I had several boxes of punch cards from the early- to mid-70s, but I threw
them out circa 1990 because the printed text at the top had faded away. I
regret that now. I have only one punch card left, made at the Computer
History Museum in 1986, back when it was still in Boston.
Back in the day, AT&T and other companies sent a punch card along with
their bills. You were supposed to mail the card back with your payment.
My dad started receiving credit card bills for $0.00. He tried several
times to get this fixed, to no avail. I was an undergrad at the time. I
told him to send me the punch card that came with the bill. I would alter
it and send it back to him. He was then to write an explanation of the
billing problem on the back of the card and then mail it to the credit card
company. My alteration was to make an invalid overpunch so that the card
could not be read. The $0.00 bills stopped coming.
I later found out the cause of the $0.00 problem. It comes from use in a
COBOL program of a statement such as:
IF BALANCE IS NEGATIVE THEN <print bill>
Commercial financial information is commonly stored using scaled packed
decimal numbers. Packed decimal has a separate sign so there are two zero
values--zero with positive sign and zero with negative sign. In this case,
somehow the account balance was recorded as negative zero, and that tests
TRUE for IS NEGATIVE. The proper way to code this is:
IF BALANCE IS LESS THAN ZERO THEN <print bill>
-Paul W.
On Mon, Mar 10, 2025 at 10:17 PM Tony Patti <crypto(a)glassblower.info> wrote:
idk, when I type "TONY" into
https://boingboing.net/2025/03/10/make-your-own-virtual-punchcard.html
it does not match the output which I have at
https://www.glassblower.info/crypto/tony-punch-card.jpg
But maybe that's because, to find this punch card in my basement, in the
7th box which I looked in tonight,
that box was in the bottom of a locked filing cabinet, stuck in a disused
lavatory,
with a sign on the door saying "Beware of the Leopard" :)
My punch card is from Wharton's awesome KL-10 DECsystem-10, circa 1980,
contemporaneous photos here:
https://glassblower.info/Wharton-DECsystem-10/Wharton-DECsystem-10.html
Tony Patti
(ARPAnet NIC IDENT "TP4")
crypto(a)glassblower.info
-----Original Message-----
From: David C. Jenner <classiccmp(a)earthlink.net>
Sent: Monday, March 10, 2025 8:37 PM
To: Charles H Sauer (he/him) <sauer(a)technologists.com>; COFF <
coff(a)tuhs.org>
Subject: [COFF] Re: Make your own virtual punchcard
My first punch cards were in 1962, a first program for an IBM 709 Assembly
Language class. We used 026 card punches.
I wanted to emphasize a line in the comments region with an exclamation
mark. Not finding one on the 026, I did what we were taught in typing
class--type period, backspace, type apostrophe.
My first program was, of course, rejected by the card reader.
I think my box of program punch cards from many years of computing is
somewhere in storage in my garage. As well as a box of unused, original
cards from computing centers all over the country.^H'
Dave
On 3/10/25 2:45 PM, Charles H Sauer (he/him) wrote:
https://boingboing.net/2025/03/10/make-your-own-virtual-punchcard.html
[50 years ago today I started working at IBM Yorktown. My boxes of
punchcards from graduate work at UT-Austin were enroute with the
movers from Austin, to be fed into VM-370 after they arrived. I wish I
had kept those boxes as souvenirs.]
Charlie