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| Maximizing memory on my Centris 650 - will this work? | |
| Posted by: Phipli on 2023-02-11 23:29:56 @1200XL M.U.L.E. I believe EDO and Parity RAM will work too, but some macs only work with FPM, so it is handy to have incase you get another mac. Plus I'd rather recommend as close to what I have and know works. | |
| Posted by: 1200XL M.U.L.E. on 2023-02-12 14:20:44 Here's a link to the same item in USD. 
256MB (128MB x 2) 72 Pin FPM Memory SIMM 5V 60ns | eBay512MB HP 9000 Genuine A3737A A3737-60001 256MB x 2 SIMM. Condition New,Tested, 100% working condition. Helpful Links.
www.ebay.com
So, if I install these modules one by one in my Centris 650, then I should see my available memory grow by 64MB each time. Free returns too. I can disco with that. | |
Posted by: Phipli on 2023-02-12 14:24:46So, if I install these modules one by one in my Centris 650, then I should see my available memory grow by 64MB each time.Yes. Also the machine supports interleaving, so having memory installed in like pairs gives a small number of percent speed improvement. | |
| Posted by: 1200XL M.U.L.E. on 2023-02-16 16:21:49 My four sticks of memory arrived today. I installed them one by one and watched my total available memory climb by 64MB with each stick added. My machine now has a whopping 256MB of RAM. I could not imagine this number on any machine in 1994. I think my 486 system back in the day used to have 8MB and then 16MB and I felt like a god with that much RAM.  Now I understand the longer boot time. My Centris just sits there after the chime, not displaying anything. This must be the memory test. After the memory test is over, the monitor comes to life and slowly warms up. Then I see the welcome screen and the extensions start loading. At first this freaked me out. Seeing nothing is scary! I'm not sure what I'll do with 256MB of RAM 😄 but I'll have it ready when I need it. | |
Posted by: Phipli on 2023-02-16 16:27:34My four sticks of memory arrived today. I installed them one by one and watched my total available memory climb by 64MB with each stick added. My machine now has a whopping 256MB of RAM. I could not imagine this number on any machine in 1994. I think my 486 system back in the day used to have 8MB and then 16MB and I felt like a god with that much RAM.Glad everything worked out 🙂 Does your 650 board have the ROM slot fitted, or is the location unpopulated? | |
Posted by: Phipli on 2023-02-16 16:31:07 | |
| Posted by: 1200XL M.U.L.E. on 2023-02-16 16:32:12 My board looks just like your picture. There is nothing there. What was the ROM slot for, if it were to be installed? | |
Posted by: Phipli on 2023-02-16 16:37:39My board looks just like your picture. There is nothing there. What was the ROM slot for, if it were to be installed?Apple tended to include a ROM SIMM slot on early machines of a model (or all of them on older machines). It meant if they messed up they could send out physical ROM updates. A ROM SIMM fitted there overrides the onboard one. You can modify the stock ROM, put it on a SIMM... and install it. One such mod is to disable the RAM test... Another is to make it recognise 128MB SIMMs! I believe it gets upset if you install more than 128+128+64+32+8... 360MB if I remember. This might... be a project for the future. Soldering in slots and making custom ROMs is probably for the second month of Mac ownership 😆 | |
| Posted by: Phipli on 2023-02-16 16:42:11 Background reading : For reference, the 610 has the same ROM, but only two RAM Slots. | |
| Posted by: 1200XL M.U.L.E. on 2023-02-16 16:51:57 Oh, wow! That is pretty cool! Thanks for sharing the background on the ROM slot. 🙂 | |
Posted by: Phipli on 2023-02-16 16:54:03Oh, wow! That is pretty cool! Thanks for sharing the background on the ROM slot. 🙂Some more info here 🙂 | |
Posted by: Phipli on 2023-02-16 16:55:58I'm not sure what I'll do with 256MB of RAM264 😉 Don't forget the logic board RAM. | |
Posted by: 1200XL M.U.L.E. on 2023-02-16 17:06:46264 😉 Oh, yes. You're right. What's 8 MB between friends at this point? 😉 | |
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