What is this sorcery!!! (HUGE Dove RAM chips)

[unity]

I dont think I have ever seen a 30-pin module for a Mac this large before....

Four are maxed out. Four are barely populated, which seems odd. These came in a Mac IIx. Not sure what size they are yet, I suck at identifying RAM. Im going to try a jump start and see if she powers up. If not then I will have to try these in my II.







View attachment 5437

 

[miniMOJOman]

lol that looks ridiculously/awesome cant decide which haha

 

[Byrd]

Haha I thought I'd seen massive SIMMS before in Q950s etc. but those things are crazy!  Must have had a sale on low-capacity RAM chips

 

[TheWhiteFalcon]

They kinda look like the IIgs ram card.

 

[Unknown_K]

I seen those kind of things in old Macworlds but never seen one in the flesh. IIx machines needed composite RAM so somebody came up with these monsters. They are probably 4 or 8MB can't read the chips.

 

[unity]

Ya, other than physical size I dont think they are anything impressive capacity wise.

The IIx is toast, the worst cap damage I have ever seen. No battery damage. Power supply comes up, but nothing from the board. Can I try these in my II? Im not sure what other Mac this would even fit in since the modules are so one-sided in length.

 

[Gorgonops]

Those things are very possibly the best crazy-simms I've ever seen. We're all familiar with "SIMM Savers", would you call those "DIP Savers"?

 

[unity]

Geez, they dont even fit in the IIx I think. There are nylon spacers under the drive tray. Wonder how that would have affected the floppy alignment.

 

[uniserver]

i agree this is cool and puzzling all at the same time.

 

[unity]

Well I think the IIs memory cap is kicking in or something. I put the modules back in the same order as they were in the IIx. But I started with the four less populated boards. I got 4MB total. So guessing those are 1MB boards.

But when I installed the additional boards, I ended up with 8MB total. So they also registered as 1MB boards even though they are fully populated.

There are some blue jumpers. Only the first board had two. I removed one, same thing. But either these jumpers have something to do with it or the Mac II with its 20MB limit is just not seeing them right. But this should be 20MB of RAM in the first place.

If I boot with only the fully populated ones, I get a grey screen then the video goes out.

 

[unity]

Figured it all out. The IIx would probably read all 20mb.

But the II, which is all I have to test these with right now, is a very early first run. It has an HMMU and needs an PMMU upgrade to address more than 1mb SIMMS in bank B. Otherwise 8mb is the max. The kicker is the socket. One has to pull the board and look under. 132 through hole pins is good for this socket. Around 70 is bad, that means the socket is HMMU specific and will not accommodate an PMMU upgrade. And since my board is early, I will not bother even looking. Apple did have a swap program in place for these boards. This also explains why there are a couple revisions for this board and why so few originals exist. (A shame since the originals used solid caps, no electrolyte leakage!)

One work around is to install an 030 upgrade card. I think the 030 has a built-in memory manager and can address the extra RAM - up to 128mb.

But since I can see 8mb, odds are they all work. Now I just need to get a working IIx board to put these back in their proper home.

 

[CC_333]

Hmm, I happen to have an extra Mac IIx board. You can PM me if interested.

c

 

[Danamania]

I have no words...

these things put my Genesis' RAM cards to shame for sheer huge quirkiness ( see https://www.flickr.com/photos/71473458@N00/ )

 

[unity]

There, problem fixed! 030 upgrade! I crossed my fingers that my HMMU socket was not specific. I really expected it to be since my board revision is one of the firsts. But I guess for once when Apple said "a limited number of machines were affected by...", they actually meant it! lol

So once I was good there, I pulled the 020 and put in the Daystar Mac II adapter with 030 upgrade card. It amazes me that old stuff like this that has been removed, stored then reinstalled still works.

Fun stuff!

So I think I will just leave this RAM in there. I am certain that this 20MB kit was originally for the Mac II and bought as a whole. That would explain why the cards for bank A only have 1MB each, the max Bank A can take no matter what apparently.

 

[TheWhiteFalcon]

I like the II/IIx/IIfx line. They're serious computers for serious people.

 

[Bunsen]

Four are maxed out. Four are barely populated

Your mission, should you choose to accept it ... 

 

[unity]

^ LOL

I know, I know. I thought of it. I think they are just run of the mill chipsets. In fact even these are a mixed bag if you look at em.

 

[Elfen]

The chips are by Samsung, and are 1megs each (411000s are 1 meg chips 10ns is 100 nanosecond speed).

Since they came out of  IIx, any Mac with the 30 pin simm can use them.

 

[unity]

Thank you captain obvious.