28 Jan
2009
28 Jan
'09
12:33 a.m.
Tony Duell wrote:
IIRc, the Model 3 can physically read any M1 disk,
although it can't
necessarily write them (The M1 used one of the 1771's 'extra' data markers
on the directory cylinder, which later disk cotnrollers couldn't write).
I cn't rememebr about OS compatibility -- LDOS, which is what I mostly
use can read M1 TRS-DOS or LDOS disks on a model 3, but I have an idea
TRS-DOS won't. And binary programs generally won't run on the other
machine -- almost all the OS routines changed their addresses :-(
The Model III versions of LDOS, DOSPLUS, MULTIDOS, and NEWDOS/80 could
all read Model I TRSDOS disks. Model III TRSDOS 1.3 couldn't read them
directly, but it did come with a conversion utility.
Most programs written after the introduction of the Model III worked on
both computers. There were some programs with separate versions, but
they tended to be low-level utilities or self-booting games. Programs
written before the Model III was introduced were another story.
--
Matthew Reed
http://www.trs-80.org
mkr at trs-80.org