Hot answers tagged

60

As so often with basic measurements like this, the roots have been laid out way before today's computers, even before computers (non human that is) at all. From what I read, most line printers have 132 columns. Also, the VT-220 and presumably other terminals may be switched between 80 columns (that's a usual width) and 132 columns. The number is a result ...


40

The Epson MX-80, upon which many other printers were based, had nine round pins which were vertically spaced at 1/72" intervals. On such printers, the print head could generally move at two speeds, one twice the other. At high speed, a printer could place dots at 120dpi resolution, but could not strike two adjacent dots. At low speed, the resolution was ...


37

The paper I used in my dot-matrix printers (and still buy and use today) has 60g/m2 for the cheaper green-lined type and 70g/m2 for the pure white version. There is a rough guideline in the paper industry to calculate paper thickness from weight per square meter: t = 1.3 * wsqm / 1000 60g/m2 roughly ends up at 0.08mm, 70g/m2 around 0.09mm EDIT: Just ...


36

Fonts for text rendered to the screen or paper in a graphics mode would simply be data shipped with the application. If this was perceived to be non-copy-able, it is likely because it was not (obviously) in a standard font format, and perhaps intentionally obfuscated. It is also worth noting that VGA cards permitted relocating the text mode character ...


29

First, it may be good to know that the MX-80 did not feature a bitmap mode for graphics, but only 64 symbols. The MX-80 also used 7 bit encoding, so no room for 8 bit graphic data. It was the MX-80 Type II that included it. So while the name is used simply as MX-80, it's always the MX-80 Type II we're talking. Second, Just because some printer looked alike, ...


27

Basically, there were two options: Do it in hardware: Dot matrix printers were available in wide-carriage versions, so they could print A4 landscape / A3 portrait. Do it in software: Using the printer's bitmap mode, the computer would render the rotated letters in vertical stripes, corresponding to the printer's lines. This doesn't require all that much ...


23

There is an old carboard box that used to contain fanfold paper right next to me. Using the label on the box for the number of sheets and a ruler to measure the box, a stack of 2200 sheets was 7 1/2 inches thick, which is near enough 300 sheets per inch. or 0.085mm per sheet if you prefer those units. This would have been plain white paper, the stuff we ...


23

TL;DR; Typical dpi of dot matrix printers available in the 1980s Horizontal: 60, 72, 80, 90, 120, 240 and 360 dpi Vertical: 72 dpi for 8/9 pin and 120 dpi for 12/24 pin printers. Multiples thereof by printing a line twice. The Long Read: However, it's difficult to determine exactly where the individual pixels of the monochrome image lie... Which of ...


19

For the PC there was a specific program called, I believe, Sideways that did exactly this. It was targeted mostly towards spreadsheets (at least that's how I saw it most used). As I recall it essentially rendered the text output in to a graphic that was rotated 90 degrees, and then printed.


16

they save every program from needing its own separate encyclopedic knowledge of every printer on the market. But then came PostScript, the theory behind which was that you would prepare a printable file in a standard format For one, Postscript isn't a standard format printable file, but a standard format document description. It may (and does) contain many ...


15

DOS knows nothing about graphics fonts (mostly: it supports different display fonts which can be loaded using CHCP to change the display's code page, and some other minor details.) It was up to each program to come up with their own method of sending text and images to the printer, generally with the help of a printer driver that contained font metrics for ...


14

Speed Teletypes were not all limited to use over a modem. Many (e.g., the Model 43 - I had one of those) even had an RS232 compatible interface and could easily be used as a regular computer printer. But since most teletypes were designed for communications, and typical modems of the time were low speed, the teletypes themselves were low speed printers. ...


14

There would be no technical reason to not use all nine pins, but it doesn't really help either. Remember that the computer speaks to it using 8-bit bytes. Sending 9-bit wide data requires buffering and/or other relatively expensive processing to do the 9-to-8 conversion and back. The upside would be that printing 9 pixels wide would be 12.5% faster than 8 ...


13

The United States has its own paper sizes, two of which are 11"x17" ('ledger/tabloid') and 8.5"x11" ('letter'), which are similar to A3 and A4 and have the same sort of predominance. Early fixed-width font printers usually offered a 12 characters-per-inch typeface. 12*11 = 132; so 132 characters is the number you can fit on a landscape 'letter' page, or a ...


13

At that time, how did text programs, spreadsheets, and other tabular reporting applications output in Landscape to contemporary dot matrix printers? For businesses that needed wide printouts, it was common to buy a wide carriage (tabulator type) printer. For example, Epson not only sold the MX-80, but also the MX-100 with a wider carriage able to handle up ...


