10 Apr
2024
10 Apr
'24
7:25 a.m.
On 4/9/24 23:51, Van Snyder via cctalk wrote:
I don't remember whether it was one of the docents
at Haus zur
Geschichte der IBM Datenverarbeitung at Sindelfingen, or at the
Computer History Museum at Mountain View, who told me that IBM was
developing a machine to be designated 1480, as part of the 1401-1440-
1460-1410 series, with newer technology, roughly contemporaneously with
the 360. When IBM decided to put all its eggs in the 360 basket, The
1480 team somehow survived and produced either the 360/20 or 360/25. An
8k machine would be a bit weird in this series, since 1410 was already
100k. Does anybody know more details about this?
The model 20 could have between 4K-16KB memory initially; later it was
expanded to a maximum of 32K.
The model 30 was configured with a minimum of 8KB up to 64KB. I'm not
sure if DOS/360 could run in 8KB; I don't know how common 8KB model 30s
were, but I've never seen one.
The big difference is that the model 20 is really a 16-bit machine, with
16-bit general registers and a very pruned-down instruction set with a
considerable number of differences from the bigger systems.
--Chuck