Well i have myself a bit of trouble with some ram for an old 486 of mine i just got for free
Its a Pine PT-429 mobo with a Cyrix Cx486 DX2/66 cpu with 4 30 pin simm slots and 2 72 pin simm slots which i have enough sticks of ram to fill them all

First i put em all in and boot up and it show that i have only 8mb of ram total which i know is wrong so then i try mixing around the ram and each combo i can think of lands me with 8mb except the odd combo i tried that lands me with only 4mb

I then went and got some pdf files on my mobo from pine's support website and started playing around with the jumpers setting up the 72 pin simms to be bank 0 and 1 while the 30 pins are bank 2
The documentation also tells me that 4 30 pin simms = 1 bank and 1 72 pin simm = 1 bank and that i cant have partial banks only full ones

After i got the jumpers all setup to what i could tell to be correct i then popped all the sticks of ram back in place and what do i get but 12mb of ram which i still think is wrong since each stick of 72 i have is labeled to be 8mb sticks
So now i decided to just have the 72 pin simms in with no 30 pin simms and i get that 8mb of ram only showing for me yet again

I am pretty much at the end of what i can think of doing to solve this problem and am wondering if anyone here may have a clue as to how i may solve this ever so anoying problem that doesnt seem to end for me

Oh and as to the size of the 30 pin simms i have i am not too sure as to what the sizes of them are, all i know is that each one has 3 chips on em and 3 of the 4 sticks are stamped with GoldStar and the other is stamped as TOSHIBA

Any help is appreciated since im completely lost now and am not too great with 486's since i only had one ages ago for a short while till i got my P2

You can only use ONE type of memory on this board.

HTH

A friend of mine at work also told me that its not possible to mix the 2 types of ram and like i have said somewhere in the middle of my inital post in this thread i tried with just the 72 pin simms in and got 8mb showing for me which i see to be wrong since each 72 pin i have is a 8mb stick so it should be 16mb instead of the 8mb it tells me i have

Are both 72 pins the same ?
Because they can vary on speed a lot, and your board also has to support the speed of the memory, if I recall correctly, the 72p can range from 60ns to 120ns, and some boards can only take certain type depend on the BIOS and what CPU you have.

HTH

Well the 2 sticks of 72 pins i have are both the same, they have and IBM label and the chips on the stick have a symbol that looks just like the Mitsubishi logo on them and the label on the back of both ram both say
'8MB 60NS (2Mx32) 5V H N'

The bois that is on my Pine PT-429 mobo is the AMIBIOS (American Megatrends) and the only documentation that i can seem to find on the mobo for this 486'r of mine is the 2 pdf files that i got from the pine support website which both the pdf files are the exact same file, just 2 different file names

Also from what i can see in those pdf file there dont seem to be any specs on the speed of the ram supported and stuff like that, just seems to be nothing more than a whack of jumper settings and some specs on other stuff

Jack, try swapping the 72pins around, and see if you still get only 8MB showing, I guess there may only be 2 answers, either 1 of the memory is bad, or one of the memory socket is.

Well this time around i put the 72's in and got 8mb then i switched them around and got 8mb again after which i then only put 1 72 in and got 4mb then i put the other 72 in on its own and got 4mb and then i tried them both on there own again but in the other slot and got 4mb yet again

Now the only thing that i can come to think of is that the sticks of 72 that i have somehow are mislabeled and are actually 4mb sticks, other than that i have now idea as to what the reason behind this all may be :confused:
I just dont understand why they would be mislabeled though, oh well, i got it all for free so i got more than expected i guess, at least i can still run i lil linux box off it :D