> -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Clark Kidd > Sent: Thursday, May 28, 2009 12:35 PM > To: [email protected] > Subject: Punched Card Combinations (WAS Book on Poughkeepsie) > > It was not all that difficult to look at the holes on a punched card > and figure out what each column represented. > > If you have an older "System/360-370 Reference Summary Card" (the old > green or yellow multi-folded cards), there was a section called CODE > TRANSLATION TABLE, and a column titled "EBCDIC Card Code" that contains > the card columns that would be punched out to generate the specific > values from X'00" to X'FF'. My handy yellow card is dated March, 1974 > and it contains this column. For example, the letter "A" or X'C1' > could be represented with a 12-1 punch. > > As I remember, there were three "control" rows at the top of the card > (12, 11, 0) and then 9 "data" rows (1-9) under those. So each possible > column would contain up to 12 rows that could be punched:
Which is at least part of why the sequence 'A'....'Z' is disjoint in EBCDIC. Dave Gibney Information Technology Services Washington State University ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
