Re: Questions about IWM

["Henry" <apl2research(at)comcast.net>]

Hello Linards.

When I finish the schematic to the Apple 3.5 Drive Controller I'll post a 
link to it so everyone can see what's going on.

It's actually quite a 'simple' card.  There's the 65C02, SWIM and three 
PLD's.  The rest is standard logic.  We know how the 65C02 works, so the 
only 'real' mystery is the SWIM and the PLD's.  I've been able to crack one 
of the PLD's and don't think the rest will be any issue.  I first want to 
document the cards layout further before I start to tear it apart anymore. 
I also want to be able to dedicate a few weeks worth of time to the project 
also.  Right now tax time has been in the way.


-- 
Henry S. Courbis
www.GSE-Reactive.com
Apple II Series Legacy Hardware - Come take a look at what we have to offer!

"Linards Ticmanis" <ticmanis@gmx.de> wrote in message 
news:443a3c0b$0$18278$9b4e6d93@newsread2.arcor-online.net...
> PZ wrote:
>> IWM's are available in quantity from surplus chip vendors.  Its amazing
>> how long some of these dated chips hang around in inventory.  This is
>> how Henry got a track on SWIM chips.
>
> Good to know. Maybe I can find a vendor that doesn't want me to take 1000 
> of them at the least.
>
>> As far as cloning the Universal Controller, this might be an easier way
>> to go rather than trying to do the whole SuperDrive controller.  Then
>> if someone ever gets around to releasing a USB card, 1.44 firmware is
>> all that would be needed for 1.44M floppy capability.  I think the
>> complexity of these projects arise when the designers try to mix GCR
>> and MFM might be much easier to keep them seperate.
>
> That's what I figured. The Superdrive card seemed to be a bit above my 
> skills.
>
>> There is one additional piece of custom logic on the Universal
>> Controller, I don't know if thats a chip thats sourcable or not.
>> However its likely that its something that can be found in other
>> hardware, for a one-off project.  I'll try to get more info.
>
> Thanks! If you (or anybody else) could come up with a schematic and/or a 
> set of photographs that are good enough to figure things out, that would 
> help too of course; it's a bit hard to clone a card you can't get a hold 
> of...
>
> (But of course this is only an idea at the moment, maybe it'll come to 
> nothing. So don't hold your breath, and don't go out of your way for this 
> just to be nice.)
>
> -- 
> Linards Ticmanis