Advice on Mac SE/30 RAM

[billbucks]

Hi,
After recapping the board, I have a functional Mac SE/30 with Mac OS 7.5.3 + 5 MB RAM (probably 4 * 1MB + 4 * 256kB) + BlueSCSI v2.
I'm looking at options to expand the RAM using Connectix Mode32.
Does it work without a Rominator ?
I read it would let me support up to 128MB. What's the actual purpose of this amount of RAM compared with the max supported RAM for the non modified Mac SE/30 which seems to be 8MB ?
Would it work if I start with 1 or 2 x 16MB 30pin SIMM after installed Mode 32 ?

Note that I plan to test and use the Wifi features of BlueSCSI v2.

 

[Garrett]

You don’t need an aftermarket ROM if you’re using mode 32. Another thing- RAM must be installed in sets of four (see attachment). I personally have never installed more than 20MB in an SE/30, but can see the appeal of doing more from a “wow” standpoint. Eight 4MB modules would be a good balance of cost, boot up time, and usability if that’s what you’re after!

 

[billbucks]

Thanks for the advice.
I found these on eBay: RAM SIMM 4 * 4MB
If I keep the 4 x 1MB and add these 4 SIMMS, I'll get 20 MB.

Will it work and do I need Mode32 installed ?

 

[pfuentes69]

Thanks for the advice.
I found these on eBay: RAM SIMM 4 * 4MB
If I keep the 4 x 1MB and add these 4 SIMMS, I'll get 20 MB.

Will it work and do I need Mode32 installed ?

If you go over 8MB of RAM you'd need Mode32 or an alternative ROM

 

[reasonsandreasons]

Duty-bound to share that OWC still has new 16MB 30-pin SIMMs in stock. A set of four will take you to 64MB for $45 USD.

 

[croissantking]

Duty-bound to share that OWC still has new 16MB 30-pin SIMMs in stock. A set of four will take you to 64MB for $45 USD.

I bought a set of four and I found they don’t properly fit the SE/30 chassis.

 

[reasonsandreasons]

Try putting them in the bank that’s closest to the front of the chassis—they fit in that one on mine but not the other.

 

[speakers]

I bought a set of four and I found they don’t properly fit the SE/30 chassis.

Strange. I very recently installed 4 x 16MB of the OWC SIMMs in my SE/30 without issue. And I also use these in cx, ci and q700.

In what way don't they fit?

 

[croissantking]

Strange. I very recently installed 4 x 16MB of the OWC SIMMs in my SE/30 without issue. And I also use these in cx, ci and q700.

In what way don't they fit?

Well, they are quite tall and the chassis doesn’t have enough clearance. They fit in one bank but not the other.

 

[speakers]

Well, they are quite tall and the chassis doesn’t have enough clearance. They fit in one bank but not the other.

There must be some variability though I've not not seen any. If you're not satisfied, get in touch with them since I know they have good customer support and returns.

 

[croissantking]

There must be some variability though I've not not seen any. If you're not satisfied, get in touch with them since I know they have good customer support and returns.

I’ve just put those modules in my IIci so no problem.

 

[billbucks]

I bought new purple 4 * 4MB RAM which work well on my Mac SE 30.
I found an interesting article to install Mac OS 8 on a Mac SE 30 from MetalBabble blog. However the links to download the os8 patch no longer works.
Has anyone try it and has a copy of the required files, especially the patch ?

 

[croissantking]

Yes OS 8 on an SE/30, wildly inappropriate.

There‘s a working download link to the patch on this page:

Vintage Apple - Gamba - >Installing OS 8 & OS 8.1 on 68030 Macs

 

[billbucks]

Thanks for the link, I managed to download the patch.
What are the risks of running OS8 on an SE/30 ? Performance issues, crashes even with 20, 32 or more RAM ?
I will give it a go as it sounds fun, yet hoping it could be a stable replacement of 7.5 to use the Mac.

 

[croissantking]

No risks, it works fine. Just a bit slow on the stock 16MHz 030. I prefer to run 7.5.5 but I do have an install of 8.1 because as you say, it is a curiosity to use on a compact Mac.

 

[Peter-Erik]

Hi All,

PurpleRAM 64MB (16MB x 4) 30-pin DRAM SIMM kit by Jurassic Computing on Tindie

PurpleRAM 64MB (16MB x 4) 30-pin non-parity DRAM SIMM kit

www.tindie.com

Any idea of these works in an SE/30? (using Connectix Mode32.)

thanks

 

[JDW]

Any idea of these works in an SE/30? (using Connectix Mode32.)

Yes because if you look closely at all the photos, you will see one is of that RAM installed into an SE/30 motherboard. I have purchased RAM from him before and it works great. Not sure why, but he seems one of the only RAM sellers who chooses to use gold plating, which I really like. The only caveat would seem to be shipping to the US (if that applies to you), as the only method offered is "expedited" which I assume means "more expensive." But the base cost of his RAM is extremely competitive.

 

[YMK]

Not sure why, but he seems one of the only RAM sellers who chooses to use gold plating, which I really like.

Probably because it's not a good idea with tin sockets:

https://www.ramoem.com/uploads/4/4/0/7/44075859/gold_rules.pdf

I read something similar in an Apple document, but I can't remember which one at the moment.

 

[JDW]

@YMK
Oh, I did not know that. Very interesting. It makes you really think more deeply about gold contacts.

But of course, many commercial connectors have long mated gold-plated pins to tin-plated sockets, and those devices have worked as expected for decades. I suspect there are many factors at play here, such as how thick the gold plating is, the insertion force and scraping, vibration and temperature, electric current passed through the connections, etc. It's not clear how much the scraping of the gold comes into play because gold is a very soft metal.

Gold-to-gold might be better in theory, but when you repeatedly insert and remove, that scraping can wear off the gold in spots over time.

I guess it boils down to practical experience though. How many devices have failed due to gold-on-tin contacts? And can we argued from an informed position that gold contacts on RAM SIMMs would be inferior in actual practice.

Would love to read that Apple document you mention, should you ever find it. Might prove to be an interesting read.

Thanks again for bringing this to my attention. I don't think it necessarily undermines the designs created by Dr. Antoine Bercovici (SiliconInsider, creator of that purple, gold-plated RAM), but it might be nice to hear his opinions too.

 

[JDW]

Continuing my investigation, I spoke with someone moments ago who said that he estimates 10% of 30 pin modules from back in the day are gold plated and possibly 50% of 72 pin modules are gold plated. He went on to say that very few sockets are gold plated, and yet over the last 40 years, we’ve not seen catastrophic failures of gold being matched with tin.

Even from back in my engineering school days, we were taught about the surprising differences that one can find between the theoretical and the experimental. So we could chalk it up to that, especially because there are many factors that come in to play.

But I suspect that most modern vendors of RAM SIMMs are avoiding gold, not because of the discussion that we’re having now, but simply because it’s more expensive.

Of course, I’m not disagreeing with the theory and I still appreciate it very much. I always like to be informed. And I still would love to see that Apple document someday. But for now, I have vintage machines with the aforementioned RAM working well and I’m not too deeply concerned about it.