Re: Jensen's device

scott@basis.com (Scott Amspoker) wrote:


[snip]


>Speaking of language "mistakes": I had the misfortune of taking a class in
>PL/I back in the 70's. That was still a time of punched cards. PL/I
>statements (on an IBM machine) had to start in column 2 or greater. This
>seemed perplexing at first. What was so damn special about column 1 that we
>couldn't touch it. A classmate made the connection and pointed out that the
>problem was the open-comment delimiter: '/*'. Those with past experience
>with IBM JCL (or OCL for you System/3 fans) will remember that a punched card
>containing '/*' in column 1 was and end-of-file marker.
>
>I often wondered if PL/I design commitee realized the conflict late in the
>project and decided it would be easier to insist that PL/I statements not
>start in column 1.


          While the above may well be so, it is also true that often the
first character of a line sent to the printer was for printer control.
"1" for page skip, " " for single space, etc. There were characters
for doublespace ("0"?) and overprinting ("+"?), and triplespacing
"2"?). I think you may have been able to use these in PL/I code to
pretty print.


Sincerely,


Gene Wirchenko
[Indeed you could. It's all coming back to me now. Yuck. -John]
--

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