4 X Floppy Drive Support on Internal Connector?

[DrDekker]

Since there are four drive selects (DS0-DS3) on the internal floppy drive connector - does this mean that (in theory and a bit of jiggery-pokery) four drives can be installed on this connector?

I would assume that four drives would be stretching it a bit - but how's about two drives?  A possibility?

TIA.

[AndrewBell]

I know that 2 internal drives is possible by using an appropriate cable, but I've never heard of 4.
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Nevada dispensary

[doctorq]

Two drives is possible, take a look here.

[LoadWB]

I know guys that did this with the TI-99 system.  So long as the driver can handle the load, the port provides DS0 through DS3, and you have the right cable or the right jumpers set on the drives themselves, then this is possible.

I think most drives will tri-state their I/O when not selected, the the load issue should be moot.  Should.

[DrDekker]

Thanks for the responses guys - really appreciated!

@ doctorq - thanks for the link.  A second drive on the internal connector would be a really neat solution (and all I need really) and I'm now wondering if a DIY hack can be done based on the one in the link.  I'll investigate further.....

[doctorq]

@ doctorq - thanks for the link.  A second drive on the internal connector would be a really neat solution (and all I need really) and I'm now wondering if a DIY hack can be done based on the one in the link.  I'll investigate further.....

I think you need the chip that's on the PCB board, but I don't know for sure. You can also take the easy solution and make me an offer on it :-D You have already seen a picture of it.

[AndrewBell]

DrDekker wrote:
Thanks for the responses guys - really appreciated!

@ doctorq - thanks for the link.  A second drive on the internal connector would be a really neat solution (and all I need really) and I'm now wondering if a DIY hack can be done based on the one in the link.  I'll investigate further.....

I think I have one of those cables somewhere, it's yours if you want it.
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YAMAHA V8 ENGINE

[Hodgkinson]

Hmmm. I did a bit of research into this, particularly with regards to using 4 PC floppy drives on a A1200. I seem to remember that only DS0 and DS1 are present on the internal connector, and that the external connector has similarly a reduced number of lines.
I believe you need to connect to a IC on the motherboard to get the full DS0 to DS3 in a *decent manner*

As for using PC drives, I gave up after coming to the conclusion that having any less than 4 drives, due to certain required pull-up resistors due to OC outputs on the drives, could result in unpredictable behaviour.

Hodgkinson.

[Zac67]

You'd have to cut the drive select lines for the drive 3&4 cable and connect them to the normally external drive selects. Is it worth it?

PS: plus generate the motor on signals, but you could drive all with one signal

[AndrewBell]

@DrDekker

The floppy cable I have isn't the one with the PCB connected. It has 3 floppy connectors, and wires 10-16 are crossed over between the last 2 connectors. I can't be certain, but I seem to remember it being supplied with my Micronik HD floppy, which has a jumper on the drive to select between DF0 and DF1.

I did a quick test, and the drive sort of works on this cable. I say sort of, because I think the drive has to be set to DF1. To do that I would need to dismantle the drive, so it's staying as DF0.
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Ford P Platform History

[Orjan]

AndrewBell wrote:
@DrDekker

The floppy cable I have isn't the one with the PCB connected. It has 3 floppy connectors, and wires 10-16 are crossed over between the last 2 connectors.

Uhh.. Isn´t that what a regular floppy cable looks like?

[AndrewBell]

Orjan wrote:

AndrewBell wrote:
@DrDekker

The floppy cable I have isn't the one with the PCB connected. It has 3 floppy connectors, and wires 10-16 are crossed over between the last 2 connectors.

Uhh.. Isn?t that what a regular floppy cable looks like?

No idea, I've never seen any other Amiga cable for 2 floppy drives.
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Starcraft 2 Replays

[Hodgkinson]

There’s a guide for using a PC floppy drive on an A500 here, if it’s of any use to anyone:
http://www.ianstedman.co.uk/Downloads/downloads.html

The bit that worries me is that in the ablve diagrams with the PC drive, some of the Amiga input rails are active high, there' normally held low by the O/C PC floppy drive outputs, and there’s a pull-up resistor to that line in the circuit, thus meaning that when no drive was present, the line would be active high.
On the other hand, when using an Amiga drive, the line would be inactive low when the drive isn't present as the high signal coming from the floppy drive signal rail is no longer present.
(NB. This argument would seem to apply to any drive that might not be present out of DF0 to DF3, regardless of the presence of other drives, through the action of the drive select lines).

At least I think this is the reasoning that I came to; it’s a while since I thought about the problem. Due to this, I decided to shelf the multi-PC floppy controller project I was working on (Don’t like the idea of *odd* rail levels confusing the system) and stick to the directly compatible (Just the 1 internal drive on the A1200, as yet) Amiga drive.

Hope someone can follow the reasoning behind this possible *problem*,
Hodgkinson.

[DrDekker]

Well - I've sort of got two floppy drives working on the internal connector using a simple cable hack.

DF0: works perfectly, whilst DF1: recognises disk changes but can't read the disks.  All I get is 'DF1?'.

When clicking on the DF1: icon I get a 'no default tool' error.

Any ideas what the cause could be?  Would the signal inverter/RDY hack be the solution?

TIA.  

[Lemmink]

Erm whats so special about just two internal floppys on the internal port. Every A2000/ A3000(T) / A4000(T) has the appropriate cable to connect two internal drives you just have to jumper the second one to DF1 that`s it. I don`t see why this should not be possible for an A600 / A1200 as all Amigas should be the same when it comes to that.