28 Feb
2010
28 Feb
'10
12:24 p.m.
I checked with a friend whose memory is better than mine.
A TRS-80 Model I can duplicate bootable Model III diskettes. The Model III disk controller
cannot produce all the address marks the WDC 1771 can, so a Model III cannot duplicate a
Model I diskette if the OS or bootcode is dependent on having those address marks
present.
So, anyone with a Model I who has good copies of Model III OS disks should be able to help
the poster.
I'd make several copies of each just to control for the age of the media and different
drive alignment. Do one drive 0 to 1 and the other drive 1 to 0.
My system isn't setup yet, else I'd volunteer. Hopefully, I'll have it setup
in a couple of weeks.
Al
28 Feb
28 Feb
1:37 p.m.
I checked with a friend whose memory is better than mine.
A TRS-80 Model I can duplicate bootable Model III diskettes. The Model
Only if the M1 has a double-density board fitted. The M1, by default, has
a 1771 controller chip which can do single-density only. Model 3 disks
are normally double-density, in fact I think the boot sector has to be DD
for the ROM bootstrap to load it.
III disk controller cannot produce all the address
marks the WDC 1771
can, so a Model III cannot duplicate a Model I diskette if the OS or
bootcode is dependent on having those address marks present.
True.
-tony
3:22 p.m.
On Sun, 28 Feb 2010, Al Hartman wrote:
I checked with a friend whose memory is better than
mine.
Your memory may be better than you think. You just need to refresh the
RAM
A TRS-80 Model I can duplicate bootable Model III
diskettes.
NO. The stock controller of a Model 1 is a single density 1771. The
default density of Model 3 formats is DOUBLE (MFM).
A model 1 can be MODIFIED (with Percom Dobler or later copies thereof) to
be able to do MFM. The stock Model 1 can not.
A model 3 CAN boot from single density, so it is POSSIBLE to create a
non-standard Model 3 boot disk that can be duplicaated by a model 1.
The Model
III disk controller cannot produce all the address marks the WDC 1771
can, so a Model III cannot duplicate a Model I diskette if the OS or
bootcode is dependent on having those address marks present.
correct
So, anyone with a Model I who has good copies of Model
III OS disks
should be able to help the poster.
My model 1's, which are now in Eric Smith's ownership, possession, and
storage, had sandwich boards in the FDC to be able to handle 8" disks.
At the time that I parted with them, they did NOT have Percom Doublers,
and could NOT duplicate model 3 disks.
For reasons that I'm not sure of, stacking multiple sandwich boards (8",
data separator, doubler, etc.) did not work reliably.
Model 3 disks can be duplicated with a Model 3 or 4, or with a Kaypro, or
with a Morrow, etc. Or, with a Model 1 PLUS a Percom Doubler.
They can be written, created using a 765 in a PC, but there may be
complications reading the originals. (Try masking off the index when
reading them in a PC)
--
Grumpy Ol' Fred cisin at xenosoft.com
5415
days inactive
5415
days old
2 comments
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participants (3)
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alhartman＠yahoo.com -
ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com