1 Dec
1999
1 Dec
'99
11:21 a.m.
"Dave Baggett" <dmb(a)itasoftware.com> wrote:
Tony Duell wrote:
Hi
I would still suspect it might be in the machines. As was mentioned,
the HDOS and CPM memory models were different. If the modification
wasn't done correctly, it may be that both machines will only
boot CPM and are not able to boot HDOS without undoing the mods.
To convince your self, why not look at the read data signals
on coming from the disk. I would think that a weak signal
would show as a lack of transitions on the read data.
Dwight
As regards getting more hard sectored disks,
I've not found a source.
Actually, I found a place on the web today (about 10 miles from my
house, amusingly) that can make 10-track hard sector floppies. They
say it will take 3-4 weeks, but were willing to sell me some for $1 a
piece, or cheaper for quantities of 5000 or more. :)
Here's their web address: http://www.athana.com
On the subject of the nonbooting HDOS disks, I don't think there's
anything wrong with the machine (I have two separate machines
exhibiting the same behavior, after all) -- I think the disks are just very
borderline. I adjusted the rotational speed on one of the H89's
(it should be 200 according to my Heath manual) and then was able
to get one of the HDOS disks to almost boot. But part way through the
boot sequence it gets some unpleasant error and complains. So I
suspect that if I had a fresh copy of an HDOS disk it would boot.
Still don't know why the CP/M disks fared better, but perhaps they're
a bit younger...
Dave