Re: Apple ///?

[hirsch@ibm.net (Steven N. Hirsch)]

pubpc1@library.ucla.edu wrote:
: nathan@visi.com (Nathan Mates) wrote:
: >In article <5igjah$teu@uni.library.ucla.edu>,  <pubpc1@library.ucla.edu> wrote:
: >>How does the Apple III access more than 64K without bank
: >>switching?  It uses a mere 6502B with a 16 bit memory
: >>address.
: >
: >   It apparently doesn't switch full banks but lets you swap out
: >part(s?)  of main memory for some section of the extended memory.
: >Basically a far more intelligent, intuitive, easier to use, and
: >intelligent design than the 'bank switching' hacks of the //c and //e.

Yes.  Naturally you cannot switch the entire address range!  In
effect, that would be pulling the rug out from under yourself..
Although, now that I write that, I have seen this sort of trick work
in some very specialized cases.  But, I digress..

: >
: >   The Apple III had a bunch of far better designed sections than the
: >later //e and such, but Apple got the wrong idea into their head that
: >the III's failure was due to its extra features [and not stuff like
: >hardware more flakey than the day-old bin at a pastry shop, and making
: >life difficult for programmers and users who wanted to do Apple II
: >stuff], so they made the //e not that much more than the ][+.
: >
: >   If they'd put the good features of the III in the //e, without
: >sacrificing stability, things would have been much nicer. They were
: >already doing custom VLSIs for the MMU and the like, and it could
: >have been done.

Absolutely.  I recently laid my hands on a full set of SOS
documentation.  Nice design, well thought out.  Can't figure for the
life of me why they didn't merge some of the engineering work into the
IIe!

Steve