Getting a DuoDisk unit working again...

9 posts / 0 new
Last post
Offline
Last seen: 4 months 5 days ago
Joined: Dec 28 2019 - 15:13
Posts: 7
Getting a DuoDisk unit working again...

I came into posession of an Apple IIe with a DuoDisk unit.  It sat for years in a barn and is caked with mud dauber nests on the inside.  As I'm cleaning it out, I've torn down one of the two DuoDisk drives and I want to establsih two things:

 

1.  Whether or not I need to do the DuoDisk mod to the analog board

2.  How to test the stepper motor before putting everything back together.

 

On the first point, I can't establish whether or not the analog board is one of the three that require the mod for preventing disk overwrites.  That is, there is no 676-[]101, 676-[]102, or 676-[]107 marking.  On the back, I see 820-0123, but as I look at schematics, I get the impression that's not the number I'm really looking for...  But I see no other numbers on the PCB like that.

 

On the second point, I've found descriptions of the 20-pin connector, but they are for Disk II or DuoDisks that appear to be different than mine.  The article on Wikipedia describes wire colors which I really couldn't correlate to the connector I have.

 

Any tips or a cache of technical documents I've not yet found?

amauget's picture
Offline
Last seen: 4 weeks 1 day ago
Joined: Jan 3 2011 - 11:34
Posts: 278
Apple duodisk ?

Hi Joel,

It seems you don't have an Apple Duodisk like this one. If it's true, you probably don't need the mod.

Pictures of the case and the analog board would be very welcome to verify.

lefevere's picture
Offline
Last seen: 3 months 6 days ago
Joined: Apr 13 2004 - 20:40
Posts: 59
Number ......

The Analog board is the one inside Drive 1 in the Duodisk. 

You may have to unplug the cable near the back right of the board to see the board's model number. 

Offline
Last seen: 6 hours 59 min ago
Joined: Jul 5 2018 - 09:44
Posts: 488
amauget wrote:

Hi Joel,

It seems you don't have an Apple Duodisk like this one. If it's true, you probably don't need the mod.

Pictures of the case and the analog board would be very welcome to verify.

 

Yeah, it sounds like maybe he has two UniDisk or Apple 5.25" drives.  Those are similar to a Duodisk, but not the same boards in them.

 

Offline
Last seen: 4 months 5 days ago
Joined: Dec 28 2019 - 15:13
Posts: 7
It's a DuoDisk unit.  The

It's a DuoDisk unit.  The board number was hidden well, so it wasn't until I unplugged a few harnesses that I finally saw it.  It's a 676-[][]102...

 

I think that means a resistor needs to get clipped somewhere...

Offline
Last seen: 6 hours 59 min ago
Joined: Jul 5 2018 - 09:44
Posts: 488
joel_graff wrote:

It's a DuoDisk unit.  The board number was hidden well, so it wasn't until I unplugged a few harnesses that I finally saw it.  It's a 676-[][]102...

 

I think that means a resistor needs to get clipped somewhere...

 

Google provides this wisdom from Dr. Steven Buggie:

 

https://stason.org/TULARC/pc/apple2/faq/09-006-What-DuoDisk-mods-are-necessary.html

 

 

 

 

Offline
Last seen: 6 hours 59 min ago
Joined: Jul 5 2018 - 09:44
Posts: 488
Actually I mis-credited that.

Actually I mis-credited that.  The article was by Jeff Hurlburt, Dr. Buggie posted the last comment to it.

 

 

Offline
Last seen: 1 day 17 hours ago
Joined: Dec 19 2008 - 21:01
Posts: 298
The mods are only for hooking

The mods are only for hooking to a IIgs and not a IIe. There should be nothing needed for the IIe.

Offline
Last seen: 1 day 17 hours ago
Joined: Dec 19 2008 - 21:01
Posts: 298
rittwage wrote:

The mods are only for hooking to a IIgs and not a IIe. There should be nothing needed for the IIe.

 

Well, the second one.

Log in or register to post comments