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8bitguy1

Expanded RAM fix?

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Hi All,

 

Over the past few weeks I've noticed I've had significant issues running software that no one else seems to have. Bomb Jack crashes when I drop off the first ledge and LW won't load at all from SDX, so I ran Satantronics XRAM and sure enough it detected errors with my 320k 130XE. Unfortunately I did not do this upgrade myself so I'm hoping some one here is familiar with it and can help out. From MEM /X commands Draco (much thanks :) ) identified it as a Rambo compatible upgrade....well here is a pic just to be sure....I have 3 "E"'s generated by XRAM in what I'm assuming are banks of ram. Any thoughts on how/if this can be fixed? It's piggybacked on another chip and it has a bunch of pins cutoff.

 

Thanks

post-22559-1237670495_thumb.jpg

Edited by 8bitguy1

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Hi All,

 

Over the past few weeks I've noticed I've had significant issues running software that no one else seems to have. Bomb Jack crashes when I drop off the first ledge and LW won't load at all from SDX, so I ran Satantronics XRAM and sure enough it detected errors with my 320k 130XE. Unfortunately I did not do this upgrade myself so I'm hoping some one here is familiar with it and can help out. From MEM /X commands Draco (much thanks :) ) identified it as a Rambo compatible upgrade....well here is a pic just to be sure....I have 3 "E"'s generated by XRAM in what I'm assuming are banks of ram. Any thoughts on how/if this can be fixed? It's piggybacked on another chip and it has a bunch of pins cutoff.

 

Thanks

 

It looks like a regular Peterson 320K upgrade to me, but hard to trace all the wires in your photo.

 

Look at/compare the drawing at A8maestro's site:

 

http://www.a8maestro.com/atari/info/memory/mem130xe1.jpg

 

Do my eyes deceive me -- the bank (2) of 256 X1 chips are soldered in with no sockets? I wonder if the Tramiel's did the upgrade... ;)

 

-Larry

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Pfft.. Its blatently obvious from the photo.. Yeah that is a 'Scott Petersen' 320k XE.. All of the wiring shown in the picture is right.. Your problem is the ram chips, themselves, or a bad adress line on the board where they are soldered on.. Why in HELL would someone do an upgrade like that and not bother to put the new ram chips in sockets... Blows my mind..

 

It is VERY easy for an inexperienced person to lift traces on a 130xe motherboard when desoldering chips..

 

I could fix it for you, if you dont mind paying shipping both ways..

Edited by MEtalGuy66

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Pfft.. Its blatently obvious from the photo.. Yeah that is a 'Scott Petersen' 320k XE.. All of the wiring shown in the picture is right.. Your problem is the ram chips, themselves, or a bad adress line on the board where they are soldered on.. Why in HELL would someone do an upgrade like that and not bother to put the new ram chips in sockets... Blows my mind..

 

It is VERY easy for an inexperienced person to lift traces on a 130xe motherboard when desoldering chips..

 

I could fix it for you, if you dont mind paying shipping both ways..

 

I don't actually mind paying shipping, but if its an easy to fix (since the border makes shipping a touch pricey, which is rather silly that for example Michigan is more expensive than the Yukon) I do have another option......though I'm green at soldering, my brother is a PLC programmer, robotic technician and solderer extrodinaire by trade....so I'm sure he can solder the sucker easily himself. Am I just replacing chips? If so where do I get the replacements? and if not....then I will probably ship it and thank you kindly for the favour...

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Pfft.. Its blatently obvious from the photo.. Yeah that is a 'Scott Petersen' 320k XE.. All of the wiring shown in the picture is right.. Your problem is the ram chips, themselves, or a bad adress line on the board where they are soldered on.. Why in HELL would someone do an upgrade like that and not bother to put the new ram chips in sockets... Blows my mind..

 

It is VERY easy for an inexperienced person to lift traces on a 130xe motherboard when desoldering chips..

 

I could fix it for you, if you dont mind paying shipping both ways..

