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New production of STE 30pin simms.

Posted: Thu May 18, 2017 6:01 pm
by exxos
I personally have got tired of hunting around for 30pinn simms for the STE. So I designed my own.

18222519_10209514575796949_6645816888172709426_n.jpg


I designed these for myself mostly, though if there is interest I will build some batches up. Price would be around £25-£30 a set at a guess.

My prototypes are currently on their way to me. So hope to test them out soon.

Re: New production of STE 30pin simms.

Posted: Fri May 19, 2017 8:09 am
by alienkidmj12
Nice, Dave sives here. That would be awesome ;)

Re: New production of STE 30pin simms.

Posted: Fri May 19, 2017 8:26 am
by exxos
alienkidmj12 wrote:Nice, Dave sives here. That would be awesome ;)


Question solved then ;)

Re: New production of STE 30pin simms.

Posted: Fri May 19, 2017 9:18 am
by spiny
that's really cool :)

I'd buy a set :)

Re: New production of STE 30pin simms.

Posted: Fri May 19, 2017 9:42 am
by dhedberg
I don't have an immediate need but would any of the SIMM modules in my Atari computers ever go bad I would prefer buying new ones instead of used ones.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 10:29 am
by exxos
*drools*
exxos_simm.jpg

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 11:13 am
by dhedberg
exxos wrote:*drools*
exxos_simm.jpg

Nice! Where do you have your PCBs manufactured?

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 11:35 am
by exxos
dhedberg wrote:
exxos wrote:*drools*
exxos_simm.jpg

Nice! Where do you have your PCBs manufactured?


Prototypes I used oshpark.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 11:48 am
by exxos
Time for testing :)


simm30.jpg


simm301.jpg


Yay I have 4MB purple simms, mission accomplished [smilie=greencolorz4_pdt_01.gif]

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 12:58 pm
by Badwolf
I have no immediate need for any myself, but I'm pretty sure if I had, making my own SIMMs would never had occurred to me.

I just wanted to tip my hat and say what a simple and sensible solution, especially if they can become an item in your shop or a made-to-order offering. Top work. :-)

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 1:09 pm
by exxos
Badwolf wrote:I have no immediate need for any myself, but I'm pretty sure if I had, making my own SIMMs would never had occurred to me.

I just wanted to tip my hat and say what a simple and sensible solution, especially if they can become an item in your shop or a made-to-order offering. Top work. :-)


Simms are getting harder to find. Most people just get them on evilbay. Though they are getting harder and harder to find and mostly used simms, prices are only going to go up and get harder to find. So now there is a solution for the future. This does depend on availability of the DRAM, I have found a few sources for them, so currently "easy" to obtain.

I never intended to produce this , at least not short term. If there is enough demand I will build up some sets for my store. Though generally simms don't sell well in my shop as people shop around for the cheapest ones mostly.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 1:16 pm
by EmpireAndrew
While I don't have a problem finding 30 pin simms at the moment, prices for a set of 4 x 1MB ones seem to go for between 12 and 22 dollars on evilbay and there's more than a hundred ads for 1MB simms on there. So right now, this isn't necessary for me.

But...

Going forward this kind of thing is hugely important.

I've even considered buying dead Atari's and other machines if I can get them dirt cheap enough, just to salvage the custom IC's and boards for the long term... Sadly asking prices for dead stuff is just way to high at the moment to justify that.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 1:41 pm
by exxos
A lot of them are FPM simms, I tried a bunch of them a while ago and they didn't work. Also parity simms which are not great. If you rule out those, you would be pushed to find them in EU. USA seem to always have good stuff.. but not so easy over here.

In anycase, I never intended these as a production run, I just wanted purple simms :) Plus the design is done should the time come that people want them.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 2:15 pm
by Kubik
Did you see any problems designing and testing those? I am basically about to do the same, but for 4MB SIMMs (for old MACs, SoundBlasters etc), and I wonder if there's something I should be aware of.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 2:18 pm
by exxos
Had no problems doing these. Largest problem was finding the DRAM ICs.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 2:37 pm
by AdamK
Could you do 16MB simms?

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 2:40 pm
by exxos
AdamK wrote:Could you do 16MB simms?


Possible yes. Only factor is finding the DRAM for them.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 3:27 pm
by dhedberg
exxos wrote:Had no problems doing these. Largest problem was finding the DRAM ICs.

May I ask what your source for the DRAM is? I understand if you don't want to reveal it... just thought it would be worth asking at least.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 3:33 pm
by exxos
dhedberg wrote:
exxos wrote:Had no problems doing these. Largest problem was finding the DRAM ICs.

May I ask what your source for the DRAM is? I understand if you don't want to reveal it... just thought it would be worth asking at least.


For this particular DRAM chip
http://www.jotrin.com/product/parts/HY514400AJ_70

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 3:46 pm
by dhedberg

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 3:48 pm
by exxos
Its a pretty common chip to find really. Its just trusting the source like always, what china print on them, isn't always what the IC is. It just took a huge amount of work to work out a part number which could actually be found.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 3:57 pm
by joska
exxos wrote:A lot of them are FPM simms, I tried a bunch of them a while ago and they didn't work.


If they did not work then it was not because they were FPM SIMMs. The majority (all?) of 30 pin SIMMs are FPM and works perfectly fine in the STE. You probably know this, because the DRAMs used in your own SIMMs are also FPM :)

exxos wrote:Also parity simms which are not great.


There is nothing wrong with parity SIMMs. Even if the ST does not use it doesn't mean that it does any harm.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 4:05 pm
by exxos
joska wrote:If they did not work then it was not because they were FPM SIMMs. The majority (all?) of 30 pin SIMMs are FPM and works perfectly fine in the STE. You probably know this, because the DRAMs used in your own SIMMs are also FPM :)


Some sites listed them as FPM, some didn't. Same with some datasheets. So wasn't really sure either way, so thought I would just try them and see.

I know people have said FPM works, but the stack of them I have here didn't work. I just got all kinds of crazy on the screen and just gave up with them.

joska wrote:There is nothing wrong with parity SIMMs. Even if the ST does not use it doesn't mean that it does any harm.


That's not exactly correct. It depends on the DRAM. Generally speaking they don't do any harm, *if* the logic floats high and is stable, but its not always the case. Generally parity chips should be avoided, or the parity chip taken off, which is what I have been doing.

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 4:19 pm
by spiny
I (clearly) know very little about such things, but would modern 'faster' chips help with the other upgrades, like the boosters and TOS replacements? or is RAM just not a bottleneck?

Re: New production of STE 30pin simms.

Posted: Tue May 23, 2017 4:32 pm
by exxos
spiny wrote:I (clearly) know very little about such things, but would modern 'faster' chips help with the other upgrades, like the boosters and TOS replacements? or is RAM just not a bottleneck?


Problem is, DRAM speed isn't the issue, its the MMU speed is fixed. So 500ns DRAM or 50ns DRAM, the controller still runs at the same speed. The DRAM speed is just the speed it can run at, not the speed it actually runs at.

I developed my RAM kits based on faster DRAM chips with the intention to speeding up the ST-RAM (as mentioned in other posts this week).