12

Looks like inverse polarity. The CR code is 015, 00001101 in binary. The codes for "=" and "y" are 075 and 171, 00111101 and 01111001 respectively. Note the sequence of four zeros in CR, and sequences of four ones in "=" and "y". With the inverse polarity, the character boundaries will depend on the speed with which they are sent because the start and the ...


12

Cost There are significant licensing costs and equipment costs. I'm sure PostScript needs quite a bit more RAM & processing than some of the lower levels of PCL and similar printer languages. As I noted in my answer on trackballs and elsewhere, even a small increase in cost can have a big impact on sales and/or profitability, particularly at the low end ...


11

PostScript was quite demanding. In the early days a PostScript printer might well be the most powerful computer in the building, hence expensive. University students ran jobs on the printer to get done faster. In a world where price is important, this was most likely the primary reason. Look at the cheapest printers available and check if they run ...


11

EscP2 language did specify a 9-pin mode: ESC ^ but it was not very efficient, a whole byte was needed just to send the 9th pixel. Epson reference manual


10

DOS itself did not manage them. Development environments used to ship with libraries that could support graphics modes, some with built-in font support. Some had vector fonts, some just blitted a dot matrix, favorably 8 pixels wide so one byte could encode one monochrome character scan line. The operating system contributed little to nothing. A popular ...


9

As a condensed answer: On a 9-pin printer (the cheaper kind), the physical pins might make a dot approximately one point (1/72") in diameter. The dots could be placed at 120dpi density and 1/240" precision horizontally, and (by three-pass printing) at 1/216" density and precision vertically. Graphics printing normally used only 8 of the pins; the ninth ...


8

I successfully got the RK-P400C printing from a serial console (minicom on Linux) today. Here's how to do it for future reference...;) The DB25 connector on the right side is a 25 pin serial port. At the top right of the typewriter there are sets of switches to select font and size, at the far right of those are two switches with the labels "KBI, KBII, EXT" ...


8

I used to have a Diablo 630 DWP saved from the dump. This did produce nice graphics using a dot character and micro spacing together with my AT compatible of that time. The whole procedure was, however, not very friendly to both ribbon and paper as you say, you had to reduce wheel impact (by retracting the solenoid) as much as possible to save both from ...


7

The assumptions of this question are at best misleading and maybe based on personal experience, but not the situation at the time cited. As requested I just pulled out the very second issue of Kilobaud Magazin of February 1977 (*1). Right at the beginning there is an ad on page 12 selling ASR33 starting at USD 840. Page 54 shows an ad offering an Olivetti ...


7

The teletype was not only the printer but for some old systems it was the only monitor for standard output. Having a CRT monitor made that function obsolete so that leaves only printing. The teletype was originally designed for copper line telephone network based text messaging. MS-DOS had no networking capabilities but you could install a modem in early ...


7

If the printer is offering an actual RS232 port, this should be identifiable by there being an RS232 level converter IC near the connector on its logic board: Usually, there will be a DS232/MAX232 or other MAX23x series IC, or a NEC D4711/UPD4711, or a combination of any of MC1488/MC1489/SN75188/SN75189/GD75189/GD75188/GD75232... This chip inverts the ...


6

I don't know if this is the "best" solution, but I have found applying Singer light sewing machine oil to a dried-out fabric printer ribbon appears to be effective. This oil is odorless. Amazon: https://www.amazon.com/dp/B000YZ1Y06 Apply sparingly a drop at a time, and then set the ribbon aside and allow it time to soak or it will make a mess on the paper ...


6

Fax machines used to use thermal paper by the pallet, and it is still commonly available wherever office supplies are sold (including amazon). While this will be wider (not, as the problem is with the cash register rolls, narrower) than what these vintage printers need, this problem can be fixed with a guide and a sharp knife (and in the worst case re-...


6

I don't know if I can say this for 100% certainty for every HP printer ever, but in general Hewlett Packard printers that support HP's own Page Control Language (PCL), which as far as I know is every one of them, has built-in fallback support for monospaced lineprinter mode when the device is first turned on. Generally all you need to do is spew raw text at ...


5

In the old days(tm) it was common to reink fabric ribbons for typewriters, in fact, the early ones where made that way. I kept using that practice during the 70s and 80s for daisy wheel and dot matrix printers. In theory ribbons could be reinked an unlimited time, but in reality wear on the fabric (too much movement due the hammer) limited this to like a ...


Only top voted, non community-wiki answers of a minimum length are eligible