68kMLA Classic Interface
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| Romin-ator II woes in a Macintosh IIfx | |
| I have tried just about everything I can think of the get a Romin-ator II to fit securely in my Macintosh IIfx. I have tried everything from rubber bands to shims to no avail. The Romin-ator II eventually comes loose and I have to push it back into place again. I finally gave up and went back to the original ROM SIMM and have had no issues since. Is there a ROM SIMM replacement that would fit better? Posted by: jasa1063 on 2025-06-28 20:22:21 | |
| Some of the custom ROM SIMMs use thinner PCBs and therefore don't fit correctly into the slots. However, I've never had one come loose. Is your problem caused by the metal latches not firmly gripping the SIMM? Posted by: ObeyDaleks on 2025-06-28 21:02:21 | |
Some of the custom ROM SIMMs use thinner PCBs and therefore don't fit correctly into the slots. However, I've never had one come loose. Is your problem caused by the metal latches not firmly gripping the SIMM?It seemed pretty secure when I checked that. I just think the thinner PCB is most likely the issue. I may try thickening the metal contacts with some solder. Posted by: jasa1063 on 2025-06-29 13:30:31 | |
I may try thickening the metal contacts with some solderI'll bet the lead-free solder works well for this, let us know how this turns out. Posted by: Juror22 on 2025-06-29 13:53:44 | |
I'll bet the lead-free solder works well for this, let us know how this turns out.I don't know if I am going to try this or not. It's working fine with the original ROM SIMM. I leaning towards just leaving it the way it is. Posted by: jasa1063 on 2025-06-29 14:57:02 | |
| I would have expected the IIfx rom socket to be fine with modern roms that are thinner. I haven’t had an issue. I am using the CayMac universal rom and I believe it’s thinner than stock just like the rominator. I had an issue with pcb thickness on my SE/30 for which I replaced the rom socket. That’s a better fix than trying to modify the rom itself. But that’s problem I thought only really impacted sockets with plastic clips. Posted by: jmacz on 2025-06-29 17:34:20 | |
| There's nothing magic about the metal clip sockets. I have an SE/30 that simply will not work reliably with a BMOW Rom SIMM, even after bending the clips in a bit. That helped, but it still crashed intermittently. I tried building up the contacts with solder. Again it helped a bit but not enough. I went back to my original Downtown Doug Brown 2MB SIMM and it's solid again. Doug used a thicker PCB stock that's apparently not common anymore. Recently I picked up a couple of shims from CayMac and will give those a try the next time the machine is apart. Posted by: shirsch on 2025-06-29 19:12:52 | |
| New rom sockets I picked up from PE under recommendation from @zigzagjoe made an immediate difference on my two SE/30 boards. Same modern ROMs wouldn’t work on the stock plastic clip sockets. The new sockets worked for the stock ROMs too. My guess was the plastic clips slightly deformed over time. But that’s just my experience. And again, had no issues with the stock metal clipped ones on my IIfx and IIci’s. Posted by: jmacz on 2025-06-29 19:19:23 | |
| Absolutely. Something just plain gets out of tolerance. In my case the socket looks slightly bowed in the horizontal plain. The DDB SIMM is rigid enough to pull it into alignment. The BMOW SIMM flexes with it. Posted by: shirsch on 2025-06-29 19:23:27 | |
