Author Topic: Two A: drives  (Read 1019 times)

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Offline GeoffB17

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Two A: drives
« on: 15:14, 16 January 16 »

Just now, my PCW is using a 5.25" A: and a 3.5" B:.  The B: is using a separate power supply.

I have my repaired 3" A: still fitted, but disconnected.

I note from some old adverts (8000+ mag, 198?) that machines were being sold back then with 2 drive A:s, (3" and 3.5") referring so some sort of switch (?), but also the suggestion that whichever drive had a disk in would be active without any need to switch anything.

Anyone know anything about that?   It strikes me as possible that the normal working of the system could allow this, i.e. as long as you didn't expect to use both A: drives at once, the system would happily work with whichever drive was active (i.e. had a disk in and was therefore 'ready').   If this is so, it would be quite easy to adjust the cables and do this.   No problem power-wise, as the B: is separately powered!.


Offline arnoldemu

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Re: Two A: drives
« Reply #1 on: 15:40, 16 January 16 »
I don't have an answer.

On PC, the drive is chosen with a twist in the cable. It is possible the pcw was the same.

Having a switch would be doable too.

If there was two A drives that were active at the same time then they would conflict with each other. The FDC would get confused, one drive reporting not ready, one reporting ready, and both would do seeking and reading.

An automatic switch is possible too, but I think it's going to be a manual switch to say which is active OR a switch to say which is A and which is B.

On CPC, the ABBA switch allows you to choose drive A and B so that you can use a 3.5" drive as A and the 3" drive becomes B.

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