Re: LZ: Extended mem. format
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list-zshell@lists.ticalc.org wrote:
>
> Most likely you can store all stuff on the extended memory, but to use
> it on the calc you will first have to laod it into the calc's normal
> memory -- so you have 28k free
> something that will access this external mem and zshell type thing
> will take up lets say 5k
> so now we have the largest stuff at 23k
>
> not bad when you are talking the gameboy games were origionally 32k
>
> so here the dela we need in this zshell type program a make var
> rountie or somethin like this
>
> or you could have a gam lets say like Super Mario Bro... at first it
> load the first board into clacs "normal mem"-- then when you are done
> the first boadrd then the 2nd and so on, but this may not work--
> cause in SMB, you will need routines to find stuff in the exteranl
> mem--
>
> soultion****
>
> 1.on the calc-- you have in the zshell type prgram rounties to make
> and delete vars in the noraml mem
> 2.and in that program you have routines to access any section of of
> the external mem...
>
> so in conclusion, you can load level 1 into the calc-- then once you
> beat it level 2 is loaded on etc...
>
> tell me what you think of this!!
> Eric Linenberg
> elinenbe@umich.edu
>
> for information on EVERYBODY from High School go to
> http://www.umich.edu/~elinenbe/
>
> im that kid in the corner all fucked up and i wanna
> so im gonna take a piece of the pie why not im not
> quittin think im gonna change up my style just to=20
> fit in
No. Here are two practical solutions to extra memory for the calc...
Passive. We interface a microwire eeprom (its three wires, clock, data
in, and data out. I believe its possible to combine the data in and data
out using passive components, but well have to look into that). I Have a
500k-byte EEPROM with a microwire interface, if that isnt enough, they
have a 1-meg one you can buy. Basically we wire this to the link port,
and do the rest in software.
Active. I like this one better, because you could add a lot more to it.
Basically, you take another microprocessor (Probably a Z80, since we
already know how to program it) We could hook it up so that if your calc
got reset, you could program the thingy to automatically send a backup
to the calc if you did an input "cblget",blah or whatever on a cbl calc
and go to link receive or whatever. This way there could be variable
send/raw send/etc. The only problem is that i doubt if anyone has had
any experience working with microprocessors and stuff (Me Included, i
got the idea from my Z80 book). Wed at least need a microprocessor, rom
code, actually, would probably be eeprom that would be locked by a
special switch so that updates could be done without needing a burner.
Wed also need either static ram or eeprom, or both maybe. We could leave
the scematics open-ended (same with the rom code) so that if someone
wanted to use eeprom for no-power storage, and static ram for fast
access, although it would be through the link port, so it would be
pretty slow. Anyway, i think the practically of this is limited by the
fact that it would be to big and bulky.
Steve
p.s. To anyone that knows the ram+rom of the ti-85, is any of it unused,
i wonder how hard it would be to tap the bus (wed only need maybe 16k of
address space plus a free port or two for a page switcher. The problem
would be fitting all the crap in the case. oh well.
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