The ones I know are:
(precision is single/double)
GE 600 (later Honeywell 6000) were 36/72 bits ascii based character
set, either 6/6 bit or 4/9 bit per word. (Multics PL/1 allowed direct
access to EIS (Extended Instruction Set, not used by GCOS)unit which
sup****ted 63 decimal digit maximum precision)
DEC PDP -10/20 was 36/72 bit. ascii characters were 5/7 bit per word
Amdahl was an IBM 360/370 clone with the same instruction set 32/64 hex
based, EBCDIC characters 4/8 bit/word. I think there was some sup****t
for 128 bit floating point, but it was not part of the original 360
instruction set.
CDC and Cray(?) were 60 bit, no hardware double IIRC. There were also 4
special flag bits to indicate that the value was the result of things
like division by zero, underflow, overflow (again IIRC). 10/6 bit per
word.
I don't really know what the rest were, but I think many were either 36
bit or machines deisgned after 360 may have been 32 bit to be more
compatable with IBM.
John W. Kennedy wrote:
> hancock4@[EMAIL PROTECTED]
wrote:
>
>> John W. Kennedy wrote:
>>
>>> It is very well known that the entire 360 FP feature could have used
>>> some input from numerical analysts; it's shot full of design defects.
>>
>>
>> Could you elaborate on those design defects?
>>
>> How did S/360 compare with its predecessor machines (ie 709x) regarding
>> those defects? What differences did competitors machines--those
>> available in 1965--have compared to S/360 regarding these defects?
>
>
> To start with, the S/360 word was four bits shorter than the 704 word.
> This was, at least, a strategic error, because it meant that /up/grading
> to a 360 meant, in this area, a /down/grading in function.
>
> But the hexadecimal base further meant that the effective length of the
> fraction was essentially 21 bits (single precision) or 53 bits (double
> precision), rather than the superficial 24 or 56, and this was not
> clearly understood at first.
>
> Other problems were corrected in a massive Engineering Change, which
> added a guard digit to double precision, added postnormalization to the
> halve instructions HER and HDR, and changed the results returned in
> cases of overflow and underflow.
>
> The early competitors generally had words longer than 32 bits, but I am
> not familiar with any of them in detail.
>
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