Slashed letter O, unslashed letter zero

[Paul Koning]

> On Apr 27, 2022, at 1:22 AM, Chuck Guzis via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 4/26/22 20:10, ben via cctalk wrote:
>> On 2022-04-26 8:48 p.m., Chuck Guzis via cctalk wrote:
>> 
>>> CDC actually adopted OCR-A as their official internal font.  My office
>>> typewriter (Olivetti) had such a font.   I hated it.
>>> 
>> 
>> Well you can't have them use IBM equipment.
>> Looking at some IBM DOC's from the 60's
>> they had boxed tables for computer formats
>> but using real box characters.
>> 
>> +----+----+
>> | xxx| xxx|
>> +----+----+
>> 
>> How did they print that?
> 
> Cut and paste.  Consider the S/360 Assembler (F) manual:
> 
> http://bitsavers.org/pdf/ibm/360/asm/C26-3756-2_Assembler_F_Programmers_Guide_196711.pdf
> 
> Look at PDF page 10.   Note the box at the bottom of the page and how
> it's not even perfectly horizontal at the borders.  In fact, it looks to
> be hand-drawn.  I suspect that things were put together the old
> way--with scissors and rubber cement.

Or the way newspapers did it: with sticky wax applied to the back of the strips of phototypesetter output, along with rolls of "border tape" to lay down the straight lines.

Re OCR-B: the difference between zero and O in that font is small enough that contemporary OCR could not reliably tell the two apart.  This is documented in detail in "Travels in Computerland" by Ben R. Schneider, a book about his project to digitize a multi-volume printed document in the early 1970s.  It involved having it typed (in Hong Kong I think) using OCR-B type balls, and when they ran into the OCR issue it was worked around by modifying the type balls to give one of the two characters a cut in the left side, making it like a reversed C.  OCR sure has come a long way since then.

Yes, OCR-A is extremely ugly; Schneider actually considered it before dismissing it, on the grounds its letter forms are so bad that proofreaders trying to check the as-typed material would have a hard time dealing with it and quality would suffer as a result.

	paul