29 Dec
2002
29 Dec
'02
3:39 p.m.
Fred Cisin (XenoSoft) wrote:
On Sun, 29 Dec 2002, Sellam Ismail wrote:
And I forgot to mention the really funky codes
that combine two of the 12,
11, 0 zones and multiple rows to form special characters (like 12-0-1-8-9
for NUL in standard IBM EBCDIC).
And don't forget the silliness of punching graphic images on cards. I was
showing punch cards to my OS class, including portapunch (right after a
certain Florida election). I wanted to show them some of the variations,
such as round-hole and other sizes (there are some great stories about
some of those!), and the only example of the half sized card that I had
was punched with holes making a picture of a hand giving the finger. Why not just read two columns, each of which is twelve
bits, pass that as
three bytes of raw binary, and then decode in the host machine?
I would read all 80 columns 16 bits each.
Remember often a blank column could be read
as a leading zero. One place to look for card
to ascii? encoding is old data books on mask
programable roms as that was a common use for
them.
Ben.