C64-C128 CP-M Cartridge Interest
ard at p850ug1.demon.co.uk
Sat Dec 25 14:05:43 CST 2010
> > pair of 6303 microprocessors). But the 5.25" floppy drive appears to run
> > CP/M (or something close) on its intenral processor. The 3.5 drive, BTW,
> > doesn't...
> Ah HUH?
> Speaking for the PX-8 (I have three plus wedges and drives) the base PX8
> runs CP/M with a menu program on boot. If you escape from the menu it's
> stock CP/M. ti's clever for it's time in that the BIOS is complex and
> enough to handle a raft of storage devices be they based on R0M, RAM or
> a real floppy. As it turns out they made the floppy smart so that some of
Not forgettign the microcassette tape,. which is trated somewhat like a
slow floppy drive by the system.
> bios is in the floppy and the system can do directed calls to it so the main
> unit is relieved of some of the work.
> So the Floppy for the PX8 is specialized for a CP/M host it's not running
> CP/M itself as there is not enough ram alone to qualify.
Have you ever looked inside the TF20 daul 5.25" floppy unit? I beleive
schematics are on the web somewhere...
There is a heck of a lot of elkectronics inside. One large PCB containg a
Z80, 2K (IIRC) boot ROM ()with logic to switch it out after booting), 64K
DRAM, floppy controller, a duaghterboard with a 7201 serial chip, etc.
>From what others have been saying that's easily enough to run CP/M. Note,
I am not talking about the CP/.M that runs in the PX8 or wherever. I am
talking about the Z80 in the TF20 itself.
And the TF20 is not specialised for a CP/M host. The original application
was for the HX20, which as I said has a poair of 6303 CPUs and does not
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