Disk ][ (Notice I spelled it right? :) ) Query...

[Don Bruder <dakidd@sonic.net>]

Hey folks, I'm sitting here wondering...
I've got several physically smashed up, broken-keyboard Apple //es that, 
cannibalized and combined, have morphed to become a total of two 
functional (but one cosmetically hosed, with a big ol' chunk missing out 
of one side of the case) "SuperFat" Enhanced //es. 

I have christened them "Humpty" and "Dumpty", for reasons that should be 
self-apparent, and if I can figure out a way to get 'em up and running, 
and onto my Mac-based LAN, those will be their DNS names :) But I 
digress... 

I've got assorted cards for them, some of which (Super Serial, 80-col, 
ext. 80-col, AE 256K - Most anything that's marked, anyway...) I can 
identify, and in most cases, I know their purpose for existing. Some 
leave me utterly clueless. Others, like the stack of Disk][ controller 
cards, leave me in an in-between state. I know EXACTLY what they are, 
and I know EXACTLY what their intended purpose is. Unfortunately, there 
were no Disk ][ drives in the dumpster I dove for these units. The local 
"not-really-the-Salvation Army store, but a real similar concept" 
operation used to have a butt-load of them due to an arrangement with 
several local school districts. Alas, that was last year. Now they only 
seem to have the newer Unidrive/UniDisk 5.25 and 3.5 units. Now what I'm 
wondering is this:

I have another disk controller card, labeled 
"I/O Controller 655-0101-C".
Compare that with the Disk ][ card, which is labeled
"Disk ][ Interface Card 650-X104-8"
 
After carefuly examining both of them, and sketching out a set of crude 
but reasonably accurate schematics, unless I'm a *WHOLE LOT* stupider 
about electronics than what I think I am, I find that they are identical 
cards, with the exact same circuit, with the exception of the fact that 
the X104 card connects with two arrays of 2x10 Molex-type connector 
pins, and the 0101 runs the same traces to a single, flat 20-conductor 
rainbow cable header (With one pin of the connector being N/C), and the 
rainbow cable terminates as a female DB-19 connector.

When I say these cards look identical other than the connections, I mean 
right down to the PROM chips (On both cards, they're Apple part 
#3410027-A for P5, and 341-028-A for P6, both bearing a 1981 copyright 
date and the "P5A" and "P6A" notations, respectively) bypass capacitor 
types and values, support chips, the works. There's some slight 
trace-routing differences, but the ends of the traces, regardless of how 
different their paths might be in between, hook up to the same pins on 
the same chips at both ends, with the exception of the "jump off the 
card" connection point, where there are substantial differences to go 
along with the substantially different physical connections being used.  

Does anyone know if this means that I should be able to hook up the male 
DB-19 end of a UniDisk or UniDrive 5.25's cable to the X104 (Disk ][) 
card through a properly wired (probably designed and fabbed by me, since 
I suspect my life ain't charmed enough to have it be an off-the-shelf 
item) molex-style header<-->DB-19 adapter, and expect to find myself 
looking at a functional card/drive combination? 

Or am I just plumb out of my mind to be coming up with such a 
hare-brained scheme? 

Anybody care to weigh in with an opinion on this concept? Yes? No? 
Maybe? "You're outta yer freekin' head"? "Where can I get some of 
whatever you've been smoking"? "If I send ya 20 bucks, will ya make me 
one?" offers? Something else? If so, please don't hesitate to speak up. 
I'm honestly eager to hear some input on the idea from other people, 
whatever that input might be. If it's already been done and published, 
that's fine... Point me at it, please?

-- 
Don Bruder -  dakidd@sonic.net <--- Preferred Email - unmunged, SpamAssassinated
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