RE: C128D/1571 issue

 (Repling to myself as the wonderfull operator of my mail seems to eat most
(all?) replies to the ML from WebMail – previous mail was “sent” last
sunday)

 

So, I did some progress in the diagnose :

-          The 1571 electronic board is okay. I’ve tested it on a known good
C128D with good hardware and it operates well.

-          The head 1 of my “new” mechanic is okay (*)

o        Moved the head connector one step to the front

o        Defined 1541 mode “U0>M0”

o        Formatted successfully a disk (“unusable” as on wrong side and
reverse bit order)

-          Heads of my “new” mechanic seems to be correctly aligned as the
freshly formatted disk is readable on my regular C128D using 1541 mode
“U0>M0” and Head1 mode “U0>H1” (*)

-          Remains as possible issue head 0 by itself and the wiring of head
0 : Julian was right !

o        Compared impedances of both heads from yellow wire

*         Head 1 : Red = 20, White = 10, Blue = 20

*         Head 0 : Red = 0, White = 10, Blue = 20 

o        Seems that Red cable for head 0 is cut

 

(*) To test a 1571 with head 1 only, the trick of moving the head connector
is not needed, “U0>M0” + “U0>H1” are sufficient

 

==> Next question will be “Is there any way to reach head 0 soldiers without
messing everything” ?

 

Suggestions welcome – Regards - Hervé

 

 

 

  _____  

De : owner-cbm-hackers@musoftware.de
[mailto:owner-cbm-hackers@musoftware.de] De la part de hwarin
Envoyé : mardi 18 août 2015 01:17
À : cbm-hackers@musoftware.de
Objet : RE: C128D/1571 issue

 

Thanks, Wiliam, for instructions about disk alignment, that's instructive
and I've never risked myself on this until now...

My C128D is not a cost reduced one (it's a plastic case) and I never saw a
C128DCR sufficiently close to distinguish drive mechanics, I think it's
mecanically similar to "early" 1571 in your document.

Effectively, the drive might be misaligned as I have no history of it's
operation, but, even misaligned, it should be able to format a disk.

The idea of a trouble on head 0 is a possibility that I think to test at
first. My idea is the following.
- Move the head connector 1 step away (must check to confirm direction) in
order to have physical head 1 connected to electronic head 0
- Switch the drive to 1541 mode and try to format a disk

If it succeed, then I can go further on physical head 0 issue (or cable or
whatever). The drive should not be too disturbed by the head 1 being on air
in single head mode, whatever alignment is good or not; right ?

If it fails, then I may have either an head 0 (in electronic board) failure
or a mechanical failure.

To distinguish between a "drive" or "electronic" failure, I may also try to
swap electronic board with a known good one that I have right under the hand
- should have tried this at first time !

 

Will update you on my progresses - Hervé

 

 

  _____  

De : owner-cbm-hackers@musoftware.de
[mailto:owner-cbm-hackers@musoftware.de] De la part de william degnan
Envoyé : dimanche 16 août 2015 02:44
À : cbm-hackers@musoftware.de
Objet : Re: C128D/1571 issue

 

Try an alignment.  It is pretty easy to align the internal drive by
attaching an external drive and running the program found here:

http://vintagecomputer.net/browse_thread.cfm?id=519

Bill Degnan
twitter: billdeg
vintagecomputer.net

On Aug 15, 2015 8:32 PM, "Julian Perry" <jp@digitaltapestries.com> wrote:

With error21 (No sync)in most modes, my guess it's likely a failed R/W head
on side 0, or failed clamping/damaged head 1 spring.

Julian


 




Hi, friends

I recently bought a C128D in south of France during my holidays. It was time
for testings...

- The C128 by itself seems to operate perfectly correctly (that's it - no
deep test performed yet)
- The integrated 1571 can't read (write) anything. Here is what I've tried
so far

all 4 tests with any known good disk
1) load "$" => drive not ready (74) in 1541 or 1571 mode
2) switching to 1541 or 1571 mode result to read error (21) [18,0]
3) new command (n0:toto,xx) result to read error (21) [0,0] in 1541 mode
4) new command (n0:toto,xx) result to read error (20) [0,0] in 1571 mode

6526 resealted - heads cleaned
spinning and all 3 sensors seems okay

Does anyone have a suggestion for next steps ?

Regards - Hervé






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-- 
Best regards,
Julian                             <mailto:jp@digitaltapestries.com>
mailto:jp@digitaltapestries.com

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