13 Jul
2012
13 Jul
'12
11:19 a.m.
On Thu, 12 Jul 2012, Alexey Toptygin wrote:
One of the most common file formats for PCB production is known as a
'Gerber file'[1] I assume this was originally data to be sent to a
photoplotter or similar made by said compent.
[1] for some unknown reason, engineers often corrupt that to 'gerbil
file' ;-)
It talks about a Gerber SuperSprint plotter that
has GTP244-1 and GTP293-1
cards in it. Perhaps your card is from a proprietary expansion bus in this
plotter?
I don't know anything about their product line. But, as a nostalgic old fart, . . . I did a little time at GSFC SSDC (Bldg
26) on "the
etch-a-sketch" - A Gerber Data Digitizer that consisted of a light board
about 2 feet square, with two big knobs to turn to move cross-hairs.
When you had them where you wanted, you hit a foot-pedal and an 026 punch
next to it punched two three digit numbers for the coordinates.
Soounds...fun.
Incidentally, about your comment on a teach who thoguth $\pi$ was exactly
22/7. The preface for a book called 'Foundations of Wireless' (I am
lookign at the 3rd edition, 1943 reprint). contains the following :
'In particular "$\pi$" (read as "pi") is always used for the ratio
of the
circumference of a circle to its diameter; it is mentioend here because
its meaning is almost always taken for granted. The corresponding
numerical value is 3.1416 approximately (the decimal never ends), or
about 22/7"
Yor teacher should have read said book :-)
-tony