Tetroid Disc Interface and Flp1_

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mselkin
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Re: Tetroid Disc Interface and Flp1_

Postby mselkin » Mon May 03, 2021 10:57 pm

Hi again,

further to my last post, on closer inspection, I see that on a floppy cable(for a single drive), the two connectors actually are on the opposite way, on each end of the cable. I have purchased a connector but I'm still not sure which way it goes?
I would like to crimp on a third connector so that I can create a dual drive setup.
Does it matter which direction the third(middle/second drive) connector is attached?


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Chr$
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Re: Tetroid Disc Interface and Flp1_

Postby Chr$ » Mon May 03, 2021 11:14 pm

On my Tetroid device the red stripe of the cable is closest to the front (I can't find pin numbers on the PCB but it's a keyed plug and only fits that way round) and on the floppy drive that red stripe goes to pin 1. I have, on numerous occasions when swapping things over, had it the wrong way round and it doesn't do any harm, just won't work, obviously.

I'm fairly sure - I did try it once - that if you add a 2nd drive it will need to be exactly the same, i.e. red to pin one, and with no twist in the cable, so one drive would have to be jumpered/solder pads or however it is) to DS0 and the other one is probably already DS1 so can be left how it is. Then you should have FLP1_ and FLP2_. Most cables have a twist for PCs so I had to remove one plug, untwist it and then try to crimp it back on, which proved unreliable because I had man-handled the plug!


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mselkin
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Re: Tetroid Disc Interface and Flp1_

Postby mselkin » Mon May 03, 2021 11:57 pm

Thank you. I think I was getting confused by how the cable moves 180 degrees through the strain relief part.
Am I correct that if you simply laid the cable flat and did not use the strain relief, then all plugs have their key face the same way?
I think it's that simple.
Glad to hear it won't cause damage if I'm wrong, I'm petrified of destroying my tetroid interface or QL.


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Chr$
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Re: Tetroid Disc Interface and Flp1_

Postby Chr$ » Tue May 04, 2021 10:23 am

mselkin wrote:Am I correct that if you simply laid the cable flat and did not use the strain relief, then all plugs have their key face the same way?

I don't have a strain relief, just a plain cable. Whether the plugs all face the same way - I think that must depend on which way round the pin 1 is on the floppy drive(s). I've certainly seen drives with pin 1 on the right or left.


Collector of QL related computers, accessories and software even though I don't really understand how they work.
Original QL's: many (plus quite a bit of other old stuff and 140+ original software titles)
Custom XT cased QL system with Gold Card, Qimi mouse, Hermes and MFM HDD
QXLII card installed in a PC
Q40 and Q68 also present

Ask me about near NOS re-felted good quality Microdrive Carts - many available.
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Pr0f
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Re: Tetroid Disc Interface and Flp1_

Postby Pr0f » Tue May 04, 2021 10:31 am

The idea of the strain relief 'loop' is to take the force when you yank on the ribbon cable to free the connector from it's socket - otherwise you are more than likely to pull the ribbon cable off the plug contacts when yanking it...

I always liked the sockets with the little levers on each side which ejected the plug from the socket for you


Derek_Stewart
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Re: Tetroid Disc Interface and Flp1_

Postby Derek_Stewart » Tue May 04, 2021 10:50 am

Hi,

All the odd pins on the Floppy Disc cable are Ground, the Control lines a re Even.

If the cable is connected the wrong way around this will ground all the Floppy Disc control lines and you will see the Drive LED constantly illuminated.

From experience, incorrect connection does not damage the Disc Drive or Disc Interface, it just does not work.

There are key tabs on the cable connectors to stop incorrect connection. Sometime there is a pin missing on the odd numbered pins to key the cable into the socket of the drive or interface, however, this sometimes is not done, as the standard is a little vague.

Most good Floppy Disc cable connectors have a embossed arrow for pin 1 and the cable has a stripe down the length of pin 1 cable wire.

A more interesting question is is the term for the drive and its media; Disk or Disc ?

Being British, I like Disc....


Regards,

Derek
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Chr$
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Re: Tetroid Disc Interface and Flp1_

Postby Chr$ » Tue May 04, 2021 11:02 am

Derek_Stewart wrote:
A more interesting question is is the term for the drive and its media; Disk or Disc ?


It certainly used to be disc in British adverts and in instruction manuals etc but I've actually grown to prefer disk. Maybe that's the German influence, as here it's short for diskette. I don't think discette was ever a word - that looks wierd!


Collector of QL related computers, accessories and software even though I don't really understand how they work.
Original QL's: many (plus quite a bit of other old stuff and 140+ original software titles)
Custom XT cased QL system with Gold Card, Qimi mouse, Hermes and MFM HDD
QXLII card installed in a PC
Q40 and Q68 also present

Ask me about near NOS re-felted good quality Microdrive Carts - many available.
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XorA
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Re: Tetroid Disc Interface and Flp1_

Postby XorA » Tue May 04, 2021 11:03 am

If the cable is connected the wrong way around this will ground all the Floppy Disc control lines and you will see the Drive LED constantly illuminated.

From experience, incorrect connection does not damage the Disc Drive or Disc Interface, it just does not work.


Yes, and in my experience so many cables and/or drives have the wrong orientation and/or labelling they stopped putting keys on them decades ago :-D


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NormanDunbar
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Re: Tetroid Disc Interface and Flp1_

Postby NormanDunbar » Tue May 04, 2021 1:01 pm

It's disc for me too.


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