A85: Re: Compactflash expander
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A85: Re: Compactflash expander
Only one thing to add: how about support for all TI-8x calcs? I mean, it
couldn't be very difficult to port the code, as all have a Z80 on them...
On that note, I would also like to suggest that Usgard possibly be ported to
run on the 86, etc... it would make the 86 a much more friendly asm
device...
..Trevor
PS - I am going to devote some time this spring break (from right now until
a week from monday) to actually learning how to program for Usgard (I know a
few different flavors of assembly, but not Z80)
If anybody would care to send me some sample programs, etc, I would GREATLY
appreciate it!
----- Original Message -----
>The past couple of weeks I've been thinking about making a memory
>expander for the 85. However, unlike the previous expanders built, this
>one would use Compactflash cards as the storage device, instead of built
>in memory chips.
>
>I thought of using Compactflash cards mainly for expandability reasons.
>Its true that all the programs ever made for the 85 probably wouldn't
>take up more than a meg or two, but that is bound to change. Using the
>flash card approach, the user can choose how much storage he/she needs,
>and purchase the appropriate card. And unlike the presend expanders, if
>you run out of room, you don't have to delete items off the expander,
>you merely slide in another card.
>
>The point of an expander, in my view, is not only to give you extra
>storage, but to expand the entire capability of a device. Now I've never
>pretended that I was down with all the ideas floating around this list
>about adding MIDI, Firewire, peripheral support, and things like that to
>the calc. To me it always seemed like beating a dead horse. But just for
>the sake of tinkering, I thought I'd give it a try.
>
>If I ever get this done, the expander will probably have:
>
>1 Compactflash type I port (for type I cards)
>1 Compactflash type II port (for type II cards & IBM's Microdrive)
>1 to 2 USB ports (for anything else people want to add)
>1 standard TI link port
>
>
>The shell running on the calc will need built in support for the
>expander, hopefully that would be a future version of Usgard, but who
>knows. The point is that the shell must be able to read and manipulate
>the files on the expander. And unlike the expanders we have now, you
>won't have to copy items from to the calc, the shell will take care of
>that. When you run the shell, it will list all the files on the
>expander, whether they be programs or documents. When you run a program,
>the shell copies as much of the program as it can, into the 85's memory,
>copying the rest into virtual memory on the expander. And when the
>program stops running, the shell copies the program back to the
>expander, overwriting the old prog. Then the shell deletes the prog from
>the 85's memory. Its just a modified version of relocation, but it
>functions more like a regular computer. The shell would probably do this
>using a variable table. When the shell is started, it scans the 85's
>memory for variables and stores them in a table. After executing a
>program, it rescans the memory and checks for new vars. When it finds
>them, it deletes them. This way, it protects any variables you already
>have in the calc.
>
>The expander will also have its own link port, so you can transfer files
>directly to the expander, instead of having to use the calc as a
>go-between.
>
>There are a lot of USB products out these days, so I'm sure those ports
>will come in handy. If you wanted you could plug a USB hub into a port,
>and hook up a keyboard, a mouse, a modem, and a set of USB speakers and
>still have room for 123 more devices. I figure it'll take you guys a
>while to fill that up.
>
>At present, Compactflash cards operate in 3 modes: memory card, I/O
>card, and IDE mode. For the sake of simplicity I'll probably have the
>cards run in IDE mode. That way, it will interface just like a hard disk
>drive. And it will probably be formatted in UDF (Universal Disk Format)
>so it will be cross-platform. If you have a pc-card drive, you can just
>flash the card with all your files and won't have to waste time with the
>link.
>
>Just so you'll know, I'm making this more for myself than anything, but
>I thought I'd throw it out there just to see what you guys thought of
>it. It's in purely experimental stages right now, focusing mainly on the
>hardware aspects. I'm trying to get all the info I on controller chips
>and such so I can figure out how to wire this sucker. In short, I can
>use all the help I can get.
>
>
>Sincerely,
>Jason Blakeley
>
>Confucius say:
>"He who stand on toilet, is high on pot!"
>
>
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