C64-C128 CP-M Cartridge Interest

[Tony Duell]

> > 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

Indeed...

> stock CP/M.  ti's clever for it's time in that the BIOS is complex and 
> complete
> 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 
run CP/M.

-tony