Trent© said:
That was never my experience...and I built a lot of them. It was my
experience that, if you added any memory besides the on-board memory,
they had to be in 4's...on 30-pin. But I could be wrong...its been a
long time.
They were all like that back then.
No they weren't, the 486DX/2 66 that I bought had a HS and fan fitted by the
manufacturer. Slower 486 CPUs I've seen had a passive HS.
Did you ever build any 286 systems?...or 386?
No. But I played with a few.
That was not my experience...especially with the 286's.
"SIMM (Single Inline Memory Modules) were first made in 8 bit
editions. They were small cards with 1, 2 or 4 MB RAM. They were connected
to the motherboard with a 30 pin edge connector. The modules were 8 bit
wide. This meant that 16 bit processors (286 and 386SX) needed 2 SIMMs in a
pair. Thus, there was room for two modules in what is called a bank.
32 bit processors (386DX and 486) need 4 of the small 8 bit SIMMs in a bank,
since their banks are 32 bit wide. So, on a typical 1st generation 486
motherboard, you could install 4 X 1 MB, 4 X 2 MB, or 4 X 4 MB in each bank.
If you only had one bank (with room for 4 modules), it was expensive to
increase the RAM, because you had to discard the old modules."
From:
http://www.karbosguide.com/hardware/module2e2.htm
Generally? I think that's why at least *I* should move on. lol
Every 286 system that I ever built required 4 30-pin add-on modules.
"SIMMs are organized on the motherboard into sets called "banks". Older PCs,
like 286s and 386SXs, use a bank size of two, meaning SIMMs are installed in
multiples of two."
From:
http://www.daileyint.com/hmdpc/upgrade1.htm
The modules BY THEMSELVES had nothing to do with it. It was a
combination of the modules you used...and the motherboard that you put
them on.
Some double-sided modules would work with some boards...and would not
work with others.
But all this was only with 72-pin modules. They never made 30-pin
double sided...unless some guy did it in his basement.
Well, I can't find proof of the fact that I actually held a 30 pin
double-sided module in my hands that was made by Misubishi, not some guy in
his basement. However, going by the inaccuracy of your other statements that
doesn't bother me much. At the time I couldn't find a mention of the module
on the web either and I had the numbers off the PCB to search with.
Here we go AGAIN! lol I never ran across this.
Then you ran too fast.
"As a general rule, when adding memory to a 32-bit computer (386DX, 486SX or
DX, 586), you must add 30 pin SIMMs in matching sets of 4 or with 72 pin
SIMMs, one at a time. A 64-bit computer (Pentium and 686) needs 72 pin SIMMs
added in matching sets of two."
From:
http://www.icd.com/ram/
Or: "The SIMMs are on a chip with either a 30-pin socket or a 72-pin socket.
The 30 pin varieties were usually relegated to the 8086, 286, 386, and 486
family. The 72 pin sockets went into the 486, Pentium, and some Pentium II
boards. Each 30-pin chip represents 8 bits. Therefore, the 386's, being 16
bit boards, needed the SIMMs placed in pairs of 2. 486's, being 32 bit
boards, need SIMMs placed in groups of 4. The large number of 30 pin SIMMs
needed to fill one bank on a motherboard led to the development of the 72
pin SIMMs. These chips were 32 bit, and could be put 1 at a time into the
486s, and in pairs of 2 into the 64 bit Pentium motherboards."
From:
http://www.scrounge.org/ram.htm
Have you ever built a system that used only 1 72-pin SIMM? I can
honestly say that I haven't.
Hell yes! Several in fact, all 486 systems. I have one right here, right
now, that runs fine with one 72 pin module. Acer mobo.
I could spend a lot longer on this but I think it's you who needs to do the
research for yourself. It seems you can no longer rely on your memory.
