Motherboard only sees 16000KB of RAM

[Pentium100]

I have a old computer. Its motherboard is MB-8500TVD-A. It supports both SIMM and DIMM RAM. Currently there are 4 SIMM modules (I do not know their capacity) installed. Motherboard reports that is is 16000KB of RAM. If I remove two modules, the number stays the same. If I remove all SIMM modules and install 64MB PC100 DIMM module, the motherboard still reports 16000KB. How can I solve this problem?

[saphalline]

What chipset is this mobo using? I don't recall a 16MB limit before, but the chipset will tell me more.

[sia]

Hi saphalline

Exactly 16000KB is strange.

[kiosk]

This is more than likely a chipset limitation. For example, my old Abit PT5 motherboard running P1-200MMX has a limit of 16 megabytes per bank (two 72pin SIMM sockets make up for one memory bank). With two banks, i.e. four sockets, the limitation for the mobo is exactly 32 MB, which is how much I have installed in there.

I think that your second memory bank is populated by two unmached, or simply incompatible SIMMS - chipset ignores them and works only with what it can find in bank 0 - 16 megabytes.

This is a chipset limitation, not a bios one. The chipset simply doesn't know how to "talk" to higher-density memory chips and addresses what it can.

And yes, 16 megabytes (8 per stick) was a LOT of memory back in the day when EDO ram and windows 95 reigned supreme. ;)

[sia]

16MB is not 16000KB.

[saphalline]

16MB = 16384KB. But I can easily see the first 384KB being eaten by the system for shadowing or whatnot. 16000KB being exactly reported is believeable, as I've seen similar reports on older systems like that.

Hmmm... that reminds me of the 286 processor with 30-pin SIMMs that I've seen recently. Amazing little piece of computer history. I think the SIMMs were 1MB in size. Quite a lot of RAM per stick back then. I imagine 1MB 30-pin SIMM sticks once went for well over $300! :eek: Simply amazing...

[mjc]

I once had a problem with a machine that was doing something similar...I can't remember if it needed FastPage and all I had was EDO or the other way around or if the sticks were somehow mixed up...but after I acquired enough of all the same type (know to be the same and matched) it all worked out.

And I have quite a collection of 30 pin SIMMs...if they were still what they were worth all those years ago, I'd be quite well off.

[saphalline]

Yeah, I'm still working on a time machine so I can sell all my old hardware. Hasn't happened yet...