ST Memory upgrades...

[Tyrant]

Many many moons ago, back when ST's were still popular and supported, I had a 1Mb upgrade put into my 520ST. The upgrade used simms, and if I remember correctly there are two slots used and two unused. However, now I'd like to put it up to 4Mb, add a hard drive, and basically make it a totally uber machine.

 

However, does anyone know if most simm upgrade kits use the internal ram as well as the simms or not? In other words, are the two simms in mine 256k each (making half a meg, added to the half onboard to make one meg) or are they 512 each, making a meg and now using the 512 that was in the ST when it was bought?

 

This also raises the question of what size simms the ST can take in which slots, since I think most systems using 30 pin simms required them to be in pairs the same size. Logically I could use four 1Meg simms, is the onboard ram isnt used, if it is however, I cant work my head round how to get 4Mb on using only 4 slots if they have to be in pairs.

[Tyrant]

Ok having dived into my STFormat stack (and my ST ) I found a lovely article about ram upgrades, and worked out that Im 99% sure Im on an XTra-RAM Deluxe, and using a little utility I was able to work out that I actually posess four 256kb simms, which as expected do only work in pairs, and only one pair since you cant have 1.5Mb on an ST. STF does say that the board can take 4Mb but they dont specify how, since the onboard ram is still connected, and the only way to get 4Mb into 4 slots is four 4Mb simms, but that would be 4.5Mb with the half meg onboard, so Im more than a little confused, can anyone help?

[atarian1]

Most RAM upgrades (or the ones that I've seen) disable the internal RAM. I know the Marpet/Frontier Xtra-RAM Deluxe does this. So the computer just uses the RAM on the upgrade board.

[Tyrant]

Hmm... thats odd since when I take all the simms out, I still have a 512k machine, and when I put in what I think are 256k simms it becomes a 1Mb machine. Maybe tho when I put in 4Mb it'll drop the internal 512k and just use the simms. Im hoping this is what will happen, and I should be able to test later today, a friend still has some 1Mb sticks lying arround.

 

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HTML is on, so why dosnt a

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draw a horizontal rule?!?

 

Update:

 

I now have 4 1Mb simms in place, and memwatch is reporting I only have a 2.5Mb machine!? Im guessing this meens either two of the simms or two of the sockets are non-functional, unless anyone has a better explanation?

[ROOP]

I HAVE A 200MEG ST HDRIVE WITH CDROM RUNNING NVDI 4 ITS FAST AND WILL WORK WELL ON YOUR STE

IF YOU ARE INTERESTED LET ME KNOW I ALSO HAVE THE 4 MEG MEMORY SIMMS FOR AN STE

IM IN THE UK

[Tyrant]

Hmm... 200Mb is a little small (well no its not but I'm going to try to get a gig), I have an interface board on order already, just need to get a case / psu and cable now. Also I dont have an STE, if I did it would be easy, just take out the old ram and put in some new ram, I have an STFM with 512k onboard, as well as a Marpet Xtra Ram delux board with 4 simms, logically giving me 4.5 Mb (since I have 4 1Mb simms in it now) but instead two of them are ignored giving me 2.5Mb.... anyone know why?

[RucasRiot]

Hmm... 200Mb is a little small (well no its not but I'm going to try to get a gig), I have an interface board on order already, just need to get a case / psu and cable now. Also I dont have an STE, if I did it would be easy, just take out the old ram and put in some new ram, I have an STFM with 512k onboard, as well as a Marpet Xtra Ram delux board with 4 simms, logically giving me 4.5 Mb (since I have 4 1Mb simms in it now) but instead two of them are ignored giving me 2.5Mb.... anyone know why?

STFM, Why not STE?

[atarian1]

Hello again,

 

This is just a theory that came across my mind. Since the original RAM was not properly disabled, the ST may be confused when it sees 4.5MB of RAM since STs can only support up to 4MB. What I think is happening is that the ST sees the RAM in the computer first before the RAM in the upgrade board. Since the internal RAM has precedence over the upgrade-board RAM, the ST sees the 512K first, and then stumbles upon an extra 4MB that is totally foreign to the ST. In this confusion, the ST ignores the extra 2MB from the RAM board and reverts back to a known 2.5MB configuration since this is the last configuration it can see using both the internal and upgrade-board memory. STs can only see 512K, 1MB, 2MB, 2.5MB and 4MB configurations. (Did I word all that clearly?)

 

So to get 4MB, I think you really need to disable the internal RAM. Instructions to do this should be in the RAM upgrade instruction manual. (and I bet you don't have it, huh?)

 

 

P.S. What are you going to do with 1GB of hard disk space? I had a hard time filling up 200MB on my ST! Are you going to do lots of DTP or something?

[Tyrant]

Lol, I have no idea what I'll do with a gig, but the more space I can get the better. Since I've managed to fill up every drive I've owned for a pc with useless crap, Im sure I'll end up running out of space on an st too so why not start with as much spare as possible?

 

I had the same thoughts about memory, the only problem is as you guessed, I dont have a manual and I've no idea at all how to disable the onboard ram (which if Im not mistaken is actually soldered onto the board, if it was socketed I could try just unplugging it, but Im not going to even try desoldering chips.