 

I don't actually mind paying shipping, but if its an easy to fix (since the border makes shipping a touch pricey, which is rather silly that for example Michigan is more expensive than the Yukon) I do have another option......though I'm green at soldering, my brother is a PLC programmer, robotic technician and solderer extrodinaire by trade....so I'm sure he can solder the sucker easily himself. Am I just replacing chips? If so where do I get the replacements? and if not....then I will probably ship it and thank you kindly for the favour...

I get them off REALLY OLD PC motherboards.. Like 286 era...

But it might not be the chips.. It may be a damaged trace on the motherboard from the first time the chips were removed..

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Bomb Jack crashes when I drop off the first ledge

 

I had the same problem with Bomb Jack. I own Bernd´s 512k memory extension and thought, it was to blame. But checking my Atari showed, that it was a simple power problem! I used a PC power supply from motu. But it didn´t give my Atari full 5V, only 4.6 were on the board. Too less, Bomb Jack crashes exactly the way that you describe here.

With the original Atari power supply I got 4.98V: Bomb Jack doesn´t crash!

 

So first step for you should be to check the power supply! Take a simple multimeter and look, how much power your Atari really gets! It shouldn´t be less than 4.9V. If it is a little bit more than 5V it is fine, too.

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Isn't it easier to take a 256KB Dram Simm out of an Atari 1040STE and use that? It's easy to remove the right memory bank, and solder wires to a simm connector (or directly on the simm)

 

I have done three XE's this way, and I must say: perfect.

 

For some strange reason faster memory results in strange behavior... I think that has something to do with a bad refresh circuit.

 

but slower ram (like the 256KB simms in most STe's) do a fine job.

 

Greetz

Marius

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Isn't it easier to take a 256KB Dram Simm out of an Atari 1040STE and use that? It's easy to remove the right memory bank, and solder wires to a simm connector (or directly on the simm)

 

I have done three XE's this way, and I must say: perfect.

 

For some strange reason faster memory results in strange behavior... I think that has something to do with a bad refresh circuit.

 

but slower ram (like the 256KB simms in most STe's) do a fine job.

 

Greetz

Marius

do you have the instructions? Sounds like an interesting mod

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Well I could look that up for you, but I think you could find it out yourself too.

 

Just search for the pinout of this SIMM, and connect the right wires (Data and Adress lines) to the atari connections.

 

You also need one TTL IC (and a 130XE). One resistor and some wires.

 

The upgrade is just the same as any other 320KB upgrade. But instead of using normal DRAM chips, just use one SIMM.

 

A 41256 has only one DATA line. So 8 chips 41256 chips do have 8 Data lines. And every chip also uses only one adress line. It is 8 x 1bit. (look here for pinout: http://www.xs4all.nl/~ganswijk/chipdir/giicm/41256.txt )

 

The 256KB simm has all those adress and data lines on board, so you have to solder those lines to the right points on the mainboard. (Easiest is, to use those points on the locations where you removed the original 4164 ramchips (right bank).

 

I'm not sure, but I guess unused adress line has to be connected to ground....

 

Don't forget to connect other used lines like /CAS etc.

 

That must do the trick.

http://en.wikipedia.org/wiki/SIMM#Standard_pinouts

 

 

I have to look up how I did it exactly, but I know I found out it myself, so it must be very easy to do.

Marius

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This is very trivial stuff..

 

Each 256k DRAM chip uses 9 adress lines and one data line.. so to use a 30 pin SIMM instead, You hook A0-A7, RAS, CAS, WE, +5v, and GND from any one of the 8 chip sockets, to the corresponding pins on the SIMM.. Then the data line from each chip socket goes to one of D0-D7.. The order doesnt matter.. A8 comes from pin 4 of the 74LS158 in the scott petersen mod.. It really is that simple..

 

However, if all you are doing is a 320k mod, I vastly prefer sticking with the original chip-socket scheme, rather than completely frankensteining the thing.. If you are considering 576k or 1088k, then The space/power savings that SIMMs offer quickly becomes an issue worthy of consideration...

Edited by MEtalGuy66

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