[Coladam] CV Ultimate SD Cart on ADAM

Rich Drushel drushel at apk.net
Mon Jul 12 14:40:00 CEST 2010


On Sun, July 11, 2010 1:40 am, Steven Tucker wrote:

> So, I guess my questions are, can the CV cartridge ROM space be mapped into
> the ADAM space for programs to use the RAM, and if so would it be useful
> or would it displace any programs already running on the ADAM to do so?

     Hi Steve, I hope to be able to look over your technical info sometime
after work tonight.  However, I can say a few things off the top of my
head:

(1)  The cartridge ROM space can be switched in and out of the ADAM 64K
address space.  It occupies the upper 32K, which also is where the ADAM
EOS operating system code lives.  There is no way that I know of to make
the cartridge slot be the entire 64K of Z80 address space.

(2)  If your SD cart has some simple way to select RAM in banks (e.g.,
send a select value out some I/O port), then additional cart RAM could
be accessed, but again it would be in a 32K snapshot mapped to the upper
32K of Z80 address space.  Existing memory expanders (for right internal
slot) are accessed in this way.

(3)  Given (2), new ADAM programs could be written to take advantage of the
extra RAM, but existing programs would not be able to use it.

     All provisional of course until I can read your docs.

    *Dr. D.* (Rich Drushel)

-- 
Richard F. Drushel, Ph.D.            | "They fell:  for Heaven to them no hope
Department of Biology                |  imparts / Who hear not for the beating
Case Western Reserve University      |  of their hearts."
Cleveland, Ohio  44106-7080  U.S.A.  |         -- Edgar Allan Poe, "Al-Aaraaf"




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