Re: TI-H: diskdrive 2 calc
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Re: TI-H: diskdrive 2 calc
>Implimenting the AT bus on a PIC is hard. You'll need to use one of the
>most
>expensive pics to get enough I/o. Or just use many latches and bus
>
>transcevers.
>-----------------------------------------------------
>Well,
>this is true except for one thing; I'm not using a floppydisk controller. I'm
>going to attach a pic directly to the diskdrive (this is why i said i haven't
>gotten all of the information yet, getting information about a controller
>would
>have been easy.) Because of the fact that a diskdrive only has 15 usable pins
>and i can loose 2 pins easily it can be possible (the problem is that i
>need 13
>lines for the diskdrive and 2 for the calc, but maybe i can lower this.)
>Well
>anyway, that's all.
>
>Neil
Most likely if you aren't using a controller you will probably need to time
things exactly on the dot or else it will fall apart. Like serial.
I could whip up an AVR that did it fine in 10 minutes. The problem with
the PIC is that it is literally 4 times slower than the AVR.
1 instruction cycle on an 8MHz AVR is 125ns. 1 instruction cycle on an
8MHz PIC is 500ns.
Just tell me and I could point you to some links about the AVR. They are
also cheeper. an 8515 with 32 I/O lines costs only $8. Power comes cheep.
I'll give some code on interfacing to the AT bus using the 8515 if people
wouldn't get over excited. :/
I think it would be just as fun to build on the PIC, but as far as sync, I
don't know if it can cut it. The instructions to read or set I/O port bits
could take up to 2us. Thats alot of time in the electronic world.
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