29 Jun
2007
29 Jun
'07
2:28 a.m.
Christian Corti wrote:
And don't forget the LGP-30 (450 built in total, 45 built in Germany)
and compatibles (LGP-21, ...). Its word size is officially 32 bits, with
only 31 bits usable (only the accumulator can hold all 32 bits, once
stored on the drum the LSB is forced to zero). So I call it a 31-1/2 bit
machine. And its design is marvelous, a CPU with all four basic
arithmetic functions (fixed point) that contains only 15 flip-flops.
Well, even the IBM machines had a full 32-bits per data word, but
addresses were 31-bits.
In any case, the LGP-30 (and LGP-21) were far (25+ years?) earlier than
the 370-XA machines. If memory serves, IBM didn't come out with 370-XA
until the early to mid '80s. But I wasn't kidding when I said they sold
thousands upon thousands.
Peace... Sridhar
Some other oddball values from that era:
- BINAC: 31 bits
I don't know if you can call 31-bit "oddball". IBM literally made
thousands upon thousands.