smaller HP 82166A with 32-pin connector

[Klaus Overhage]

Many thanks to Dave Frederickson and KimH for their background information on TTTL ICs. According to my multimeter, only 4 mA flow from the output of the 7474 through the red LED and is therefore within the permitted range for an LS version. I am surprised how bright it shines with the little current. I found Jerry Walker's YouTube video about the "Logic IC Pitfalls" very instructive and understandable. That's why I immediately subscribed to the channel.

pyILPER contains a simulation of the HP-7470A plotter and can save the drawn image as a PDF. I wanted to try that out with the HP-41 BIRTH program from J-F Garnier. So as an intermediate step, a version for the Canon X-710 that uses the PANAME ROM was created. Since the plotter commands contained in this ROM are very similar to those of the HP plotter module, the changeover is almost done. And I wanted to know how it changed the running time: Instead of: 10 minutes and 34 seconds, the PANAME-Version needed only 9 minutes and 54 seconds for the 19071969 image.

The version with the plotter module took 15 minutes with the simulated HP-7470A, probably because of the conversion to a larger image. But the result looks really fantastic. And the generated PDF's are tiny! See for yourself: