Source for RAM?

[caver01]

The retro-computing hobby, especially as it applies to compact Macs is as much about troubleshooting and repair as it is about using these systems. For many of us, the experience or journey to a successful restoration is the reward.

With that in mind, an important troubleshooting step (and part of finishing the job in every case) is to install known-good working RAM. For someone just getting started, or trying to grow their experience and inventory, I am hoping a few veterans can share sources for obtaining 30-pin SIMMs, and maybe some advice about what to avoid, or how much we might expect to pay.

As a US resident in the Pacific NW, I am looking for a good source, not super expensive. Maybe I should be looking at eBay? But is there a less-well-known seller, or some stockpile of old SIMMs I am not aware of somewhere? I am not looking to max out my SE/30 for example, but it seems prudent for me to have a good supply of 1mb SIMMs to finish restoration of a handful of SEs, Classic, and spares for troubleshooting and growth. Over time, I can collect more, but can someone suggest a good starting point?

Thanks!

 

[Drake]

The retro-computing hobby, especially as it applies to compact Macs is as much about troubleshooting and repair as it is about using these systems. For many of us, the experience or journey to a successful restoration is the reward.

With that in mind, an important troubleshooting step (and part of finishing the job in every case) is to install known-good working RAM. For someone just getting started, or trying to grow their experience and inventory, I am hoping a few veterans can share sources for obtaining 30-pin SIMMs, and maybe some advice about what to avoid, or how much we might expect to pay.

As a US resident in the Pacific NW, I am looking for a good source, not super expensive. Maybe I should be looking at eBay? But is there a less-well-known seller, or some stockpile of old SIMMs I am not aware of somewhere? I am not looking to max out my SE/30 for example, but it seems prudent for me to have a good supply of 1mb SIMMs to finish restoration of a handful of SEs, Classic, and spares for troubleshooting and growth. Over time, I can collect more, but can someone suggest a good starting point?

Thanks!

Typically I just search 30 pin Edo on eBay. In regards to se/30 and other 30 pin machines that take more there are options to build and assemble your own. (If you're inclined to journey down that rabbit hole)

 

[Kai Robinson]

1MB SIMM's are now open source: https://github.com/hegars/1M-30pinsimm

Relatively easy to build your own, now!

Same github has 4MB ones listed, too. I've built both variations, they work just fine in my SE/30

The chips are available from UTSource - $1.58 per chip, you need 2 chips per simm so a cost of roughly $5 all in, once you take the PCB itself into account (assuming you're buying in volume enough to make the price per board cheap, like 50 PCB's or so)

HYB514400BJ-60 Price - HYB514400BJ-60 in stock - Buy HYB514400BJ-60 on Utsource.net

Description: 4M x 4 DRAM, 60ns Features: - 4 Meg x 4 bit organization - Fast page mode access time of 60ns - Single power supply of +5V ±10% - Fully static operation

www.utsource.net

 

[rikerjoe]

I’ve used Memory Masters via eBay for my classic Macintosh memory needs with no issues. The roll-your-own solution that @Kai Robinson mentioned is very tempting, if only there were 16 MB SIMMS available….

 

[Kai Robinson]

What, like these?

https://www.tindie.com/products/garrettswrkshp/gw4192a-4x-16-mb-30-pin-ram-simm-64-mb-kit/ by @Zane Kaminski of Garrett's Workshop

or

16MB 30pin non-Parity SIMM RAM MEMORY 60ns for Apple, macintosh, Musical sampler, old PC, Video controller

Two chips per simm, low power consumption, test working on most old Apple PC, macintosh, Musical sampler, video cards, old PCs.

keystron.com

 

[rikerjoe]

Haha, yes @Kai Robinson! I should have been clearer and said “build your own” 16MB SIMMs

 

[Kai Robinson]

*cracks whip* @Stephen @GeekyBit GET TO WORK!

 

[Stephen]

*cracks whip* @Stephen @GeekyBit GET TO WORK!

I do have a 30 pin design, but so does @Zane Kaminski on the Garrett's Workshop github. Probably the most convenient (and well documented) starting point for anyone that wants to roll their own

 

[caver01]

Relatively easy to build your own, now!

Wow. Ok. Mind blown. I should not be surprised by this at all, but I am. However, this makes a lot of sense given how simple these little boards actually are. I am tempted to try this just for the sake of being able to, and with only two chips per 1MB stick, the soldering from new chips would not be that tough even by hand. Taking chips off a donor SIMM would be a bit tedious without hot air station. This would be a first for me, ordering boards from a fabricator. Any chance someone has already done that and has kits to sell?

@rikerjoe thanks for the ebay seller tip too. Depending on pricing, I might save myself the build trouble, but this is fascinating!

 

[caver01]

Follow up question: Parity vs. Non-parity. . . I am seeing Parity, 9-chip SIMMs that are cheaper than those only populated with 8. Can I use these in compact macs? Or do they have to be non-parity? And what’s with the warning I have seen written about avoiding composite RAM?

 

[Hurry]

I’ve used Memory Masters via eBay for my classic Macintosh memory needs with no issues.

Seconded. I just received an order from them for two different compact Macs, very pleased with pricing/shipping/customer service.

 

[Patrick]

Follow up question: Parity vs. Non-parity. . . I am seeing Parity, 9-chip SIMMs that are cheaper than those only populated with 8. Can I use these in compact macs? Or do they have to be non-parity? And what’s with the warning I have seen written about avoiding composite RAM?

at the risk of being wrong on the internet.

i think the parity is just ignored on macs. you can use simms that have the parity chip but it won't have the parity stuffs

 

[Kai Robinson]

at the risk of being wrong on the internet.

i think the parity is just ignored on macs. you can use simms that have the parity chip but it won't have the parity stuffs

You're actually correct, unless you have one of those rare IIci machines that had the parity chip in it, parity is ignored. On the SE, the pins aren't even connected.

 

[caver01]

Thanks for confirming. It definitely opens more options when considering different offers.

 

[polpo]

If you don't want to DIY, Keystron is another source of new SIMMs using reused & NOS memory chips similar to Memory Masters. I've had good luck with them in my Macs and they're reasonably priced. They sell on eBay but the prices in their own online store are better: https://keystron.com/collections/computer-memory/pin_30-pin

 

[pfuentes69]

I made myself these 4MB SIMMs last weekend, pretty happy with the result, but now I have to redo it because I didn’t pay attention to the PCB thickness and the default 1.6 mm of JLCPCB is too much… so if anyone gets into this project better you don’t repeat my silly mistake and ensure you select 1.2 mm.