know is that the
thing could basically consume boxes of paper as fast as you could load
them into it :-)
13 Jun
13 Jun
11:08 a.m.
On 6/13/2006 at 12:22 PM Jules Richardson wrote:
Topic came up on a local newsgroup - anyone know what
the typical speed
of a
chain printer was/is? I can't find any hard figures online - all the info
about chain printers seems to just say they were "high speed" and that's
it.
It depended entirely on what was being printed. There were worst-and-best
case patterns. Consider the way a chain printer worked.
You have a spinning chain, a wide ribbon, the paper and (usually about 132)
hammers all making a sandwich. When a character in the chain is at the
right position, the hammer at that position fires and bangs the paper
against the ribbon backed by the type slug. Now, if the pattern being
printed matches the order of characters on the chain (or the non-matching
characters are spaces), you're all done and the paper advances. If not,
then the paper has to wait until the proper characters come around to their
respective positions.
Clearly, the number of different characters in the chain is going to affect
how many times they can be repeated in the chain; a chain containing
lower-case characters in addition to uppercase is going to, on the average,
print more slowly than a chain with just uppercase. Similarly, the
manufacturer may have decided that some characters are so rarely used that
they merit only one or two occurrences, while more frequently-used
characters merit more frequent repetitions. Ordering of the characters on
the chain also matters; placing a "U" next to a "Q" is a good idea.
Most manufacturers give a number based on the average printing speed of a
printer and 1500 LPM was about par for the high-speed models with "easy"
lines going considerably faster.. But with the wrong type chain/train and
pathological data, speed can drop as low as 60 LPM or so. Other factors
could reduce printing speed, such as carriage control--when we printed
documentation, we bolded characters by overstriking, essentially forcing
the printer to print the same line 2 or 3 times.
If you think about it, the chain/train printer is a perfect example of
early parallel processing, although it was rarely stated as such.
Cheers,
Chuck
11:37 a.m.
Forgot to mention that chain/train printers weren't the only type that
worked like this. Teletype had a printer that used an embossed steel band
instead of a chain (Model 40?) that worked the same way, although at a
lower speed. One used to be able to pick those up pretty cheaply on the
surplus market; if you had a lot of tractor-feed wide-carriage printing to
do from a PeeCee or other micro, it was an attractive alternative to
daisywheel and early dot-matrix printers.
I don't know if any still are in use--without a sound hood they could be
very noisy. I do have circuit diagrams and maintenance documentation on
one if anyone needs it.
Cheers,
Chuck
11:50 a.m.
I used to do some DP on a PDP-8 that originally had an LA-36.
Although I cannot remember for sure if it was driven by the PDP-8, we
later switched to a Centronics (IIRC) 600 LPM band printer (at some
point the computer was replaced, although I cannot recall what it was
replaced with). This was, of course, a dramatic improvement over the
LA-36.
However, cleaning the band was a great way to risk losing fingers.
Every so many hours we had to remove the band and clean the paper dust
out. We found that rubber dishwashing gloves worked well. The band
wasn't sharp enough to cut them, they kept the fluid off your fingers,
and gave you good traction for handling the band.
--jc
Chuck Guzis wrote:
Forgot to mention that chain/train printers
weren't the only type that
worked like this. Teletype had a printer that used an embossed steel band
instead of a chain (Model 40?) that worked the same way, although at a
lower speed. One used to be able to pick those up pretty cheaply on the
surplus market; if you had a lot of tractor-feed wide-carriage printing to
do from a PeeCee or other micro, it was an attractive alternative to
daisywheel and early dot-matrix printers.
I don't know if any still are in use--without a sound hood they could be
very noisy. I do have circuit diagrams and maintenance documentation on
one if anyone needs it.
Cheers,
Chuck
1:07 p.m.
At 08:08 AM 6/13/06 -0700, you wrote:
On 6/13/2006 at 12:22 PM Jules Richardson wrote:
That's not quite the way that the chain printers that I worked on worked.
The ODEC printers feed the chain from the left and the characters where in
ASCII order. The data for the entire line to be printed was feed into a
buffer and whenever a character on the chain rotated to a position where it
matched the character to be printed then the hammer for that position
fired. The result was the the hammer firing was very erratic and the
printer made a hell of a noise. But it could print an entire line in one
pass of a character set even if you printed nothing but the sme character
in every print position. Of course if you printed somehting like "GFEDCBA"
then you got a lot of matches and a lot of hammers firing at the same
instant! Situations like that were another thing that made these printers
so noisy, there was no rythum at all to the way that the hammers fired.
Each chain usually had 2 or 3 complete sets of characters. Worst case for
one of these printers would be where you printed the same character in
every position.
FWIW print speed was VERY different depending on the width of the paper,
order of characters on the printed line, the maximum number of occurances
of the same character in a line and a host of other factors.
Joe
If not,
Topic came up on a local newsgroup - anyone know
what the typical speed
of a
chain printer was/is? I can't find any hard figures online - all the info
about chain printers seems to just say they were "high speed" and that's
it.
