Any chance to reproduce an adjustment disk to set up drives ?

[Kris]

Hi all,


I have several drive which are very difficult to set up following a full disassembly. I know that an adjustement disk existed for amstrad repairer in the past but it seems that there is not any one of them saved nowadays...
If someone know how it was done (index position etc...) it could be helpful to fix those drives.


Any other suggestion is welcome of course

[Bryce]

The index is fixed on CPC drives, so no adjustment should be required. The only adjustments needed are speed - There's a very nice program to do this here: http://www.cpcwiki.eu/forum/applications/dsktest-v0-1b/   and alignment. I usually align drives by hand using a selection of original game disks, but even if you had dismantled the drive completely, you shouldn't have touched the alignment setting, there's no reason to disassemble this unless you needed to replace the head position motor.

Bryce.

[Kris]

Hi Bryce,

Thank you for your answer; Regarding drives i'm talking about, I had to change the head motor and that's the reason why I'm asking the question about the set up disk. I have already read something about that but I don't remenber where it was....and I can not open the "service manual" from the wiki.

[Bryce]

The service manual doesn't have any information on aligning the drive.

Have you tried reading an original disk with the DSKTest software?

Bryce.

[Kris]

I use to proceed like you describe to set up a drive: use several original disks to be sure that everything is working well.
Ex: I use discology 5.1 original disk to check drive then several original game disks to be sure of my set up; but in some cases, I have some troubles to load data correctly. In my last trial, I was able to launch discology 5.1, gryzor, gabrielle but the same drive is not able to launch Hercules II neither conspiration (disk tested OK on an other CPC). Those disks required a very tighted timing and I think my issue is coming from this "fine tuning".
@Bryce: Service manual joined, it may help you

[TFM]

Here optimized...

[Kris]

I come back in this thread as I would like to know if someone have some informations about the famous "EME CF2 test disk" which is listed in the DDI-1 manual ?
It seems that this disks is really helpful to perform alignment checks, set up, verifications etc... and I didn't find any details about its content.
Thank you.

[gerald]

I come back in this thread as I would like to know if someone have some informations about the famous "EME CF2 test disk" which is listed in the DDI-1 manual ?
It seems that this disks is really helpful to perform alignment checks, set up, verifications etc... and I didn't find any details about its content.
Thank you.

I've never seen one of these. But the DDI service manual has a good overview of what's on it.

On Track 19 : index bust + 2 burst + servo pattern
Index burst : used to align the index hole led assembly - You want a precise difference between the index and the burst.
2 burst : not used in the doc, but may be used to verify the head amp behaviour with 1F / 2F

On Track 39 : index + azimuth + servo pattern
Azimuth check : a pattern of 4 burst (probably recorder with different azimuth) that let you check that the head azimuth is correct. You cannot adjust this : if its wrong, change the head !
servo pattern : use to align the head with track, 47 blocks of 2 burst that are 90um around the track center. You need to make sure the amplitude difference is below a proper level to consider the track aligned.

Now, even if we put hand on a working calibration floppy, there is no way to duplicate it :
  - the drives have a fixed azimuth : no way to make the azimuth burst
  - servo burst need 2 different alignment.

[Kris]

You're right but I'm curious
With most of the informations we have in the manual, it is enough to fix a drive or to decide to change parts: I think I will be able to have a full working drive using 3 differents drives with different symptoms