If "S" was assigned the 0 and 2 rows because 0 and 1 were too close together, 
then
why was "/" given rows 0 and 1? Does that punch a hole in this theory? GD&R

Bill

On Tue, 2 Jun 2020 14:30:52 -0700, Charles Mills wrote:

>"Laced" (every hold punched) cards were an amusing bulletin board item.
>
>And yes, I believe I heard at the time @Jesse's premise as to why 'S' did not 
>use row 1.
>
>Actually, the alpha codes are as follow:
>
>A - I, row 12 plus rows 1 - 9
>J - R, row 11 plus rows 1 - 9
>S - Z, row 0 plus rows 2 - 9
>
>So you see that if S used row 1 it would have had two adjacent rows punched, 0 
>and 1.
>
>(The rows, from top to bottom, are 12, 11, 0 - 9.)
>
>Non-alphanumeric punches were fairly rare, and column binary was extremely 
>rare.
>
>Object code decks of course contained non-alphanumeric punches. The X'02' that 
>begins each (traditional) object code record, preceding ESD, TXT, RLD or END? 
>I still think of it as "12-2-9.")
>
>Charles
>
>
>-----Original Message-----
>From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On 
>Behalf Of Steve Smith
>Sent: Tuesday, June 2, 2020 2:07 PM
>To: IBM-MAIN@LISTSERV.UA.EDU
>Subject: Re: Punched cards and character set
>
>That's plausible, I think.  While there are plenty of adjacent punches in
>the full 256-characters, I'm sure most cards were mostly alphanumeric only,
>and it might pay to make them as strong as possible.  I remember seeing
>some cards that were punched in every position; those were very delicate,
>and definitely couldn't survive a pass through a card reader, regardless of
>the fact they had no validity at all.
>
>sas
>
>On Tue, Jun 2, 2020 at 4:55 PM Jesse 1 Robinson
>wrote:
>
>> I haven't seen this mentioned. The punch card codes for letters went like
>> this:
>>
>> A - I rows 1 - 9
>> J - R rows 1 - 9
>> S - Z rows 2 - 9
>>
>> So why was S assigned to row 2 instead of row 1? The answer I was taught
>> was that row 1 was  too close to an adjacent location. The punching/reading
>> devices and card stock of the day could not reliably handle punches that
>> close together, so row 1 was skipped for the third alphabetic sequence.
>>
>> What's amusing is that this pattern was carried over to EBCDIC. The code
>> for S likewise skips a possible combination: D9 to E2; 'E1' is not assigned
>> to an alphabetic character.
>>
>>
>

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