Looks like I ordered the wrong STFM RAM upgrade

[danboid]

My first exxos order arrived today but it would seem that I've ordered the wrong type of RAM for my STFM. :oops:

I ordered the STFM DRAM 512K SET 16 CHIPS ( 512K to 1MB) kit and the matching caps (item #0122) but it wasn't until the RAM arrived that I realised I need a different DRAM package for my board and I'm not sure exxos sells the RAM I need for a 512Kb upgrade? You can see my nekkid STFM board here:

https://forums.atariage.com/topic/36951 ... nt=5502299

Do you sell the DRAM chips I require? If so, would I be able to return the DRAM I ordered by mistake and swap it or pay the difference to get a 4 MB RAM upgrade if you don't stock the 512 Kb RAM upgrade I require?

Thanks

[rubber_jonnie]

My first exxos order arrived today but it would seem that I've ordered the wrong type of RAM for my STFM. :oops:

I ordered the STFM DRAM 512K SET 16 CHIPS ( 512K to 1MB) kit and the matching caps (item #0122) but it wasn't until the RAM arrived that I realised I need a different DRAM package for my board and I'm not sure exxos sells the RAM I need for a 512Kb upgrade? You can see my nekkid STFM board here:

https://forums.atariage.com/topic/36951 ... nt=5502299

Do you sell the DRAM chips I require? If so, would I be able to return the DRAM I ordered by mistake and swap it or pay the difference to get a 4 MB RAM upgrade if you don't stock the 512 Kb RAM upgrade I require?

Thanks

This is why it pays to open your machine before ordering.

You would be better off in this instance with a 4MB Shifter/MMU upgrade as those surface mount RAM IC's are a bit hard to find and quite hard to fit.

You might want to PM @exxos directly about it.

[danboid]

Thanks rubber_jonnie, I have PM'd exxos.

The annoying / embarrassing thing is that I DID open my machine before ordering. I had a quick look and I knew that I needed 16x DRAM chips, I only saw one STFM 16x DRAM chips option on exxos' web store so I thought that must be the right memory upgrade for me. Nope!

As you can tell I didn't inspect the photo of the chips and do a visual comparison to the DRAM pads on my board. I was previously under the impression that STFM's had only 2 possible memory configs - 8 DRAM sockets or 32 but now I know there are at least 3 different types. How many RAM variations are there for the STFM models?

[rubber_jonnie]

Thanks rubber_jonnie, I have PM'd exxos.

The annoying / embarrassing thing is that I DID open my machine before ordering. I had a quick look and I knew that I needed 16x DRAM chips, I only saw one STFM 16x DRAM chips option on exxos' web store so I thought that must be the right memory upgrade for me. Nope!

As you can tell I didn't inspect the photo of the chips and do a visual comparison to the DRAM pads on my board. I was previously under the impression that STFM's had only 2 possible memory configs - 8 DRAM sockets or 32 but now I know there are at least 3 different types. How many RAM variations are there for the STFM models?

I wouldn't beat yourself up about it :)

I know of probably at least 4 different configs, two of which are through hole, one like yours, and another which IIRC is also surface mount, but uses fewer RAM IC's.

Be careful not to assume all machines are the same, there is a lot of variation, I'd suggest a look here: Motherboard Revisions as it'll give you a clue how much variance there was with the STFM and other ST variants.

Be aware that there are some variants that don't have a socketed MMU/Shifter as this restricts your upgrade options considerably.

[danboid]

Thanks RJ!

Wow thats a lot of STFM revisions they did, and I've noticed that not every revision has its own topic in that subforum. Seems you have the same yellow screwdriver as me :D

I tore down my STFM again today to resolder the joystick ports so whilst I was at it I checked that my shifter is socketed. Thankfully it is which means I should be able to install the 4 MB RAM shifter upgrade, right?

STFM-shifter.jpg