DM42 with homemade printer

Discussion around the Swiss Micros DM42 calculator.
Thomas Okken
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Re: DM42 with homemade printer

Post by Thomas Okken »

Can the DM42 send data to this printer at a rate that takes advantage of the line printer mechanism's speed, or is it limited to the 82240-compatible data rate?
Thomas Okken wrote:
Fri Oct 02, 2020 5:42 pm
Whether you want to include Turkey in the list of countries in Europe but not in the EU due to its tiny European portion is a matter of taste.
I shouldn't have dissed the European part of Turkey: apparently it's nine times the size of Luxembourg and home to 11 million people. Oops! :oops:
dk-
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Re: DM42 with homemade printer

Post by dk- »

Thomas Okken wrote:
Sat Oct 03, 2020 7:32 pm
Can the DM42 send data to this printer at a rate that takes advantage of the line printer mechanism's speed, or is it limited to the 82240-compatible data rate?
I don't know actually. The thermal printer I have is limited to 19200 baud, and however long it takes to print. I am also sending everything as bitmaps to get the correct font (and double width and double height) which might throttle the max speed. Good thing to test I suppose...
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ijabbott
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Re: DM42 with homemade printer

Post by ijabbott »

dk- wrote:
Sat Oct 03, 2020 1:34 pm
I had some time today to write some more code. I now have the code running on a single Arduino Uno and it uses the correct font! That is, as far as I could decipher from a printout. There might be some pixels wrong here and there on some of the characters.

So I have a request, can anyone who has a real HP printer help me out? It would be awesome if you could do a few self-tests (more than one since each print might not be perfect) and take a high resolution picture or scans of it and add to the thread? In return I will make sure that all my code will be available for free.
I should think that the graphical output of Christoph Gießelink's HP82240B Printer Simulator already uses accurate font information, and it includes the source code, so you could "borrow" the font bitmaps from that.
dk-
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Re: DM42 with homemade printer

Post by dk- »

ijabbott wrote:
Sat Oct 03, 2020 9:11 pm
I should think that the graphical output of Christoph Gießelink's HP82240B Printer Simulator already uses accurate font information, and it includes the source code, so you could "borrow" the font bitmaps from that.
I've already done the font, but thanks for the tip. I didn't want to take anyone elses code so I made the font from a printout myself.
dk-
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Re: DM42 with homemade printer

Post by dk- »

I've updated the repository (https://github.com/dankar/redeye) with a schematic, some notes on the schematic, and updated the code to correctly handle overflows (the printer will print the overflow character, same as the real HP printer).
BobVA
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Re: DM42 with homemade printer

Post by BobVA »

Excellent, thanks!

One feature that might be useful is a "text only" mode, which uses the printer module's native font. I've found that perfect for simple "adding machine" operations or program listings.

Just my opinion, of course, but I found the built-in font on the printer module I used is much easier to read / more attractive than the HP82240 font.

I may be making a virtue of a necessity though. My shoddy C++ programming skills makes full 82240 emulation an ulikely "aspirational goal" for me. :-)
reavy
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Re: DM42 with homemade printer

Post by reavy »

toml_12953 wrote:
Sun Sep 27, 2020 11:11 pm
... do you think an IR printer would enhance your enjoyment of the calculator?

If you can't already tell, I'm trying to get a feel for the market for an IR printer compatible with the SM calculators.

If SwissMicros or other company is seriously contemplating producing one, then I'd immediately stop my plans. I have no desire to take business away from anyone.

If not then I'll begin a development project which may or may not result in a shipping product.
I’m definitely interested. I too would prefer something new to complement my new DM-x calculators. Maybe a general interest thread is in order.
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