Re: AE memory for //c

[ddkilzer@iastate.edu (David D Kilzer)]

robert-s@cs.aukuni.ac.nz (Robert Sheehan ) writes:

>Can anyone tell me why my AE ZRam II with 1 MB only lets me use 15 of the
>16 64K banks of memory.  I don't think it is broken, they just made them
>this way.  It is the //c equivalent of an aux mem board.  You change banks
>by hitting $C073, bank zero is normal aux memory.

>I've got this horrible feeling the answer is to do with the number of
>bits they used for bank selection (16 needs 5 bits).  In which case they
>should not have advertised it as a 1 Meg board since you can only use
>960 Kbytes.

That sounds right.  I remember reading in the manual that the memory
card "made" the //c have over 1 Meg of memory...if you add in the 128K
that's already there.  Bad advertising, no?

>Whilst on the topic there is a lovely bit of code in the manual which tells
>you how much aux memory you have available, with a couple of seemingly
>worthless lines.  It took me a moment to work out that these lines are
>there to make other aux memory boards fail (I used to have a Checkmate
>board).  I thought that was pretty mean as some software developers used
>the code without thinking thereby making their software only work with
>AE hardware.  I don't know which was worse, the dumb software writers or
>AE for trying to zap the opposition.

Hehehe.  That's interesting.  Not that you could fit something else
besides a Z-RAM Ultra II (except maybe a Zip Chip, but you have to
remove the original 65C02 ;^).

>OK, I suppose they were the first to develop aux mem boards but still.;)

Dave
-- 
David D. Kilzer               \                ST:TNG _Relics_
Computer Engineer 3           /       Capt. Montgomery Scott ("Scotty")
ddkilzer@iastate.edu          \   "I may be a captain by rank, but I never
Iowa State University, Ames   /    wanted to be anything but an engineer."