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62

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 ...


42

To print an area of 7.5 by 10 inches at 300 DPI requires 844K if it's kept as a single bitmapped image. Does it? Maybe. Then again one cold think of many simple ways (like RLL) to compress a rendered image fast and decompress it at a speed quite capable to keep up with the print-'head'. Obviously they were doing something clever to minimize the hardware ...


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

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 ...


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 ...


32

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, ...


28

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 ...


26

In addition to Raffzahn's usual excellent answer, a few important things to note: PCL still exists. You can (I do...) still write software that sends simple PCL commands to a printer to select fonts, print text, etc. Sending an entire page, of text, as a bitmap to a printer is the way GDI printers work - and is a Very Bad Thing. The original HP LaserJet ...


24

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 ...


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 ...


20

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

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. ...


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

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 ...


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

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 ...


13

This question is a near duplicate of 'How can I convert Epson escape codes to a more usable format?', which lists some suggestions for tools for managing Epson sequences, but I'll provide some more background and information as I understand it. The IBM ProPrinter uses the IBM Personal Printer Data Stream (PPDS) page description language, which is a character ...


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 ...


12

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


12

To add to the other answers: Under Windows and GEM, printer drivers could store the current page as a metafile and rasterize it repeatedly as a series of horizontal bands, each band being large enough to fit into printer memory. This was slower than sending the data directly to the printer (since each page had to be rasterized repeatedly) but allowed an ...


11

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" ...


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

They simply didn't let you send much of a bitmap The first HP LaserJet printers on the market required you send jobs via PCL language. The language was tuned to pretty much not let you do anything the printer couldn't handle. PCL for the whole page needed to fit in the very limited RAM. Needless to say, PostScript was out of the question on these early ...


11

If this is a plotter, it might be an electrostatic plotter. But it looks far more likely to be a blueprint copier (or heliographic copier) which isn't a computer device at all.


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 ...


10

The manual says nothing more than it can print 12 characters per second and it uses BUSY pin. Even if you have connected BUSY output to CTS input, and turned RTS/CTS handshaking on, there is still a possibility that one or two extra bytes are sent out on the data pin, because the serial string write happens as a single large block, and also the USB packets ...


10

This is a classic data conversion problem. I have done similar things many times over the years with both parallel and serial printer ports and a variety of different operating systems. The other answer focused on actual formatting of the data, which is a real issue. I will discuss the actual transfer process: The two machines have to agree on communication ...


9

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 ...


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