It depended entirely on what was being printed. There were worst-and-best
case patterns. Consider the way a chain printer worked.
You have a spinning chain, a wide ribbon, the paper and (usually about 132)
hammers all making a sandwich. When a character in the chain is at the
right position, the hammer at that position fires and bangs the paper
against the ribbon backed by the type slug. Now, if the pattern being
printed matches the order of characters on the chain (or the non-matching
characters are spaces), you're all done and the paper advances. then the paper has to wait until the proper characters
come around to their
respective positions.
Clearly, the number of different characters in the chain is going to affect
how many times they can be repeated in the chain; a chain containing
lower-case characters in addition to uppercase is going to, on the average,
print more slowly than a chain with just uppercase. Similarly, the
manufacturer may have decided that some characters are so rarely used that
they merit only one or two occurrences, while more frequently-used
characters merit more frequent repetitions. Ordering of the characters on
the chain also matters; placing a "U" next to a "Q" is a good idea.
Most manufacturers give a number based on the average printing speed of a
printer and 1500 LPM was about par for the high-speed models with "easy"
lines going considerably faster.. But with the wrong type chain/train and
pathological data, speed can drop as low as 60 LPM or so. Other factors
could reduce printing speed, such as carriage control--when we printed
documentation, we bolded characters by overstriking, essentially forcing
the printer to print the same line 2 or 3 times.
If you think about it, the chain/train printer is a perfect example of
early parallel processing, although it was rarely stated as such.
Cheers,
Chuck
6 p.m.
On 6/13/2006 at 5:07 PM Joe R. wrote:
Chuck, before his first cuppa said:
worked.
against the
ribbon backed by the type slug. Now, if the pattern being
printed matches the order of characters on the chain (or the non-matching
characters are spaces), you're all done and the paper advances.
That's not quite the way that the chain printers that I worked on The ODEC printers feed the chain from the left and the
characters where in
ASCII order.
We're actually saying the same thing--it's just that I forgot to say
"matches the order of characters on the chain (or the non-matching
characters are spaces), you've printed the line in one swell foop, you're
all done and the paper advances. Otherwise, the unprinted positions wait
for their respective characters to arrive..." Sometimes, I don't do so
well translating the pictures in my head to words. :(
One could always hear a job banner being printed because of the peculiar
pattern of repeated characters printed across the page perf used as a
visible divider (if you looked at a stack of job output, you could pick out
individual jobs because normal output didn't print over the perfs. Made
life easy for the I/O clerks.)
Similarly, you always knew when a CE was working on the printer because of
the distinctive sound of the diagnostic test patterns.
Type slugs wore at different rates, depending on the application. Since we
were always printing lots of deadstart dumps (a Cyber 74 with 4M words of
ECS could easily occupy most of a box of paper), the "zeroes" got fuzzy far
faster than any other character.
I never understood how the band printer uses dealt with this (other than
replacing the band regularly).
Maybe it's a trick of the eye, but the old drum printers often exhibited a
lot of vertical misalignment of characters, making for wavy lines and very
annoying reading. Curiously, the horizontal misalignment of characters in
chain, train and band printers didn't seem to matter nearly as much.
I remember that the Univac 1108 hardware manuals were drum printed and then
reproduced and were darned near illegible after a couple of hours of
miserable reading. By comparison, 1403 output was pristine.
Cheers,
Chuck
1:23 p.m.
Chuck Guzis wrote:
Most manufacturers give a number based on the average
printing speed of a
printer and 1500 LPM was about par for the high-speed models with "easy"
lines going considerably faster..
that's probably the important bit... with what, something like 66 lines per
page - so a shade over 20 pages per minute.
Not bad, considering the age of the technology; I bet the average modern
inkjet only does about 1/5th of that, and lots of laser printers still won't
match it (not that you'd necessarily want a chain printer in the home :-)
cheers
Jules
12:31 p.m.
Jules Richardson wrote:
Topic came up on a local newsgroup - anyone know what the typical speed
of a chain printer was/is? I can't find any hard figures online - all
the info about chain printers seems to just say they were "high speed"
and that's it.
Compared to a TTY any other printer is high speed. :)
12:46 p.m.
Jules,
When I worked for Burroughs in 1977 they had three different models of
chain printers. They were all made by ODEC (Ocean Data Electronics Corp.)
and were basicly the same except for the print speed. The two most common
models were 150 and 300 characters/second. I'm pretty sure that the third
model was 600 c/s but it was much less common. In fact, I'm not sure that I
ever saw one.
Joe
At 12:22 PM 6/13/06 +0000, you wrote:
Topic came up on a local newsgroup - anyone know what the typical speed of a
chain printer was/is? I can't find any hard figures online - all the info
about chain printers seems to just say they were "high speed" and that's
it.
Just curious!
cheers
Jules
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bfranchuk＠jetnet.ab.ca -
cclist＠sydex.com -
jcwren＠jcwren.com -
julesrichardsonuk＠yahoo.co.uk -
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nico＠farumdata.dk -
rigdonj＠cfl.rr.com