18 Feb
1998
18 Feb
'98
4:59 a.m.
Fritz Chwolka wrote:
Lawrence Walker wrote:
Hi Fritz:
The space between the head & pressure pad (single side drive. upper and
lower heads for ds drive), shold be on the order of 1/4" (6mm?) untill
the 'latch/loading lever' or other latching mechanism is engaged. At
which time the two pieces push together gripping the 'floppy' between
them.
The 'track 0' reset cycle happens _after_ the latching operation, as a
part of recognizing that the 'disk' has been changed. (Not just on
'power up').
Chuck
--
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He, who will not reason, is a bigot; William Drumond,
he, who cannot, is a fool; Scottish writer
and he, who dares not, is a slave. (1585-1649)
While he that does, is a free man! Joseph P. 1955-
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(be sure to correct the return address when using 'reply')
Chuck Davis / Sutherlin Industries FAX # (804) 799-0940
1973 Reeves Mill Road E-Mail -- cad(a)gamewood.net
Sutherlin, Virginia 24594 Voice # (804) 799-5803
I've searched the world web over ,but never did I find......
There seems to be a lot of info on Mods. 1,3,100,Coco etc. but nada
on this beast. Any sites I might have missed ? Merch , Cord ?
What I have is a TRS Model II with 1 internal 8' fdd and 1 external
fdd , 3 humungous 5Meg hdd ( about the size of a large XT) , K-B ,
TRS model 7 modem , and a box of 8" disks with CP/M 2.2 , TRSOS,
Scripsit and a bunch of other prgms.
When I boot up with or without an OS disk I get a "boot error ht'
msg. The dd spins up and sounds like its loading. Could it have been
set up to boot off one of the hard drives ? I'm really a novice with
TRS-80s but have Coco 1 and 2 in my collection and a Scriptsit cart.
Is there something I'm not doing ?
ciao larry
lwalkerN0spaM(a)interlog.com
Great... that you got such a fine part.
I've a TRS80 MII too but without a harddiskdrive.
For other use I add an extern DSDD 8" diskdrive.
The internal diskdrive is singlesided I believe it's a shugart 801.
I got several errormessages during bootup every time I tried to do
so which was every 2-4 months.
My problem was the dispositioned head of the diskdrive.
(1) --------------------\
---------------+ !
!----!
(2) +-----+__ 1_2_3_____...77+----------
!_____+------------------+__________
(3) -------------- /====\
There I trie to show the disk with head and the part against the head
for the singlesided drive.
If you put in the disk between part (1) and (3) must be place enough to
insert
the fleydisk into the drive. If there isn't enough place the disk will
become
contact with part (1) or (2) and you throw the head backwards. If you
don't recocnise it and after some triese are able to get the fleyxdisk
into
the drive you change the correct position of the head against track
zero.
Normaly the head must find track oneduring bootup. If the system boots
the diskdrive will reset the position of the head(s) and a indicator
says
now the head is in Track 0 position. The the stepper stepps backwards
from track
to track.
Dispositioned head:
(1) --------------------\
---------------+ !
!----!
(2) +-----+__ 1_2_3_____...77+----------
!_____+------------------+__________
(3) -------------- /====\
Here you see that the head can't stepp backwards during the poweron /
reset time
because during inserting the flexydisk I dispositioned the head.
The distance between (1) and (3) was to small because part (1) fall down
from
the metallplate which make the headload.
Now during boot I got a DC error.
It's a nice mechanical problem in my case and maybe you have the same.
Even the indicator for Track 0 maybee dusty or inoperable.
Greetings
Fritz Chwolka / collecting old computers just for fun.
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