My IIci's socket with metal clips has gotten really loose because of all the testing I did of the SIMMs when I was selling them, so they too can go bad. In my case it's probably just from constantly inserting/removing. I believe the parts are rated for only so many insertions.I went back to my original Downtown Doug Brown 2MB SIMM and it's solid again. Doug used a thicker PCB stock that's apparently not common anymore. Yep, and it was purely by accident, haha! When I first did the project with the 2 MB SIMMs, it was the first time I ever designed a PCB. I ordered the boards from Seeed Studio and they were more like 1.3mm instead of 1.2mm, even though I specifically ordered 1.2mm because it was the closest they had. Heck, I don't think I even knew the correct thickness was 1.27mm at that time. I thought it was odd they were thicker than I asked for, but they fit snugly in the sockets just fine and I was happy. I had no idea what was about to come after that point with everything being too thin. I wonder if they were still making them as 1.27mm at that time, or if I got lucky with tolerances, or what. Then, when I designed and ordered the 8 MB version, and other stuff like the IIfx RAM, those PCBs were actually 1.2mm. I didn't notice any problems with my testing, but a bunch of SE/30 users ran into issues. Adding solder to the SIMM contacts can help, but it's difficult to add a thin layer evenly, and I would guess that if you make it too thick it'll damage your socket. Every time I've tried to order 1.2mm PCBs since then, I have never been able to hit the jackpot like I originally did. They're always right around 1.2mm. I believe BMOW eventually found a vendor that can do a special process to make them slightly thicker, so his more modern SIMMs are better. Posted by: dougg3 on 2025-06-29 19:27:26 | |
| I think the real answer is a standard PCB size (i.e. too small for proper fit in the vintage sockets) with a shim soldered to one side. Posted by: shirsch on 2025-06-29 19:44:23 | |
I would have expected the IIfx rom socket to be fine with modern roms that are thinner.My experience has been the opposite. My IIfx struggled with the stock ROM because of a weak ROM socket. I don't know if I am going to try this or not. It's working fine with the original ROM SIMM. I leaning towards just leaving it the way it is.Yes, this is what I would recommend too. Custom ROMs are overrated and not as useful as people think. Posted by: joshc on 2025-06-30 00:51:42 | |
Custom ROMs are overrated and not as useful as people think. The only value I get is disabling the memory check. Too impatient when you have 32mb+ installed 🙂 Posted by: jmacz on 2025-06-30 01:06:50 | |
There is now finally a solution for ROM SIMMs such as the ROM-inator II that are too thin to fit snugly in a ROM SIMM socket. A ROMSHIMM from Jurassic Computing on Tindie. I got one of these and it works great in my IIfx with a ROM-inator II. It should work in a SE/30 too!
1pcs ROMSHIMM interposers: fix poor contact issues by Jurassic Computing on Tindie1pcs ROMSHIMM interposers: fix poor contact issues in ROM SIMM sockets
www.tindie.com
Posted by: jasa1063 on 2025-11-22 15:19:50 | |
| I'll second the suggestion for the ROMSHIMMs. Fixed a bunch of annoying problems on one of my SE/30's. Not shipping to the USA at the moment because we're too busy winning. Posted by: shirsch on 2025-11-22 18:44:36 | |
I'll second the suggestion for the ROMSHIMMs. Fixed a bunch of annoying problems on one of my SE/30's. Not shipping to the USA at the moment because we're too busy winning.There is shipping to the US right now, but only expedited shipping is available. Posted by: jasa1063 on 2025-11-22 18:54:30 | |
Not shipping to the USA at the moment because we're too busy winning.Having a Charlie Sheen 'winning' flashback! 🙂 Posted by: Juror22 on 2025-11-22 19:00:34 | |
Having a Charlie Sheen 'winning' flashback! 🙂 Hahaha, yeah, love the reference 😂 Posted by: nathall on 2025-11-22 19:54:00 | |
Not shipping to the USA at the moment because we're too busy winning.Almost spit up my Diet Coke reading this comment @shirsch!!! But seriously though, there are several things I am waiting to buy from Jurassic Computing. Now I need to add this shim to my list. Posted by: frontein1 on 2025-11-22 20:45:24 | |
| I just got done installing a ROMSHIMM in both of SE/30s and again these make all the difference. The creative people in the Retro computing community never cease to amaze me. Just one more thing that makes this hobby so much fun and rewarding! Posted by: jasa1063 on 2025-11-24 22:55:20 |