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General Category => Technical support - Hardware related => Topic started by: Jonathan on 23:01, 17 May 25

Title: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Jonathan on 23:01, 17 May 25
I asked a question in the software category about getting drive A: software to work on a Gotek and, understandably, mainly got hardware recommendations: https://www.cpcwiki.eu/forum/software-related/how-to-run-drive-a-required-software-from-a-gotek-drive-b/

At that stage I thought I needed advice, but really what I need is to post the Gotek to someone and pay for a switch to be added! 

Quote from: Jonathan on 18:58, 03 April 25Some of the ribbon is inside that case. Ideally I think I'd like to put a switch on that "hidden" part of the ribbon and connect it to a switch on the outside of the case.

Second best would be to put one of those little switches across the ribbon, just behind the outer case.

Who would be willing to do that?

(There is a cable on eBay with a switch - the seller is "urban-retro" - but I don't even trust myself to remove the cable from the back of the Gotek, as it has lots of wires cable tied together and can't be removed fully from the case.)

Thanks in advance.
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: St-BeidE(DE/GB) on 10:08, 18 May 25
What Country are you from?
I guess it is too expensive to send it across
two borders - and even more expensive, 
across the ocean.

Stefan 
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Jonathan on 10:38, 18 May 25
The United Kingdom. Though if nobody local can do it I either take the risk on doing it myself, or look into international postage! Thanks. 
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: eto on 13:52, 18 May 25
Quote from: Jonathan on 23:01, 17 May 25it has lots of wires cable tied together and can't be removed fully from the case.
That sounds a bit strange. Can you take a picture of the cable and the Gotek?
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Jonathan on 15:55, 18 May 25
There's one in post #20 of the other thread. "Lots of" is from my perspective. From yours it might not be daunting at all.
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Rabs on 19:54, 18 May 25
Quote from: Jonathan on 10:38, 18 May 25The United Kingdom. Though if nobody local can do it I either take the risk on doing it myself, or look into international postage! Thanks.
Where are you based in the UK? I am in Hampshire. So you just want a 34 way header crimping to the ribbon cable and a jumper/switch for pins 11-12? 
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Jonathan on 10:56, 19 May 25
Yes, that's exactly it, thank you. I'll send you a PM now.
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Jonathan on 16:11, 19 June 25
@Rabs created this switch. It arrived today and works perfectly! I am very grateful indeed.

It goes between the CPC and the Gotek ribbon - see photo.

You turn on the CPC, then switch to "B->A" mode, and the external Gotek becomes drive A:

Then "drive A: only" software can be run straight from the Gotek.

When you turn off the CPC, just switch it back to "A->A" mode. Surprisingly, it seems to work when kept permanently on "B->A" mode - but that keeps on the Gotek power light so I guess it might be wiser to switch back to "A->A" before powering off the monitor.

Obviously the CPC will recognise only one drive at a time, so it's an "AB" switch as opposed to the well-known classic "ABBA" switch. That's fine by me as I never had a second drive in the 80s.

Rabs will put it on Github so that anyone can build it.
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: SerErris on 18:46, 22 June 25
A ABBA switch would require soldering and trace cutting inside the 6128, as it was never meant to need that functionality.
In the old days there were only 3" inch drives (from Amstrad) and therefore it did not matter that the internal drive would be always drive A (hard wired) and the external drive will always be Drive B (also hard wired).

This is the ABBA switch required. This is a cutting and soldering job. However it is a permanent change to a 6128, you need an additional switch (2P2T) and you need to drill a hole in the case to mount the switch (not to have it dangling). 
https://www.cpcwiki.eu/imgs/c/c8/ABBA_switch.jpg
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Jonathan on 19:00, 22 June 25
Yes that's the famous ABBA switch, but I didn't want any surgery done on my old 6128 :-)
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Rabs on 21:47, 22 June 25
I have posted the Drive AB Switch details to GitHub, which can be found here Amstrad CPC Drive AB Switch (https://github.com/rabs664/Amstrad-CPC-Drive-AB-Switch).
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Solo Kazuki on 07:07, 23 June 25
Quote from: Jonathan on 16:11, 19 June 25@Rabs created this switch. It arrived today and works perfectly! I am very grateful indeed.

It goes between the CPC and the Gotek ribbon - see photo.

You turn on the CPC, then switch to "B->A" mode, and the external Gotek becomes drive A:

Then "drive A: only" software can be run straight from the Gotek.

When you turn off the CPC, just switch it back to "A->A" mode. Surprisingly, it seems to work when kept permanently on "B->A" mode - but that keeps on the Gotek power light so I guess it might be wiser to switch back to "A->A" before powering off the monitor.

Obviously the CPC will recognise only one drive at a time, so it's an "AB" switch as opposed to the well-known classic "ABBA" switch. That's fine by me as I never had a second drive in the 80s.

Rabs will put it on Github so that anyone can build it.
Is that switch working ok with CPC+ line (I have 6128 plus)?
Title: Re: Who would add a switch to my Gotek cable (to short pins 11/12 as an A-B switch)?
Post by: Rabs on 08:51, 23 June 25
Quote from: Solo Kazuki on 07:07, 23 June 25Is that switch working ok with CPC+ line (I have 6128 plus)?

Sorry, the small PCB I made for Jonathan is only for the original 6128 and not the 6128 Plus, which has a Centronics connector.

However, Drive Select 1 is available on the 6128 Plus connector, see Connector:2nd disc drive (CPC664, CPC6128, CPC6128+) (https://www.cpcwiki.eu/index.php/Connector:2nd_disc_drive_(CPC664,_CPC6128,_CPC6128%2B)) or DIY Floppy Drives (https://www.cpcwiki.eu/index.php/DIY:Floppy_Drives).
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