Search found 176 matches

by ijabbott
Sun Jun 28, 2020 5:55 pm
Forum: Discuss!
Topic: Use the IR of DM42(or any HP calculator) for commercial IR?
Replies: 24
Views: 1272

Re: Use the IR of DM42(or any HP calculator) for commercial IR?

Although i own a HP82240, I'm experimenting to create a RedEye to serial interface using eighter a microcontroller or an FPGA (trying both paths) The Idea is to hookup small ticket printers i found in my junkbox. It'l take some time to get results but if you are interested i'll drop some posts late...
by ijabbott
Wed Jun 24, 2020 9:55 pm
Forum: Discuss!
Topic: Torr and mmHg ??
Replies: 30
Views: 766

Re: Torr and mmHg ??

... NIST throws away the digits saying compressibility of mercury is varying. But at the same time they also don't chop off c's digits because of uncertainty to the medium ... Not sure I got your point. What c are you talking about? :? The c I know is speed of light in vacuum - no medium per defini...
by ijabbott
Wed Jun 24, 2020 9:42 pm
Forum: Usage tips, tricks and problem reports
Topic: Thoughts on DM42 User Manual
Replies: 3
Views: 2316

Re: Thoughts on DM42 User Manual

There is a PDF scan of the HP-42S Owner's Manual, plus a PDF scan of the HP-42S Programming Examples and Techniques books linked to from the SwissMicros Models page. They are more far more comprehensive than the "alternative" manual. Not quite as nice as a paper manual. I was lucky enough to get a p...
by ijabbott
Wed Jun 10, 2020 7:52 pm
Forum: DM42
Topic: DM42 and accuracy
Replies: 24
Views: 1220

Re: DM42 and accuracy

michel.lample wrote:
Wed Jun 10, 2020 12:36 pm
Does the DM42 (Free42) still use the CORDIC algorithm for exponentiation calculations, as do many hp calculators?
No, that's like going back to the 1970s when saving register / memory space was far more important than saving time.
by ijabbott
Tue Jun 02, 2020 7:47 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42 arrived today! Stack layout?
Replies: 35
Views: 1427

Re: DM42 arrived today! Stack layout?

I use Google Chrome on an x86-64 Debian Linux machine and haven't encountered any problems on the SM forum. Thanks @ijabbott, that's the info I was looking for. It seems the problem is isolated to the version of Chromium that's compiled for ARM processors (all Raspberry Pi's utilise ARM processors)...
by ijabbott
Tue Jun 02, 2020 8:02 am
Forum: Usage tips, tricks and problem reports
Topic: DM42 arrived today! Stack layout?
Replies: 35
Views: 1427

Re: DM42 arrived today! Stack layout?

Talking of Linux. Does anybody else find that certain forum pages crash Chromium? I've had to install Firefox on all my Linux boxes simply so I can view the SM forum glitch free. I suspect that it's something to do with certain image embeds. It's no biggie as I have a workaround, but the behaviour ...
by ijabbott
Sun Apr 12, 2020 11:55 pm
Forum: Software Library
Topic: RTC Calibration program
Replies: 32
Views: 13855

Re: RTC Calibration program

Does anyone know at what point the ppm display under Setup — Settings gets updated, after changing the rtccalib.cfg file? I've just edited my file, changing from -21 to -22, but the display is still showing -21ppm. I've double-checked the file content (on a PC), turned the DM42 off/on a few times: ...
by ijabbott
Sat Apr 11, 2020 4:32 pm
Forum: OFFIMG library
Topic: The Manchester Bee
Replies: 1
Views: 608

The Manchester Bee

The worker bee has been an emblem of the city of Manchester in the UK for over 150 years, representing its industrial heritage.

This image is based on one registered by Manchester City Council.

manc_bee.bmp
The Manchester Bee
manc_bee.bmp (12.31 KiB) Viewed 608 times
by ijabbott
Sat Apr 11, 2020 2:10 pm
Forum: OFFIMG library
Topic: Dutch Lion
Replies: 24
Views: 2326

Re: Dutch Lion

Here's my attempt at the Welsh flag, based on the SVG in Wikimedia Commons. In Inkscape, I changed the colour of the grass to 25% grey and the colour of the dragron to 50% grey, and exported to a PNG of 400x240. In The Gimp, I converted to 1-bit black and white in pattern mode, touched up some stray...
by ijabbott
Sat Feb 01, 2020 8:37 pm
Forum: Hardware issues
Topic: BAT indicator stuck on
Replies: 19
Views: 3590

Re: BAT indicator stuck on

Also check the Vdd value on the DMCP Self Test Diagnostics page. I think it should be reasonably close to the battery potential in millivolts, except when powered by USB. In any case, it's more info for diagnosing the fault. I had noticed that Vdd was odd (1221) yesterday, so assumed it wasn't what...