Fritz Chwolka wrote:
>
> Lawrence Walker wrote:
> >
> > 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_at_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.
> +-----------------------------------------------------+
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
--
-----------------------------------------------------------
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-
-----------------------------------------------------------
(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_at_gamewood.net
Sutherlin, Virginia 24594 Voice # (804) 799-5803
Received on Wed Feb 18 1998 - 12:59:06 GMT