30 Pin SIMM upgrade

[flashjazzcat]

I've got an STE on the way with 1MB fitted (presumably 4x256K SIMMs). I want to buy 4x1MB SIMMs for it, but is there anything to worry about when choosing modules? Do they HAVE to be 70ns, non-parity? I read somewhere that the STE isn't picky about which SIMMs you use (as long as they're all the same, I imagine).

[+poobah]

I've got an STE on the way with 1MB fitted (presumably 4x256K SIMMs). I want to buy 4x1MB SIMMs for it, but is there anything to worry about when choosing modules? Do they HAVE to be 70ns, non-parity? I read somewhere that the STE isn't picky about which SIMMs you use (as long as they're all the same, I imagine).

 

Almost anything will work so long as they are the same and are Fast Page Mode SIMMS, NOT EDO.

[flashjazzcat]

Almost anything will work so long as they are the same and are Fast Page Mode SIMMS, NOT EDO.

That's great - thanks for the info!

[flashjazzcat]

520STE just arrived, with 1MB (4x256K) of RAM. In reasonable condition but a little green around the gills, so I'll be doing the peroxide treatment on it. Pretty nice for £6.49!

Edited May 12, 2009 by flashjazzcat

[puppetmark]

520STE just arrived, with 1MB (4x256K) of RAM. In reasonable condition but a little green around the gills, so I'll be doing the peroxide treatment on it. Pretty nice for £6.49!

 

 

Wow! Not bad at all! STEs are fairly rare in the states. I soldered a 4mb 72 Pin Simm (thanks to Techie Allison's great instructions) into my 520ST but I Still wish I had the other enhancements of an STE.

[nathanallan]

Very good deal, glad you snagged it!

 

@puppetmark; do you have a link to the instructions?? I have a 520ST that would love to be upgraded, and I am a sucker for a cute machine. Especially when it begs.

[flashjazzcat]

This has indeed proved to be one very sweet purchase indeed. It was quite green when it arrived yesterday, but needed only two hours' peroxide treatment to get it looking like this:

 

 

Compare with the SFTM (at the top of the picture) which is still yellow after eight hours treatment:

 

 

Anyway, I'm wondering what these jumpers are on the motherboard. Normal? (note piggy-backed 74LS164):

 

 

And the only fly in the ointment (DMA chip needs replacing):

 

[Chandler]

looks good

 

what is the procedure for cleaning up the casing if it's yellowed?

[flashjazzcat]

what is the procedure for cleaning up the casing if it's yellowed?

Described here and on the wiki here.

 

Things went wrong when I tried this on the STFM (the plastic bloomed and the end results generally weren't startling), but the STE has been a dream. Note that this time I used plain 40vol peroxide gel: no additives, Oxy, thickener or anything else.

 

Curious to know what that mod is...

Edited May 13, 2009 by flashjazzcat

[puppetmark]

@puppetmark; do you have a link to the instructions?? I have a 520ST that would love to be upgraded, and I am a sucker for a cute machine. Especially when it begs.

 

Try here:

http://www.logicsays.com/atari/72simm/

 

Some of the connection points for the 520ST are in different locations than the STFM but they are all there. I removed all the RAM chips from the motherboard and used the space for the SIMM. Also, you need a fast page SIMM and not EDO.

[nathanallan]

@puppetmark; do you have a link to the instructions?? I have a 520ST that would love to be upgraded, and I am a sucker for a cute machine. Especially when it begs.

 

Try here:

http://www.logicsays.com/atari/72simm/

 

Some of the connection points for the 520ST are in different locations than the STFM but they are all there. I removed all the RAM chips from the motherboard and used the space for the SIMM. Also, you need a fast page SIMM and not EDO.

I have some fastpage ready for it, pulled from a pc. Thanks!

 

Nathan

[puppetmark]

@puppetmark; do you have a link to the instructions?? I have a 520ST that would love to be upgraded, and I am a sucker for a cute machine. Especially when it begs.

 

Try here:

http://www.logicsays.com/atari/72simm/

 

Some of the connection points for the 520ST are in different locations than the STFM but they are all there. I removed all the RAM chips from the motherboard and used the space for the SIMM. Also, you need a fast page SIMM and not EDO.

I have some fastpage ready for it, pulled from a pc. Thanks!

 

Nathan

 

Good luck, Its a lot of soldering but well worth it. Allison's advice not to do too much at a time is good advice. I think it took me about 2 weeks till it was all done.

[flashjazzcat]

Can anyone tell me what those jumper leads are for?

[puppetmark]

Can anyone tell me what those jumper leads are for?

 

It appears that this is a baud rate enhancement Mod. it basically uses a shift register to double the standard baud rate of the ST serial port. I think it requires the use of a CPX module to take advantage of it. There were several versions of this kind of mod and I am not sure which one this is. I have instructions for a couple of these and it doesn't quite match.

 

*EDIT*

 

After some more research, it appears this might be a factory fix of some kind for this revision of the STE. This thread shows this chip on the Atari STE schematics yet there isn't a place for it on the motherboard. So this may have been added to later motherboard revisions:

 

http://www.atari-forum.com/viewtopic.php?f...506&p=21537

Edited May 20, 2009 by puppetmark

[vitaflo]

Can anyone tell me what those jumper leads are for?

 

It appears that this is a baud rate enhancement Mod. it basically uses a shift register to double the standard baud rate of the ST serial port. I think it requires the use of a CPX module to take advantage of it. There were several versions of this kind of mod and I am not sure which one this is. I have instructions for a couple of these and it doesn't quite match.

 

*EDIT*

 

After some more research, it appears this might be a factory fix of some kind for this revision of the STE. This thread shows this chip on the Atari STE schematics yet there isn't a place for it on the motherboard. So this may have been added to later motherboard revisions:

 

http://www.atari-forum.com/viewtopic.php?f...506&p=21537

 

Most definitely done in the factory. Just received a stock STe a few days ago and after opening it, it had the same leads. Curious what it fixed, if anything.

[flashjazzcat]

Yay! Just received four 1MB SIMMs in the post bought for £1.50 from ebid (useful cheque-only alternative to ebay with much computer stuff on it). Popped them in the STE and they work perfectly. Now I have TOS 2.06, 4MB, good DMA chip... just waiting for Satandisk and am good to go!