I just wonder how many external floppydrives a CDTV can drive ..
I read that the powersupply could handle ONE external drive without extra powersource ... ??

Is this the case also on A1200 or A500 ? ONE and ONE only ? With exception of selfpowered drives ?

I know the A500 can handle 3 external drives technically, but this power issue got me worried,
since I tried to run a Datalux drive daisychained to another drive I have (Amitech) and it didnt work..
The Datalux branded drive ran by itself though it seems ..

I had another drive connected on the Amitech and I dont really recall having any problems with that in the beginning .. All this is on a CDTV.

I have a modified PC PSU for my A1200, does that help if I would try daisychaining on that machine ?

@Mr_DBUG

How much power do they draw? It can´t be that much. How many you can have connected at the same time also depends on how much other periphals you have connected (turbocard, HD and else) and which power supply you have.

@Niolator

I dont really know how much power they draw

Got them used from a German on eBay

@Mr_DBUG

You could try them. But don´t blame me if something brakes. Doesn´t it say something underneath the drives about amps and volts?

@Mr_DBUG

Each drive would use less than 10W (more close to 3-4 watts) so you should be safe using a PC power supply for several external floppydrives.

Not sure about the original powersupply of the CDTV though.

The A1200 and A500 has weaker power supplies.

Check the following great link for more info:
Amiga Power supply guide

Last edited by Smurfen on 04-Aug-2010 at 10:49 AM.

@Smurfen

If you really want power I think AmigaKit has PSU´s that fit desktop A500-1200 that delivers up to 200 watts. i don´t know if CDTV has the same connectors as those though.

Last edited by Niolator on 04-Aug-2010 at 11:41 AM.
Last edited by Niolator on 04-Aug-2010 at 11:40 AM.

@Mr_DBUG

Quote:

Mr_DBUG wrote: I just wonder how many external floppydrives a CDTV can drive .. I read that the powersupply could handle ONE external drive without extra powersource ... ?? Is this the case also on A1200 or A500 ? ONE and ONE only ? With exception of selfpowered drives ? I know the A500 can handle 3 external drives technically, but this power issue got me worried, since I tried to run a Datalux drive daisychained to another drive I have (Amitech) and it didnt work.. The Datalux branded drive ran by itself though it seems .. I had another drive connected on the Amitech and I dont really recall having any problems with that in the beginning .. All this is on a CDTV. I have a modified PC PSU for my A1200, does that help if I would try daisychaining on that machine ?

The Amiga hardware database (amiga.resource.cx) states for the CDTV:
Quote:

The floppy drive controller supports up to four devices, all connected externally.

(although it is not infallible, and I'd trust the product manual if the two are in conflict)

Anyhoo, there are three issues here:

1) Can the Ax00/CDTV address multiple floppy drives?

The Ax00 models can (4 with the internal drive).
Don't know with the CDTV, but I'd imagine it uses the same addressing space as the other models.

Potential consequences if it goes wrong: the drives are not recognised - CDTV may not boot whilst drives are connected.

2) Does the Ax00/CDTV have sufficient overall power to supply the drives?

The Ax00 models do, however as pointed out this can be borderline when you have other power-drawing peripherals attached (hard drive, pcmcia card, accelerator card, clockport devices, etc).
The CDTV probably does, as it can also be expanded be internal peripherals (scsi, processor expansion, etc). Again, if you have it pimped out you may start to run short of available power.

Potential consequences if it goes wrong: temporary system instability/non-booting whilst the peripherals are connected.

3) Can the external drive port supply enough power through it's supply +12V/+5V lines?

The Ax00 models can (see pinout with power rating here), since they are designed to have multiple drives daisychained. I've personally used three external drives without any problems at all, and I'm sure that if there were a commonly-occuring problem, it would be well known after all these years.
The CDTV may not be able to supply sufficient power through the port if they are not designed to do so (although I've been unable to find a CDTV manual/pinout online to check).
Potential consequences if it goes wrong: Worst case is burned out supply lines or burned out SMD resistors, it just depends what rating the supply lines have been designed to.

You could avoid this risk by supplying +12V and +5V to the drives from an external power source, and disconnecting these lines from the connector to the CDTV (relatively easy hack to accomplish with a screwdriver, a psu & a bit of patience).

Supplying a greater power source globally to the Ax00/CDTV (such as a PC psu through the CDTV/Ax00 power connector) would eliminate issue #2, but not issues #1 or #3.

Wrt to the daisychaining issues you had, it could be that the cables connecting to the 'through' port of the Amitech drive (assuming that to be the first drive attached) were damaged. You may wish to try daisychaining them again in the reverse order to eliminate this possibility. Also (stupid as it sounds) check any 'on/off' switches on the back of the drives are set correctly - they're easy to miss.

Good luck & happy hacking



Rich

EDIT: Spelling,grammar, punctuation.

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@Mr_DBUG

I have a switching power supply for my Amiga 500 because at the time they said it couldn't handle more than an external drive or two. My external drive doesn't have a power supply because it gets fed power from the computer. I've never had a problem with just one external drive hooked up to the Amiga 500 but I remember when my brick power supply died for the Commodore 64 and I had to wait about a week for a replacement. I wanted to make sure I wasn't without a power supply and now we're here twenty five years later...

@all

First, many thanks for replies !

I have for my A1200s a AmigaKIT modified PC psu each.

So I understand that I would likely be safe to connect one or maybe ideally two,
external drives there then ?

On my A500 I use a A1200 PSU since I dont have any expansions on that one,
would that be likely enough to drive one external drive ??

(That A1200 psu came with my NOS A1200 from AmigaKIT

For the CDTV I will investigate further ! I believe technically its the same as an A500+ (?)
Id be doggone to know what powersource they put in it though.

One more thing:

Is it safe to stack these floppydrives ? Or can that have unwanted magnetic side-effects ?

@Mr_DBUG

Well, seeing as the drives are made to be daisy chained with up to three connected to a machine, provided the PSU is up to it I really doubt there will be any other problems. Yes, it's safe to stack floppy drives - they generally incorporate shielding to protect themselves. Besides, the strength of the magnetic field used by a floppy drive is really tiny.

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@Mr_DBUG

Quote:

One more thing: Is it safe to stack these floppydrives ? Or can that have unwanted magnetic side-effects ?

Take an old floppy you don't need anymore and take a kitchen magnet and put them together. Then read the disk in your computer. The disk should still work. It is a myth that keeps repeating itself because people don't know how magnetism works.

@Chuckt

Erm, I think you will end up with errors if the magnet is strong enough. Stick the disc near the back of a a speaker and see if you can read that!

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