I grew up in the era where SIMMs were rapidly disappearing and DIMMs were becoming cheaper by the day. Considering I didn't do computer repair at the age of 2 or 3 (though I did learn how to configure my soundblaster! :D) I don't have much experience with SIMMs.
My method thus far has been to haphazardly put SIMMs into a machine, and if it shows an error or refuses to POST, swap the latest added SIMM (yes I know this should be dangerous, but so far nothing has ever fried or died..). This has worked splendidly for all pre-EDO/Parity/etc. boxes like 386s, and for all post-EDO/Parity/etc. boxes like early Pentiums. However, the 486 72-pin machines are a pain. I had 24MB of RAM in my ValuePoint. During my ZIP drive adventures I ended up reducing it to 16MB and am not even sure it was properly seeing the 24MB to begin with. Anywho, I have become aware that it should support up to 64MB, and in the spirit of maxing out this machine, looked through my gigantic bin of RAM (yes, I have a bin of RAM... :D) and tried many sticks. After a long period of "fun" trial and error, I decided to look at the 16MB that has been working so well. It's 70ns Parity RAM, 8MB stick * 2. I looked through my collection, noting that most were unlabeled. I tried many more sticks to no avail. I found a 70ns 4MB stick, and so tried to pair it with various other 4MB sticks in the hope that one of them would be a 70ns parity stick - no such luck. I found an 80ns 4MB parity stick, but it will not work properly in the machine (not sure why, the chip configuration or the speed is unhappy with the other stick I guess). I learned online how to identify parity sticks roughly by counting the chips, and tried any logical sticks.. no luck..
While this is not my model, this motherboard looks most similar to mine (still different) out of the ValuePoints on stason: http://stason.org/TULARC/pc/motherboards/I/IBM-CORPORATION-486-PS-VALUEPOINT-6387-T-TYPE-1.html
It has a chart for RAM which I ripped from the page to post here:
According to this I have two choices to attain 64MB: 4x4Mx36 sticks, or 2x8Mx36 sticks. Now, I was under the impression that a stick marked 4Mx36 was a 4MB stick and that a stick marked 8Mx36 was an 8MB stick, and that typically a SIMM was marked something along the lines of "4MB 2x36", not like in the table above. I ask for help in understanding this table and selecting a variety/source of some RAM for my quest here.
Thanks!
Edit: Also, could someone explain why it restricts you to certain combinations that include blank banks? That doesn't make much sense to me, I understand you need to pair and match varieties of SIMM, but why leave blank banks? Why can I not put 4x8Mx36 and get 128MB [maybe the BIOS doesn't support that much RAM, is there another reason?]?
My method thus far has been to haphazardly put SIMMs into a machine, and if it shows an error or refuses to POST, swap the latest added SIMM (yes I know this should be dangerous, but so far nothing has ever fried or died..). This has worked splendidly for all pre-EDO/Parity/etc. boxes like 386s, and for all post-EDO/Parity/etc. boxes like early Pentiums. However, the 486 72-pin machines are a pain. I had 24MB of RAM in my ValuePoint. During my ZIP drive adventures I ended up reducing it to 16MB and am not even sure it was properly seeing the 24MB to begin with. Anywho, I have become aware that it should support up to 64MB, and in the spirit of maxing out this machine, looked through my gigantic bin of RAM (yes, I have a bin of RAM... :D) and tried many sticks. After a long period of "fun" trial and error, I decided to look at the 16MB that has been working so well. It's 70ns Parity RAM, 8MB stick * 2. I looked through my collection, noting that most were unlabeled. I tried many more sticks to no avail. I found a 70ns 4MB stick, and so tried to pair it with various other 4MB sticks in the hope that one of them would be a 70ns parity stick - no such luck. I found an 80ns 4MB parity stick, but it will not work properly in the machine (not sure why, the chip configuration or the speed is unhappy with the other stick I guess). I learned online how to identify parity sticks roughly by counting the chips, and tried any logical sticks.. no luck..
While this is not my model, this motherboard looks most similar to mine (still different) out of the ValuePoints on stason: http://stason.org/TULARC/pc/motherboards/I/IBM-CORPORATION-486-PS-VALUEPOINT-6387-T-TYPE-1.html
It has a chart for RAM which I ripped from the page to post here:
Size Bank 0 Bank 1 Bank 2 Bank 3
16MB (1) 2M x 36 (1) 2M x 36 NONE NONE
32MB (1) 2M x 36 (1) 2M x 36 (1) 2M x 36 (1) 2M x 36
32MB (1) 4M x 36 (1) 4M x 36 NONE NONE
64MB (1) 4M x 36 (1) 4M x 36 (1) 4M x 36 (1) 4M x 36
64MB (1) 8M x 36 (1) 8M x 36 NONE NONE
According to this I have two choices to attain 64MB: 4x4Mx36 sticks, or 2x8Mx36 sticks. Now, I was under the impression that a stick marked 4Mx36 was a 4MB stick and that a stick marked 8Mx36 was an 8MB stick, and that typically a SIMM was marked something along the lines of "4MB 2x36", not like in the table above. I ask for help in understanding this table and selecting a variety/source of some RAM for my quest here.
Thanks!
Edit: Also, could someone explain why it restricts you to certain combinations that include blank banks? That doesn't make much sense to me, I understand you need to pair and match varieties of SIMM, but why leave blank banks? Why can I not put 4x8Mx36 and get 128MB [maybe the BIOS doesn't support that much RAM, is there another reason?]?
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