Superdrive FDD compatibility

[RickNel]

On another forum I've been asked whether a 3.5" 1.4mb superdrive (as standard in SE-Mac II) can be connected to a Plus logic board.

My assumption is that the earlier ROMs will not recognise a Superdrive, even as a 800k drive. Mac docs do not suggest it is possible.

Has anybody tried this?

Rick

 

[CelGen]

I've probably done it to an SE and it just sees it as an 800K drive.

 

[RickNel]

I decided to try this out rather than rely on distant memories.

I plugged a known-good Superdrive into the internal floppy cable of my 512ke. The compact would not boot, and made those puff-puff-puff noises you hear from the analog board when something is pulling wrong voltage or overcurrent.

Either there is a different cable pinout (same 20-pin IDE plug), or the superdrive takes some different power requirement.

Anyone know the difference?

Rick

 

[Macdrone]

Rom difference maybe? Might try SE roms.

 

[volvo242gt]

I have noticed that the SuperDrive equipped Macs I've opened have a red stripe on their floppy drive cable, whereas the 800k machines seem to have a yellow stripe. Guess we'll see what happens on FrankenIIx when I get that machine going. Got a SuperDrive plugged into the original yellow stripe cable.

*EDIT* Just tried one in my 512Ke... *BIPPP* Then, display with a blinking question mark and the usual Sony floppy drive stepper motor sound. So, something may be wrong with your 512KeD, Rick... Or, maybe the drive went boobs up after previously testing it.

-J

 

[Macdrone]

My 128 wont see the superdrive (either of them) , my 512K with plus roms does but as 800K.

 

[volvo242gt]

Which is what it's supposed to, since the 128K 512Ke/Plus ROMs only support the IWM controller, not the SWIM controller used for the 1.4MB capacity.

-J

 

[RickNel]

I have the same setup as Macdrone, but different result. The superdrive works fine in my IIsi, and the 512k boots fine with my 800k drive in it. Voltages on the floppy connector are within spec. Suspicion turns to the analog board caps in the main power rails - maybe high ESR -> not enough transient current, if the superdrive happens to pull more at boot time than the 800k? Something is telling the sytem not to boot with that drive connected. Mac Bible doesn't cover anything like that.

Not sure if Volvo's yellow stripe indicates anything - it's usually just to indicate correct orientation for the plug. Though on multicolor .power harnesses yellow=12v, red=5v. The Mac FDD 20-pin connector has both 5v and 12v pins

Rick

 

[onlyonemac]

If I remember correctly, yellow striped cables had a cut wire and red ones didn't (or equaly possibly vice versa).

 

[RickNel]

Well if there are different cable configs it would suggest there may be a different pinout - possibly relating to power rails. But both my IIsi and my 512k have red-striped cables. I seriously need some authoritative pinout info on this - any suggestions for sources?

Rick

 

[Macdrone]

Could just switch the cable and see.

 

[mcdermd]

If I remember correctly, yellow striped cables had a cut wire and red ones didn't (or equaly possibly vice versa).

Yep. It should be pin 9.

viewtopic.php?f=7&t=19242#p181869

 

[volvo242gt]

Yep. It should be pin 9.

viewtopic.php?f=7&t=19242#p181869

...and pin 20.

-J

 

[mcdermd]

Right you are!

 

[volvo242gt]

*chuckle*

Speaking of Superdrives, just built an external Superdrive out of an A9M0106 Apple 3.5 Drive and a Superdrive mechanism... A lot cheaper than getting the original external Superdrives... IIci recognizes it as one, and it still works as an Apple 3.5 Drive on an Apple II series machine or a non-FDHD capable Mac.

-J

 

[Brett B.]

Speaking of Superdrives, just built an external Superdrive out of an A9M0106 Apple 3.5 Drive and a Superdrive mechanism

Ha! I just did this same thing last weekend. In fact I tried doing it twice to a pair of those drives I pulled out of a school auction sale years ago, and in the process found that one was already converted over (although the drive needed a lube job anyway.) Pretty cool because now I've got one good spare 800k drive and two Superdrives, one for the SE and one for the SE/30.

 

[volvo242gt]

Ha! I just did this same thing last weekend. In fact I tried doing it twice to a pair of those drives I pulled out of a school auction sale years ago, and in the process found that one was already converted over (although the drive needed a lube job anyway.) Pretty cool because now I've got one good spare 800k drive and two Superdrives, one for the SE and one for the SE/30.

lol, guess we both were thinking the same thing last weekend. It's usually the first thing I do to an A9M0106, if I happen to have a later mechanism lying around. Still works great with a IIgs or a //e that has the Laser UDC card.

-J