Daisy Chaining External Drives

[Djay]

Could there ever be a problem daisy chaining external drives that are the same make and model?

Assuming that both drives have no issues separately ...

[davideo]

There shouldn't be as long as you've got enough beef in your power supply to run them and that you have no more than a total of four floppy drives (including internal ones).

Dave G

[Djay]

Originally Posted by davideo

There shouldn't be as long as you've got enough beef in your power supply to run them and that you have no more than a total of four floppy drives (including internal ones).

Dave G

cool thanks for the info

[prowler]

The recommendatrion is that no more than two external floppy drives are daisy-chained from your Amiga.

No matter how beefy the PSU might be, the supply current still has to pass along the printed tracks on your Amiga motherboard - hence the recommendation.

[Djay]

Originally Posted by prowler

The recommendatrion is that no more than two external floppy drives are daisy-chained from your Amiga.

No matter how beefy the PSU might be, the supply current still has to pass along the printed tracks on your Amiga motherboard - hence the recommendation.

The most i have ever had connected at one time is a dual drive, which i "lost" to my brother's friend sometime ago...

I read quite alot about power issues with using extra hardware, i currently have a standard PSU with my A1200, which has an CF HD, Accelerator and external floppy attached...

... so far not probs, so i am wondering what kinda stuff tops the output power of the standard PSU and forces you to go with a beefier one?

[roy bates]

hi,040 and overclocked 060 and ppc based cards needs beefy power supplys.

[StingRay]

Originally Posted by prowler

The recommendatrion is that no more than two external floppy drives are daisy-chained from your Amiga.

Where is that recommendation from? The Amiga hardware can handle 4 disk drives without any problems. I had 4 drives connected to my A500 for years (df0: plus 3 external drives) and there was not one single problem.

[Toni Wilen]

It was Commodore recommendation (it was in some manual, don't remember as usual..) but probably only because first Commodore's original external floppy drives were quite power hungry (and crappy too) and there was different wattage power supplies. (For example not all A500 supplies are the same, always check the label!)

[roy bates]

Originally Posted by Toni Wilen

It was Commodore recommendation (it was in some manual, don't remember as usual..) but probably only because first Commodore's original external floppy drives were quite power hungry (and crappy too) and there was different wattage power supplies. (For example not all A500 supplies are the same, always check the label!)

id have to agree,although the person who asks has a 1200,which we all know is a very feeble supply,some 500 supplys are three times the output.

[prowler]

Originally Posted by StingRay

Where is that recommendation from? The Amiga hardware can handle 4 disk drives without any problems. I had 4 drives connected to my A500 for years (df0: plus 3 external drives) and there was not one single problem.

Originally Posted by Toni Wilen

It was Commodore recommendation (it was in some manual, don't remember as usual..) but probably only because first Commodore's original external floppy drives were quite power hungry (and crappy too)

Thanks, Toni. I didn't know that it was a Commodore recommendation. I was referring to a Power Computing Amiga PC880B User Manual.

[Boo Boo]

So technically you could have more than 4?
If so in theory if you just kept adding drives with out power supply being a problem where would it end?
Sad arent I

[roy bates]

Originally Posted by Boo Boo

So technically you could have more than 4?
If so in theory if you just kept adding drives with out power supply being a problem where would it end?
Sad arent I

nope,four is the limit for any amiga.

[Jope]

The fifth one will not get a select signal, so it will just sit there sucking power, invisible to the OS and uncontrollable by the Amiga.

[desiv]

Originally Posted by Jope

The fifth one will not get a select signal, so it will just sit there sucking power, invisible to the OS and uncontrollable by the Amiga.

But you could do it???

A-Ha! And they said it couldn't be done..

desiv
(Sorry, vbscripting all day; much prefer bash..)

[orange]

Originally Posted by Jope

The fifth one will not get a select signal, so it will just sit there sucking power, invisible to the OS and uncontrollable by the Amiga.

hm, could we in theory make few more drives work if a combination of select signals was used? like "if sel0=1 AND sel1=1 AND sel2=1 then select7=1"
it would require small 'decoder' in each drive and modification in software, obv.
but can Amiga hardware activate several select signals at same time?

[Jope]

Could be doable. Each external drive would have to be modified to pass through all externally accessible drive selects and you'd have to make each drive's ID setting permanent in addition to having your little decoder circuit in there.

Big box Amigas would require more mods, as DS1 is not present at the external drive connector.

There will be a limit to the length of the bus that the custom chips can drive, though.. I guess buffering the bus from the first external drive onwards might also be a good idea.. :-)

Edit: You could also just choose three lines (SEL POUT BUSY?) from the printer port and feed them to an adapter that sits between DF3: and DF4: to make it easier. This adapter could have the buffers and extra power feeds for the additional drives too.

What a stupid yet compelling project. :-)