2

Although it would have absolutely beaten the hardware to death, did anyone ever try to write a graphics driver for daisy wheel printers that would use the period symbol to painstakingly construct a graphical image, using micro-step platen and printhead movements?

Due to the speed limitations of the printhead solenoid, such an image would likely have taken 10 times longer to produce than on a 9-pin dot matrix printer, and there is the possibility of damaging the period symbol by over-flexing the wheel support arm. It would be prohibitively expensive with single-use carbon ribbons, and might damage looped fabric ribbons.

But... was it possible and did anyone ever do this?

7

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 early retirement, and you wanted to use your most faded (fabric) ribbons for that torture. If I remember right, it took several hours to print a 630x350 EGA picture with 4x4 (or 2x2? can't remember) dithering. 300 Baud serial didn't help that much on print speed as well.

You could set the horizontal motion index in 1/120", and the vertical VMI in 1/48", which only allowed printing of pictures turned around by 90°.

  • "Saved from Dump in the late 80s" might be an important the clue here. Though, nice hack :)) – Raffzahn Jan 11 at 19:14
  • 2
    @Raffzahn Well, a brand-new 630 cost roughly $2000 in 1985 - You really wouldn't want it to undergo such a torture. I really can't remember well, but think I got it pretty late, in the early 90ies. – tofro Jan 11 at 19:21
  • On the other hand, a Diablo 630 is built like a tank - It's probably hard to break it at all. Mine didn't break until the mid-2000s whan I moved house and had to get rid of it – tofro Jan 14 at 14:31
5

Yes - when at school I wrote a program for the Amstrad PCW that would do this. It's available for download as DSHOWSEA.COM from http://www.seasip.info/Cpm/software/amstrad.html .

The only test I ran was on my geography master's printer: a simple drawing of rectangles. With the dots at their closest spacing, it chewed up the paper rather.

2

Depends on the printer. Also keep in mind, daisy wheel printers aren't anything from before dot matrix, but rather of the same time frame, in general even later. Dot matrix ruled the 70s, while daisy wheels did had their peak during the 80s, until laser took off.

  • To start with, not every daisy wheel printer could be positioned (or fed) in size of a dot.

  • Next, wear would be outrageous

  • A way better and faster printing would be done using more symbols

  • Similar, using density of types and multiple strikes produce a way better picture

  • And last but not least, who would waste much time to write a driver to wear down a very expensive printer when a cheap dot matrix printer could do a better job?

Having said this, of course have type based printers used for (simple) graphs and drivers have been available, usually in fixed pitch mode.

  • 1
    I wonder how well a daisy wheel printer could have performed for graphics if one had a wheel containing various combinations of dots? For example, if one used 15 characters for vertical, horizontal, and diagonal lines that were 1-5 dots long, that would allow a major performance boost for many kinds of graphics. – supercat Jan 11 at 20:09
  • And there were definitely text-based graphics done on mainframe line printers, essentially using each character as a pixel with the coverage of the character (@ > X > I > , > . etc.) roughly corresponding to an intensity. See Mona Lisa – manassehkatz Jan 11 at 20:58
  • @manassehkatz Isn't that what I mentioned in my 4th point about using type density? – Raffzahn Jan 11 at 21:02
  • 1
    Sort of except you didn't say it's actually a thing, just a possibility. – manassehkatz Jan 11 at 21:39
  • 1
    @supercat All daisywheel printers I know regulate hammer impact based on the size of the printed character. This is normally encoded in the daisywheel itself by different spoke forms based on the character area (thus different resistance to the hammer impact). Otherwise, dots would be ending up engraved while "W" or "M" would be too light. – tofro Jan 13 at 16:23

Your Answer

By clicking "Post Your Answer", you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.