2 May
2005
2 May
'05
8:04 a.m.
There was one at Harvey Mudd College -- it was hated
by the programmers
there as well. If I remember correctly, it was 8086-like in that it
was a 16 bit architecture extended to address more memory, probably
via segments. I do remember that arrays were limited to 64K.
Yes, 50-series machines had segmented architecture. Most code since
1980 or earlier ran in 64k segments. IIRC, 64R-mode code was limited
to one segment; 64V-mode code could span many. Older addressing modes
were limited to 16- or 32-k. In theory, the compilers would allow
data structures to cross segment boundaries, but in practice, they
often had bugs that prevented such behavior from working correctly.
I was bitten several times by large array issues.
Since it was all virtual, the usual mapping had user code in segments
4000-4???; stack was in segments 6000 and up. The OS lived in (some
of) the first thousand (octal) segments. Seems like the shared code
segment bits of various products (compilers, MIDASPLUS, etc.) lived
in the 2000 range.
De