On Fri, 19 Feb 2016 22:08:44 +0000, Gibney, David Allen,Jr wrote:

>> -----Original Message----- 
>> From: IBM Mainframe Discussion List [mailto:[email protected]] 
?> On Behalf Of Paul Gilmartin 
>> Sent: Friday, February 19, 2016 2:02 PM 
>>
>> EBCDIC is a pain.  It should have been ASCII.  Or IBM should finish 
>> implementation of Enhanced ASCII support.
> 
>Can you really imagine the level of acceptance (NOT) that would have received 
>2.5 decades ago :)

MVS OpenEdition, as it was called in MVS/SP 4.3, wasn't especially well 
received 
when it was announced almost 2.5 decades ago. Would it have been better 
received 
if it had been ASCII?

ASCII was seriously considered for the initial System/360 design. Amdahl, 
Blaauw and 
Brooks published an article in the IBM Journal in April, 1964, titled 
"Architecture of the 
System/360" in which many of the design trade-offs were described. One place 
where 
the article can be found is 
http://web.ece.ucdavis.edu/~vojin/CLASSES/EEC272/S2005/Papers/IBM360-Amdahl_april64.pdf
 .

<quote>
ASCII vs BCD codes. The selection of the 8-bit character size in 1961 proved 
wise by 
1963, when the American Standards Association adopted a 7-bit standard 
character 
code for  information interchange  (ASCII). This  7-bit code is now  under  
final  
consideration by the International Standards Organization for adoption as an 
international 
standards recommendation. The question became “Why not  adopt ASCII as  the 
only 
internal code  for System/360?’

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. Nevertheless, a choice had to be made for the 
code-sensitive 
I/O devices and for programming support, and the solution was to offer both 
codes, as a 
user option. Systems with either option will, of course, easily read or write 
I/O media with the 
other code.
</quote>

-- 
Tom Marchant

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