130 XE with a 576K Upgrade

[Ray_A]

Hi folks this is my first posting to the forums here, so a hello to everyone is in order. My name is Ray and I am from Toronto, Ontario.

 

I was (and still is to some degree) an Atari enthousiast just like yourselves for many years. Played games, used productivity software and written programs for my Atari for several years. One of the other aspects of 8 bit Ataris I truly enjoyed was modding them.

 

One of the mods I did was the 576K Upgrade to my 130XE. It was a joy seeing it work after the mess I created inside the case . I used that 130XE for a while until one day I stored it with all my other 8 bit stuff in a cabinet in the basement. Several years later I took the XE out to see it working again but NO GO. The beast! would simply refuse to boot. It would power-up but nothing is displayed and nothing happens. It was the same result whether the 576K switch behind the unit is ON or OFF.

 

I am puzzled, how could it break sitting in a closet. I opened the case but there is no visible humidity damage. I checked all the solder points but couldn't find anything loose. So I am wondering if anybody else had a similar experience and whether they were able to fix it. I would love to see that machine come back to life but I am not sure how to diagnose it. So I am looking for a veteran hardware modder's opinion on this subject.

 

thanks a lot in advance.

 

P.S: I attached two pictures of the upgrade just in case if something wrong strikes you when you look at it.

 

Ray

[Marius]

Are you sure your power supply is still working?

 

If you turn on the atari 0% happens or a little? Is the screen coloured? Like red?

 

It could be:

 

1. Power Supply

2. Bad OS ROM

3. Bad RAM

4. Bad CPU

 

And anything else of course. But these are my personal experiences with chips/hardware that fails first. Especially a faulty OS Rom or a bad Ram.

 

Greetings

Marius

[Ray_A]

Are you sure your power supply is still working?

 

If you turn on the atari 0% happens or a little? Is the screen coloured? Like red?

 

It could be:

 

1. Power Supply

2. Bad OS ROM

3. Bad RAM

4. Bad CPU

 

And anything else of course. But these are my personal experiences with chips/hardware that fails first. Especially a faulty OS Rom or a bad Ram.

 

Greetings

Marius

 

Hi Marius, I checked the power supply and it's ok, works fine on another 130XE. When I turn the computer ON the only thing that I see is a momentary noise bar on the screen. It happens at the moment I flick the power switch on, and then nothing else. The computer is connected to a color monitor through the monitor port. I don't even get a color on the monitor, it's like nothing is connected to it at all.

[ethierbach]

Hi, Ray -- I'm fairly new here, too. When I had my A8s new in the 80s, I had never heard of modding them. Now that I have some again, I think I'm going to be having a lot of fun.

 

Please do try a different power supply first. My free(*) 800XL and 130XE both had the same symptoms as yours. I checked the power supply, and it was putting out the right DC voltage. However, I bought another 800XL recently, and tried its PS on them, and they fired up with no problem. I'm guessing the faulty PS was putting some AC on the DC voltage pins, or maybe it couldn't handle the current draw any more, or .

 

-Ed-

 

(*) As I've found with Amigas and Ataris, "free computer" is like "free puppy".

[ethierbach]

Hi Marius, I checked the power supply and it's ok, works fine on another 130XE.

 

Hey, no fair, you typed faster than I did. Hope you find what's wrong and get your "super 8" working again soon!

-Ed-

[Ray_A]

Hi Marius, I checked the power supply and it's ok, works fine on another 130XE.

 

Hey, no fair, you typed faster than I did. Hope you find what's wrong and get your "super 8" working again soon!

-Ed-

 

Thanks for the advise ethierbach, I tried two different PS on that XE and no go. I am almost certain that something is wrong within the computer itself. I guess I may need to get my old logic probe out (and learn how to use it first ) to try to diagnose it. Won't be easy without some help I am sure about that as I am not really experienced in electronics.

[Marius]

Hi Marius, I checked the power supply and it's ok, works fine on another 130XE. When I turn the computer ON the only thing that I see is a momentary noise bar on the screen. It happens at the moment I flick the power switch on, and then nothing else. The computer is connected to a color monitor through the monitor port. I don't even get a color on the monitor, it's like nothing is connected to it at all.

 

Are you able to exchange that CPU with a working one? It's the Mexico CPU ... they are BAD anyway. It's a start.

If that won't work, try the OS ROM... it's harder to replace... (if you are going to replace, place a socket in it...)

 

I'm not thinking of ram in the first place. Most of time a bad ram gives more action than only a noise bar.

