16 Dec
2018
16 Dec
'18
8:39 p.m.
> However, the PX-8 3.5" had 40 cylinders,
with 67.5 tpi, instead of the
> common 80 cylinder 135 tpi of other 3.5" disks.
> Those 40 cylinder 3.5" drives are quite rare.
Somewhere in my searches I
recall reading that the 3 1/2" drives used the same format as the 5 1/4" ones.
Maybe 40 tracks of 16 256 byte sectors. Oddly, I believe that 2 tracks are "reserved
for CP/M" even though it is in ROM and not stored on disk.
ceramic magnet lost its stuff over time.? When I have
time the next
project will be a Atmega2650 running
a CF to via serial interface.? The drive table can be patched for a
larger (up to 8mb) drive.
I've been planning something very similar for a
while, but using an Arduino (ATMega 328) or bare AVR chip and probably a smaller/simpler
flash chip. I din't know about the drive table. That's interesting. Would a new
ROM have to be burned with the new table? Do you have an links to the info?
With appropriate format handling software on the PC, it should be
possible for a PC connected using your system to work with actual
Epson diskettes, and emulate the Epson external drives.
There are several software packages on the net to do the fake of the
disk via serial and manuals of the system to
explain the format.? Likely that software could do the earlier HX20 (and
friends) with minor tweaks.