6126 Plus and 3.5" drive problem.

[ComSoft6128]

Hi,
Bit of an irritating prob. My 6128 Plus arrived back repaired from Ian at Mutant Caterpillar. Drive A  now formats discs, loads games - everything working like new. Parados on cartridge or in a Rombox (with other Roms) also working. The final piece of kit to be added a 3.5" B drive just bought on Ebay from Greece. Now it gets really irritating - Drive A no longer works when Drive B is connected, in technical terms it is "a dead parrot". Panic! I remember the old horror stories when the Plus was a new machine - if Drive B is not wired correctly Drive A will rendered completely useless. So Drive B is removed and now Drive A is working again! Drive B has an ABBA switch and a side switch fitted onto the drive cable. I have set the switches to Drive B and side A but no joy. Does anyone have any ideas about this? I am thinking of having the switches removed but not sure if this will solve the prob.

[dragon]

You need to discard  things one by one, first you need try the fdd in onother cpc. Or another fdd in the cpc. That included the fdd wire.


Who are these guys of cartepillar,?. I read many times here about It.


And was  the original problem of the CPC?.

[rpalmer]

comsoft6128,

I would check if the 3.5 inch drive B works in a PC. If it fails you have a dead piece of kit.

I assume the external drive is unmodified.

rpalmer

[arnoldemu]

Who are these guys of cartepillar,?. I read many times here about It.

http://www.mutant-caterpillar.co.uk/

I believe run by one guy in the uk who makes quality repairs.

@Comsoft6128: Can you give a link to a similar drive on ebay from the same seller? If it's ikonsgr then I know it'll be quality.

Does the drive B have it's own power?
Is it "forced ready" with a connection?
What happens when you do CAT? does drive A do nothing?
What happens if you CAT drive B with a disc in drive A?

[tjohnson]

Hi,
Bit of an irritating prob. My 6128 Plus arrived back repaired from Ian at Mutant Caterpillar. Drive A  now formats discs, loads games - everything working like new. Parados on cartridge or in a Rombox (with other Roms) also working. The final piece of kit to be added a 3.5" B drive just bought on Ebay from Greece. Now it gets really irritating - Drive A no longer works when Drive B is connected, in technical terms it is "a dead parrot". Panic! I remember the old horror stories when the Plus was a new machine - if Drive B is not wired correctly Drive A will rendered completely useless. So Drive B is removed and now Drive A is working again! Drive B has an ABBA switch and a side switch fitted onto the drive cable. I have set the switches to Drive B and side A but no joy. Does anyone have any ideas about this? I am thinking of having the switches removed but not sure if this will solve the prob.

Have you tried the Greece drive completely in place of the plus drive?  Does it work when connected on its own?

[ComSoft6128]

Many thanks for the replies. In answer to your questions:
1. The original drive A failed in about 1999 due to the usual cause - stretching of    the drive belt. In the nearly two decades since then the drive belt had melted        into a messy blob.
2. Some Mutant Caterpillar repairs can be found on Youtube - the "Spectrum      Repair of Doom" is worth having a look at.
3. The 3.5 B drive works fine on both my 6128 Plus machines but only one of these has a functioning A drive - this is the Plus that just arrived back from being repaired.
4. The drive is from IKONSGR and I agree that it is a good piece of kit - in fact I have ordered another, this time without any switches on the drive cable. It takes its power from the monitor using a Y shaped cable.
5. With a disc in drive A and drive B connected - trying a CAT on drive A results in the standard message -"Disc missing, Retry Ignore Cancel". Drive B works fine CAT, LOAD and RUN still operate the usual way. Removing drive B then allows drive A to work again.
My previous experience of using a Plus is from 25 years ago when the drive B used an external PSU and that setup worked for many years. This drive was used for data storage - most of the discs were in Romdos D20 format with Parados on cartridge.

[arnoldemu]

I am sure I had this fault before.. I am trying to remember what it was....

[ComSoft6128]

I am hoping that the other 3.5 drive (minus switches) will resolve this. It was ordered last week so hopefully will arrive in the next few days. Will let you know the result. Cheers.....

[ComSoft6128]

The new 3.5 B drive and cable (minus switches) has arrived and been installed.
Everything works!
Drive A and B both function normally - I have copied files back and forth between the drives, formatted discs etc.
Why the switches would affect Drive A in this fashion I simply don't know but the end result is that after nearly two decades I have a fully functioning Plus.
Many thanks for all your help, it was appreciated.


Regards,


Peter

[Bryce]

These type of switches are a bodge. They permanently set signals that are shared between both drives, which means that the drives aren't able to set the signals to the state they should be.

Bryce.

[ComSoft6128]

Thanks Bryce


Interesting to know.


Cheers,


Peter

[The_Mole_UK]

The switches when wired right divide 80 tracks into 2x 40 tracks.  So therefore with AMSDOS you can format like a 3" drive.  You throw the switch for side B.  With something like ParaDOS installed, you can now format the full 80 tracks in one go, so therefore you do not need a switch.


If you hex edit $3FFE $03 to $33 in ParaDOS v1.2 then you'll have two 3.5" drives (great for WinAPE).  WinAPE sees the format, not the drive type, and a 3.5" and 3" drive can both format 40 tracks.   So you can use any format in any drive as WinAPE will see a 3.5" 40 as a 3" 40.  A 3" cannot read an 80 though, so $33 is better.


If you've hardware modded a CPC 6128 to use a 3.5" A (maybe your 3" is dead, dead) then again this tweak will benefit.  Otherwise use the standard $3FFE $03 and an ABBA switch for changing the 3.5" to A and 3" to B.  This is how I used to have it in the late 80s.  The side switch on the drive gives 40 and 40 instead of turning it over (for that mode you just need AMSDOS).   The ABBA is needed for games that won't run from Drive B.   Much more useful these days as everything is online and 3.5" 40 is the exact format of 3" 40.


Without a switch, AMSDOS cannot format from 40.  So you'll only get 178k.  With a switch you have 50% more of the disc available and 356k.