I have seen this before, and I am not persuaded. I find it interesting 
that all of the references provided were written by Mr. Beemer himself, 
some of them with another author.

Perhaps, in hindsight it would have been better if IBM had made the 
System/360 an ASCII only machine. But at the time, ASCII was new and 
relatively unknown. As it was, the market had generally rejected ASCII 
on System/360, so the USASCII bit was removed with the introduction of 
System/370 in 1970.

Both ASCII and EBCDIC are limited. ASCII, even more so because it is a 
7 bit code, though there are proprietary 8 bit extensions. No one knew 
in 1964 that Unicode would later be designed based upon ASCII.

The claim that "A 1-to-1 translation between the two [ASCII and EBCDIC] 
exists" is false.Each includes characters that are not defined in the 
other. This has always been the case.

If IBM had "inflicted" ASCII on its customers in 1964, would the 
System/360 have had the wide acceptance that it did? We will never know.

According to "Architecture of System/360" 
https://cpb-us-w2.wpmucdn.com/sites.gatech.edu/dist/8/175/files/2015/08/IBM-360.pdf

<quote>
The reasons against such exclusive adoption was the
widespread use of the BCD code derived from and easily
translated to the IBM card code. To facilitate use of both
codes, the central processing units are designed with a
high degree of code independence, with generalized code
translation facilities, and with program-selectable BCD or
ASCII modes for code-dependent instructions. Neverthe-
less, a choice had to be made for the code-sensitive I/O
devices and for the programming support, and the solution
was to offer both codes, fully supported, as a user option.
Systems with either option will, of course, easily read or
write I/O media with the other code.
</quote>

Aside from that, it wasn't the "P-bit", but the A bit.

-- 
Tom Marchant

On Wed, 1 May 2024 11:31:56 -0500, Paul Gilmartin <[email protected]> wrote:

>Seriously!?  After IBM inflicted the burden of EBCDIC on users:
><https://web.archive.org/web/20180513204153/http://www.bobbemer.com/P-BIT.HTM>
>it chooses to torment them with the need to learn different conventions for
>various products?  Consistency would be a boon here.

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