The Sinclair QL Forum

Hi all,

I'm about to embark on connecting a second 3.5 inch floppy drive to my existing system, and I'm having doubts as to the proper arrangement of jumpers and cables.

For the first drive, things were pretty straightforward: straight portion of PC floppy cable; jumpers ds1 -> ds0, DC -> rdy. Everything seems to work fine.

For adding a second floppy, it looks like I need to untwist the second half of the floppy cable, swap wires 10 and 12 on the cable (once straight, that is). Then modify the jumpers on the second drive as the first.

Does that sound correct? Is it possible to buy a cable that's already setup like this? Or are there step by step guides on how to modify a PC floppy cable? The 34 pin connector doesn't look like its meant to be taken apart...

Thanks for any advice...

Adrian

Hi Adrian,

It seems that both of your drives have jumpers (which makes it easy).

Just keep a straight cable throughout - no twists.

Then just set the jumper on the second drive to DS1 (probably what it was already) and DC->ready as on the first drive.

RWAP wrote:Hi Adrian,

It seems that both of your drives have jumpers (which makes it easy).

Just keep a straight cable throughout - no twists.

Then just set the jumper on the second drive to DS1 (probably what it was already) and DC->ready as on the first drive.

Well, when I say jumpers, it'll be solder jumpers, so not too bad I guess.

That's a good idea on keeping the new drive as ds1. I'll add labels to both drives showing whether they're ds0 or ds1. I can't see my using them for anything else really.

Did you have any idea where to get hold of straight through 34 pin connectors? I'm wondering whether to snip a twisted cable and solder it back up to negate the twist...

Thanks,

Adrian

I will have a look tomorrow - I may have a couple of spare straight cables....

RWAP wrote:I will have a look tomorrow - I may have a couple of spare straight cables....

Thanks Rich, that'd be brilliant.

I have found the cable - see PM.

It may be too short for you - the distance from the interface connector to the first floppy drive connector is 12" (30cm)

RWAP wrote:I have found the cable - see PM.

It may be too short for you - the distance from the interface connector to the first floppy drive connector is 12" (30cm)

Thanks Rich.

Cable received and tested: all working fine. I now have a working twin 3.5 inch floppy system, correctly responding to flp1_ and flp2_ commands.

Adrian

Great - glad to help

Adrian wrote: Did you have any idea where to get hold of straight through 34 pin connectors? I'm wondering whether to snip a twisted cable and solder it back up to negate the twist..
Adrian

In case of emergency you may simply cut a classic hard disk flat cable. It works pretty well