> -----Original Message-----
> I have a recently new to me M200, and a couple M100s. The working M100s
> have 32K of RAM, while the M200 has 72K of RAM, in 3 banks of 24K each.
>
> I was surprised to learn that apparently the maximum amount of usable
> ram at one time on an M200 is under 20KB, even though is has more than
> twice the memory of the M100.
The keyword there is 'banks' - the T200 can have one, two, or three banks of
24k of RAM, and you can switch between them and copy files between them, but
you can't use them as contiguous space - only one bank can be mapped into that
address space at a time.
The deal is that they needed more ROM space for additional features of the T200
(Multiplan etc) and had to allocate 40k of the 64k address space to ROM,
leaving 24k for RAM.
> I guess maybe the REXCPM will have a contiguous 64K or RAM address space
> on an M200?
As far as Stephen has said, there are no plans for a T200 version of REXCPM.
That would only give you 64k of space in CP/M anyway.
> I'm mildly surprised that Tandy would have made an "upgrade" to the M100
> that even with more total memory could not run as large a program as the
> M100.
IIRC, the M100 was only sold in 8k and 24k versions, and to get 32k you had to
buy a 24k unit and an 8k upgrade module. (I don't think they ever sold an M100
pre-equipped with 32k but I could be wrong...) Since there were so many units
out there with 24k instead of 32k, that was the target for anybody writing a
large program - if you *needed* 32k to run a program you weren't going to have
many machines out there capable of doing so. I'm guessing this is why Tandy
felt most people would be OK with 24k in the T200, since that was the memory
size many programs were being targeted at.
I'm a little fuzzy on this, but I think they sold a 32k-equipped version of the
T102, but that came after the T200.
jim
