Talk:Line printer

Needs a picture[edit]

This article needs a picture. Somebody must have a public-domain picture of a line printer. --John Nagle (talk) 16:37, 14 May 2009 (UTC)[reply]

Done. --John Nagle (talk) 16:44, 14 May 2009 (UTC)[reply]

Typeface?[edit]

What typeface was used on the early line printers? I think there is a computer font derived from the line printer era. Does anyone know?--DThomsen8 (talk) 12:38, 27 October 2009 (UTC)[reply]

Often, 32 characters, uppercase only. I remember lineprinters. One job was with a toothbrush and some meths cleaning ribbon fluff and old ink from the drum around the characters and inside hollow characters such as 0 and O and 8. And nuisances such as a line of text printing astride the folds in the lineprinter paper. Anthony Appleyard (talk) 22:55, 14 December 2017 (UTC)[reply]

Print Samples[edit]

I'd like to see print samples from the various types of printers, especially a bit out of alignment, as each type of printer exhibited it's own unique registration problems (wavy lines, character clipping, etc.) 72.228.32.170 (talk) 12:35, 12 January 2011 (UTC)[reply]

Paper (forms) handling[edit]

"Many printers supported ASA carriage control characters..."
Really? I worked on a number of line printer drivers across a couple of OS's, and never saw one that implemented ASA carriage control characters in the printer. The conversion of ASA carriage control characters was always in the FORTRAN I/O library or provided in a post processing filter. 81.187.162.106 (talk) 05:42, 29 December 2011 (UTC)[reply]

Another type of drum printer?[edit]

Back in the late '60s I was on a tour of the Selfridge Air National Guard Base. In the "command center," where they had taped newspapers over some equipment to hide it from us, there was a line printer in use, and I was fascinated. Its basic construction was what is described as a drum printer, but I have a distinct memory of the entire cylinder moving to strike the paper, not the other way around. Did some of them work that way, or is my memory flawed? PapayaSF (talk) 20:55, 31 August 2014 (UTC)[reply]

The drum spins about its horizontal axis. I think it would be too heavy to move it back and forth too. The printers with half the number of print heads which move the hammer bank back a forth often result in the whole printer moving back and forth in the opposite sense to some degree, because the hammer bank is also quite heavy and the motion shakes the whole printer. Sadg4000 (talk) 18:49, 30 January 2015 (UTC)[reply]

What is the logic of this?[edit]

Often the character sequences are staggered around the drum, shifting with each column. This obviates the situation whereby all of the hammers fire simultaneously when printing a line that consists of the same character in all columns, such as a complete line of dashes ("----").

Why would having all the hammers firing simultaneously be bad? ZFT (talk) 03:39, 28 November 2017 (UTC)[reply]

Would it cause it to jam? ZFT (talk) 03:40, 28 November 2017 (UTC)[reply]

Firing each hammer takes a large electromagnet, with a high energy pulse. Firing them all at once causes excessive current draw. T bonham (talk) 08:53, 17 March 2018 (UTC)[reply]

many other systems call their printing devices "LP", "LPT", whether these devices are in fact line printers or other types of printers[edit]

That is because the term "line printer" was used to distinguish between a printer that printed one line at a time, and a printer that printed one page at a time. Character printers naturally fall into the "line" side of that divide, not the "page" side. — Preceding unsigned comment added by 121.200.27.15 (talk) 03:45, 16 December 2020 (UTC)[reply]

"Line printer" was originally distinguished from "character printer." Page printers came much later. Peter Flass (talk) 09:06, 17 December 2020 (UTC)[reply]

Gutenberg's printing press was a 'page' printer. The term 'line printer' was invented to distinguish line printers from ordinary printing presses, Roneograph, Mimeograph and other existing print technologies. — Preceding unsigned comment added by 121.200.27.15 (talk) 03:16, 19 October 2021 (UTC)[reply]

overprinting "art"[edit]

I know it's not too important, but some people produced a kind of "art" by sending more CR characters than LF characters (or the equivalent in EBCDIC or whatever) so that some lines could be overprinted. I vaguely remember Snoopy calendars being printed out in the one academic computing center I knew... AnonMoos (talk) 06:10, 10 June 2023 (UTC)[reply]

Might be worth a paragraph. Peter Flass (talk) 10:21, 10 June 2023 (UTC)[reply]

I was hoping someone would have some solid information; then we could decide what to include in the article. AnonMoos (talk) 12:36, 10 June 2023 (UTC)[reply]

I recently found on my computer's hard drive a message posted to Usenet newsgroup "alt.folklore.computers" on "23 Jun 91 13:50:37 GMT" by Charlie Gibbs through a British Columbia internet provider mindlink, with subject line "Line printer art available for FTP download" which goes into some of the details. I won't copy the whole message, which would be a copyright violation as well as containing lots of info on an anonymous FTP site which probably doesn't exist any more, but here are a few details:

"Records are variable length to a maximum of 133 bytes... The first byte of each record is a standard FORTRAN carriage control character, which can be one of the following:

        blank - single space before printing
        0     - double space before printing
        -     - triple space before printing
        +     - suppress spacing (overprints the previous line)
        1     - skip to a new page before printing

"The photo* files were digitized at Princeton University in 1973 by Samuel P. Harbison. To get the desired shading, each line is overprinted five or six times."

Topics of the various line-printer art files include "Assorted calendar girls", "Lots of Peanuts pictures", "Albert Einstein" etc. etc. AnonMoos (talk) 00:49, 31 July 2023 (UTC)[reply]

P.S. I just now had the idea of Googling the phrase "digitized at Princeton University in 1973 by Samuel P. Harbison" and turned up the following URL: http://q7.neurotica.com/Oldtech/ASCII/ (somewhat mistitled, since EBCDIC was the main character set used on ca. 1970 IBM mainframes and printers, as Harbison mentions...). AnonMoos (talk) 01:05, 31 July 2023 (UTC)[reply]

On a serial printer it would be some combination of CR, LF and NL, but on a line printer it would be by carriage control. Also, a lot of printer art did not use overprinting.

Did the Alfred E. Neuman picture from MAD use overprinting? -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 08:26, 31 July 2023 (UTC)[reply]

The file http://www.pdp8online.com/ftp/ascii_art/ppt/CONTENTS says that the ZIP files at http://www.pdp8online.com/ftp/ascii_art/ppt/ contain something called ALFRED1, but I don't feel like downloading and looking at it now... AnonMoos (talk) 10:24, 31 July 2023 (UTC)[reply]

Also, the letters column of the July 1974 issue of Mad magazine reproduced a line-printer art version of a Don Martin cartoon-character head... AnonMoos (talk) 10:24, 25 August 2023 (UTC)[reply]