Milan maximum RAM

[PeterS]

I currently have 144MB in the Milan which is made up of 64, 32, 32, 16.

Does anyone have a Milan with more than this ?

A few years ago I bought 4 large (128MB I think) SIMMS for the Milan, while I could still find them. I believe these are the largest ones that are supported according to the manual.

I tried them but the Milan wouldn't boot properly. I recall it would work with 1 but not 2 or something like that. I thought it was bad connections. The slots do seem sensitive and often lose memory and the cards have to be wiggled to get it back again.

Then I heard that Alan H had a similar problem and wondered if it is a problem with the Milan itself such as a voltage, current or timing problem but I have no idea about fixing such things.

[Neurotoxic]

RAM and the Milan is a mystery! I've got 48 MB RAM in my Milan using EDO PS/2 simms. My third ram socket is damaged. I don't know what happend to the socket but it's bent. When I bought the Milan from its former owner the socket was already like this. So no simm is working in that damaged socket. Last autumn I got an old Pentium MMX PC. On the motherboard of that PC were two sockets with 32 MB EDO PS/2 simms in it. So I thought I could use these simms in my Milan. I just took the two 32 MB EDO simms from the PC and one of the 16 MB simms I've already used in my Milan. But the Milan didn't boot with that combination. So I tried the two 32 MB simms only. The Milan didn't boot. Than I tried only one 32 MB RAM simm. It didn't boot! I also tried a combination of one 32 MB simm and a 16 MB simm. It just didn't work. Than I tried all of the three 16 MB EDO simms in different combinations wih the 32 MB simms. No combination worked! So I put back the three 16 MB simms in my Milan. The Milan didn't boot with these simms anymore, either!!! I thought, that was it! You destroyed the motherboard!!! But I just remembered that I bought two years ago a little box from ebay with ca. 30 PS/2 simms and a few simms in it. So I took a look at the box and just found four 16 MB simms that might fit into the Milan. I tried one of them an the milan booted again. I placed the next one into the second socket and again the Milan booted! The third simm in the forth socket (the third one is damaged) and the Milan booted. So I still have 48 MB RAM in my Milan but I just don't really know what happend? Were the other simms the destroyed by using the 32 MB simms ? Were the 32 MB RAM simms destroyed by the motherboard? Very, very strange behavior!

So if you want to replace your ram in the Milan, I recommend to remove all the simms from the Milan and just start with one f the new simms in the first socket. This simm must 16 MB or lager. Than remove it and test the next one and the next one and the next. When all simms are working correctly just try them together.

[frank.lukas]

512MB max -> http://www.uweschneider.de/Projekte_Milan.php

[joska]

The Milan can use SIMMs up to 128Mb size (*). However, not all SIMMs works. Maybe the Milan use the four PD ("Presence detect") pins to determine RAM size? These are not implemented on all SIMMs. I remember having a TT-RAM-card in my TT where I would have to manually add jumpers to these pins as the SIMMs I had left all these pins floating even though they were 32Mb SIMMs.

* The SIMM in the first slot must be 16Mb or more, but there is no such requirement for the other slots.

[Arne]

I remember having a TT-RAM-card in my TT where I would have to manually add jumpers to these pins as the SIMMs I had left all these pins floating even though they were 32Mb SIMMs.

Might that be an aixTT? MagnumTT has additional jumpers/pull-ups in case the PD pins are not set (correctly).

I guess that the chance with RAMs that are organized symmetrically are higher they will run in a Milan. Mine has IIRC 192MB.

[PeterS]

So if you want to replace your ram in the Milan, I recommend to remove all the simms from the Milan and just start with one f the new simms in the first socket. This simm must 16 MB or lager. Than remove it and test the next one and the next one and the next. When all simms are working correctly just try them together.

I tried about 50 different combinations over about a 3 month period. It's not an issue with the combination of simms and each of the simms will work in isolation or with another 16MB for instance but adding multiple 128MB cards never worked.

I even built up the solder tracks on the simms to improve the connections and also glued tiny plastic shims onto the simms so that they sit tighter in the sockets. I think I eliminated any mechanical connection issues.

The mIlan spec says it can handle 512MB but it doesn't work. That was the point of my question.

Has anyone succeeded in getting 256MB or 512MB working ?

[frank.lukas]

For the 128MB PS/2 Simm there must no PD set ...

[PeterS]

For the 128MB PS/2 Simm there must no PD set ...

Are you talking about the Milan here ?

[frank.lukas]

Try it ...

[PeterS]

Try what exactly ?

I have got it to boot with a combination that I had before that gives 192MB, this was the best I've ever managed.

Slot 0 = 128
Slot 1 = empty
Slot 2 = 64
Slot 3 = empty

[PeterS]

Looking at the simm under magnification I can see 4 pairs of contacts PD1, PD2, PD3 and PD4.

PD1 has a surface mount item on it, a resistor presumably.

[PeterS]

I had another attempt to get more than 192MB working but it failed.

The 128MB simms don't seem to make a good connection in the sockets. The others simms I have can be a little unreliable, taking a few attempts to get them seated so that they are detected.

If the 128MB aren't seating very well then this may explain why I can't get more than one to work.

[PeterS]

Is the 512MB limit on the Milan based on the fact that it can only take 4 EDO cards and the largest ones are 128MB ? Is there any addressing limitation ?

I wondered if another type of 1GB memory card could be added in some way ? I don't know anything about the various types of memory card such as voltages, addressing, identification etc.

[Arne]

I currently have 144MB in the Milan which is made up of 64, 32, 32, 16.

Does anyone have a Milan with more than this ?

I just undusted my Milan. It's equipped with four 64MB SIMMs giving 256MB total.

[joska]

Interesting. I have a 64Mb SIMM but it's not recognised by my Milan at all.

[frank.lukas]

See the Magnum TT PDF so you become an idea ...

[PeterS]

http://dev-docs.exxoshost.co.uk/Magnum_ ... glish).pdf

So that board has some jumpers but there are none that I know of in the Milan.

The Sims have 6540 chips.

[frank.lukas]

Ask Arne what typ of ram he has ...

[milthorst]

Mine was recently upgraded to 384MB by swapping two 32MB SIMMS for two 128MB SIMMs. Only problem is the thickness of the SIMMs, with chips on both sides, so they almost don't lock into the sockets like they should.

[PeterS]

I had the same problem, the sockets don't seem string enough to hold the simms.

Which slots do you have them in ?