10 replies to this topic

[potatohead]

Was just wondering about this. I may want to run a few things that require a second disk to really be functional. Right now, I've got the Disk II controller card, and one of the newer style drives with the 20 pin connector on it.

How does one add a second disk in that configuration?

Is it mandatory to get a Duo Disk, or???

[HuckleCat]

Wait, do you mean one of the newer UniDisk 19 pin drives? The 20 pin drives are the old ones that connect straight to the board, not a connector affixed to the back of the machine. If you mean the newer ones where the card has a cable that populates all of the 1st drive pins, and one of the 2nd drives pins, then to add a 2nd drive you connect it to the back of the first drive.

In any case, you shouldn't have to get a duodisk.

[desiv]

In your other thread, you said you got this controller?
eBay Auction -- Item Number: 380338950684

So you just need another cable going to the second drive..
Each drive gets it's own cable.

Opps.. Getting my people confused here..

Sorry..

Does your controller have 1 or 2 drive connections?

desiv

[Keatah]

perhaps this can help. and what model(s) are your drives? Model numbers please.
 apple_floppy_disk_drives.pdf   127.3K   16 downloads

And here is a pin-out chart.
http://en.wikipedia....II_Cable_Pinout
Please study it and become familiar exactly what we're working with. Note the different compatibility options, what is, and what isn't.

Maybe you need this? I don't know!?! But it's easy enough to make..
http://www.connectwo...in/rrdata/L1565

Here are more choices, in case I guessed wrong.
http://www.connectwo...05MCAODisk.html
(I also notified them about the wrong picture for the L1560)

Once I am confident I know your exact hardware, we can either make U a cable, or purchase one, or do something! Please report back with the model #'s of both the drives. And the controller card. Also, what model computer? II+ or //e ??

I suspect you have 2 drives, both made by Apple, right? -- One with the 20-pin block connector & ribbon cable, 2 rows of 10 pins each. And another newer model, with a D-19 connector and round cable. I will also assume these are 5.25 and rated for 140K capacity. Furthermore, The drive with the round cable will have only one connector, that's to the computer. No pass-through, no nothing!! Well, if that's the deal, then you can pilfer a cable from a shitty defunct drive and wire it in. Or build your own "converter". It is electrically compatible, just a physical difference in layout & connector style.

And you have a standard Disk II controller card? Like this?


But not like this..

Edited by Keatah, Sat Oct 8, 2011 10:59 PM.

[Keatah]

For those of you that find stuff like this interesting, it is fascinating to note that Woz built the Disk ][ Controller card with a processor on it! Yeh, it's a simple state machine designed to run the logic that controls the flow of i/o bits. Bits that are to be shifted in and out of the drive's analog circuit. It was made of the LS323,259,174 chips - these basic flip-flops and registers and latches. That and the PROM.

Imagine that, a processor consisting of a couple of hundred transistors, at most, and 256 bytes of ROM. It was the interaction between the logic gates and shape of the program that made those chips do far more than they ever could on their own. In this case, the saying of - "The sum of the whole is greater than its parts." is a serious understatement!

Logic gates turned into a processor, by adding a PROM! Wow!

There are some books out there that explain this great detail. Incredible!

Edited by Keatah, Sat Oct 8, 2011 11:24 PM.

[potatohead]

I'll get a inventory when I can. This is a good discussion to have.

Yes, I've read the very detail tech book on the //e. Author escapes me right now, but it was one hell of a read. Woz really did have talent in that area, applying simple tech to difficult problems in elegant ways. Love it.

[Keatah]

I remember now, it was Sather. Jim Sather. It is an incredible read! The author spent many an hour with Woz. Information flowed from Woz to Jim to you! Information coming rite @ U, directly! This sort of tech-writing was so in-depth the publishers of the physical book, which you'd buy at the store, would just throw up their hands and say go for it! Beyond grammar and printed layout styling (to make stuff fit the pages) they didn't adulterate any of the info. Nice. Not like today, where a book needs to be reviewed a hunnert-times for political correctness and corporate secrets.

The two books, understanding the Apple II (and //e) are here for you to download.
http://mirrors.apple... Project/Books/

It is also amusing to note that the "Apple II Circuit Description", also here, sells on ebay for almost $1000.00 ~~!! WTF? Well I am pleased to announce the auction has been running for over 2 years and no buyers! Assholes!! Just who do they think they are! That's as bad as a Disk ][ controller card going for 49.95 or a MicroModem for $400+ Shitheads..

[potatohead]

YES!! That's the guy, and I have that book for the //e. Just finished it a coupla weeks ago. Awesome really. He's got a great flair for writing those kinds of things in ways that are entertaining and educational. I'm very seriously thinking about making a project card or two, so I can interface some stuff to the Apple. Apple Interfacing is a good book too. I've got both.

As for the prices, yeah. Just gotta watch for deals and ignore the clowns.

Nice link on the PDF's. I'm snagging a copy for my laptop.

Edited by potatohead, Sun Oct 9, 2011 12:54 PM.

[magnusfalkirk]

Potatohead,

You never did say what your controller card for the IIe looked like. Does it have a cable that attaches to the back of the computer that the drive plugs into or does it have two sets of pins, one above the other, that the ribbon cable plugs into? Which card you have makes a difference as to what drives you need and how they plug into the computer.

Dean

[potatohead]

Mine says "Apple 5.25" Disk Controller", and it's got one colored ribbon that goes to a back mounted connector. I never looked at my Disk drive closely, but it has the daisy chain connector on it.

That answers my question nicely. Need another of that kind of disk, or some adapter cable / hack for a older Disk ][ it seems. Thanks for the info. I just got back to where I could look the machine over.

[Keatah]

I have not ever used this specific cable, I made my own.. If you want something pre-made, then this should let you connect a Disk II (metal case A2M0003) to a Unidisk (plastic case w/daisy-chain connector A9M0104). I believe it will let you connect a Disk II (metal case A2M0003) to your controller card as well.

http://www.e-4.net/c.../standard/L1564
http://www.iec-usa.com/l1564.html
http://www.connectwo...in/rrdata/L1564

Today's trivia: Drive 1 and Drive 2 connector pins on the original Disk II controller card are all in parallel except for pin 14, which is the drive signal line. This line selects where the data and control signals go, to Drive 1 or Drive 2. This is why you can't read/write simultaneously to both drives. You can switch back and forth quickly, giving somewhat the illusion you *are* reading from one disk and the writing to the second disk at the same time.

For those of you wondering what a DISK II drive sounds like - here's your chance to get a listen.
 Apple_2_Disk_Drive_Sound_Simulator.zip   794.71K   12 downloads

Edited by Keatah, Mon Oct 10, 2011 12:08 AM.