Author: scruss

Small things that make me happy …

Chebucto Community Net in Nova Scotia still has all its downloads and instructions for helping to get an Apple II (8 bit) & Apple IIGS (16 bit) online.

Colours for Mary

Colours for Mary

Colours for Mary

I was cleaning fountain pens just after I’d heard that Mary Pratt had died. The colours arising from a mundane task reminded me of Mary’s work. The light through the marmalade jar’s a little tip to Mary’s Jelly Shelf, which we saw at Halifax’s The Rooms exhibit in 2013.

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Comprehensive Uncle TechTip Simulator

Around 1988–1991 there was a weekly computer magazine in the UK called New Computer Express. This period coincided roughly with the time I was a freelance writer in the same field.

For childish reasons now lost to time, a group of us freelancers had a major hate-on for  NCE’s advice columnist. Writing under the name Uncle TechTip, this columnist seemed to answer most questions with something like “Hmm, I don’t know anything about _____. Maybe a reader can help?” Almost without fail, he’d have readers write in answers for next week’s issue.

Not realizing that Uncle TT’s economy of response was a sly precursor to crowdsourcing websites, the neophyte journo brigade were incensed by his lack of knowledge. One of us wrote an Uncle TechTip Simulator in BASIC, which I recreate from memory for your enjoyment:

10 CLS
15 PRINT " *** Uncle TechTip Simulator ***"
20 PRINT
25 INPUT "What is your question for Uncle TechTip";a$
30 PRINT
35 PRINT "Uncle TechTip's Answer: "
40 PRINT
45 PRINT "Hmm, I don't know anything about"
50 PRINT " ";a$;" ..."
55 PRINT "Maybe a reader can help?"

Using SI prefixes/multipliers in spreadsheets

Note: I’ve lightly tested this with Microsoft Excel (Windows 10), Excel Online, Google Sheets and LibreOffice Calc. It seems to work. Like all spreadsheet data conversions, please verify before trusting your PhD thesis tables to it …

Asked on the GTALUG mailing list the other week:

Does anybody know how to display and work with SI numbers like 10k or 
20M or 40G within LibreOffice?

I came up with the following formula, in this example for data in cell D3:

=IF(LEN(T(D3))=0, D3, CONVERT(VALUE(LEFT(D3, LEN(D3) - 1)),
    RIGHT(D3, 1) & "m", "m"))

which results in:

Input Value
1u 1.00E-06
10u 10.00E-06
100u 100.00E-06
1m 1.00E-03
10m 10.00E-03
100m 100.00E-03
1 1.00E+00
10 10.00E+00
100 100.00E+00
1k 1.00E+03
10k 10.00E+03
100k 100.00E+03
1M 1.00E+06

The right column is displayed in LibreOffice Calc’s newly(ish)-supported engineering notation.

This function works through creative (mis-)use of the CONVERT() function:

  1. if the argument is a numeric value, pass it through;
  2. if the argument is a string, return CONVERT(«numeric part», "«prefix»m", "m"). This is lightly misusing overloading the unit conversion function by going via metres, but it saves having a lookup table.

This function doesn’t work with IEC 60027-2 binary prefixes, but they’re silly and I wouldn’t be caught dead using ’em.

vase mode

I’m still a sucker for vase mode/spiral contour prints … this one made in OpenSCAD:

Thanks to Andrew at ProtoLab for the loan of the PrintrBot. I’ve got a demo at UofT on Wednesday, and my Reach 3D isn’t exactly portable. Yeah, I should probably get a cheap Monoprice printer to lug around to occasional demos, but I’d need to find a donor …