 

Another little trick: try to start the Atari with a (simple) cartridge connected.

 

BTW: isn't there any solder broke off and fell between some pins anywhere on the mainboard?? It might be an unwanted solderbridge to ofcourse. Perhaps you should tap and shake a little (careful!)?

Good Luck,

Marius

 

p.s. I'm wondering: why do you have a XE with a basic chip dated 1979?? I thought those 1979 basics were only shipped in Rev. A XL systems? Or is it just the date, and does this XE has the rev. "C" basic?

Edited August 16, 2007 by Marius1976

[+Guitarman]

CO24947A is BASIC Rev.C. 1979 is probably the original Copyright year for Atari Basic and all other revs are covered under the original copyright.

[re-atari]

One of the mods I did was the 576K Upgrade to my 130XE. It was a joy seeing it work after the mess I created inside the case . I used that 130XE for a while until one day I stored it with all my other 8 bit stuff in a cabinet in the basement. Several years later I took the XE out to see it working again but NO GO. The beast! would simply refuse to boot. It would power-up but nothing is displayed and nothing happens. It was the same result whether the 576K switch behind the unit is ON or OFF.

 

I am puzzled, how could it break sitting in a closet. I opened the case but there is no visible humidity damage. I checked all the solder points but couldn't find anything loose. So I am wondering if anybody else had a similar experience and whether they were able to fix it. I would love to see that machine come back to life but I am not sure how to diagnose it. So I am looking for a veteran hardware modder's opinion on this subject.

The DRAM's in the XE series are known to go bad from ageing. This is particularly the case with DRAM's manufactured by Micron Technology. However, from your photo's I noticed you have Japanese (Mitsubishi and Nec) ones, and these are generally bullet proof. In the past few months there have been several threads dealing with this subject. I'd start by reading these posts, they were started by Mimo, Tezz, Urchlay, Larry and Allas. Do check out the sticky thread at the top of the list as well.

As a quick hint, it might be worth the effort to start with desoldering and socketing the DRAM's in bank 0, just like you did with bank 1. It will ease identifying and exchanging any defective ones by swapping the DRAM's.

If that doesn't solve the problem, the (Mexico) CPU might be the culprit, as Marius suggested. Check if it runs hot when the XE is switched on. If you burn your fingers when touching it for more than a second, it's toast (literally). Be aware you can't replace it with a standard 6502, as Atari used a custom version with a different pin layout. Replacements should still be available from BEST.

 

re-atari

Edited August 17, 2007 by re-atari

[Mathy]

Hello re-atari

 

You can replace a 6502C with a 6502. But it's not a drop-in replacement. You need more stuff to do so. Ask Guus Assmann. He should know as he developed the "upgrade".

 

Greetings

 

Mathy

[Defender II]

Hi folks this is my first posting to the forums here, so a hello to everyone is in order. My name is Ray and I am from Toronto, Ontario.

 

One of the mods I did was the 576K Upgrade to my 130XE. It was a joy seeing it work after the mess I created inside the case . I used that 130XE for a while until one day I stored it with all my other 8 bit stuff in a cabinet in the basement. Several years later I took the XE out to see it working again but NO GO. The beast! would simply refuse to boot. It would power-up but nothing is displayed and nothing happens. It was the same result whether the 576K switch behind the unit is ON or OFF.

 

Hmmm... another challenge.

First from looking at your pictures, I see you have stacked the 256 chips for the 576k mod, which is quite a bit of

soldering, so you have some experience there.

 

Since the 130XE worked fine after your mod, those chips and everything else should still be fine, so you can look at things that happen over time. If the following don't work, your problem could be a cold-solder joint, which will be an extentive task of checking all of you solder connections.

 

1. The first step of checking the power supply has already been done, but never hurts to get another to check.

 

2. Two problems with sockets 'tho' is creep and corrosion. A. Creep is more common and happens over time as the chips heat up and cool down they work their way out of the sockets. B. Corrosion can happen if you didn't clean the pins well after soldering them. How to fix.

A. Carefully (extra carefully since the chips are all tied together with jumper wire) remove the chips and reseat them.

B. Since you are removing them you might as well clean the pins. An ink or pencil eraser carefully rubbed on both sides of the pins that go into the socket, then cleaned with a cotton swab dipped in isopropyl alchohol.

 

3. If it is not found above, most likely you will find a problem in the power or video circuits. Use your nose and eyes to troubleshoot. You can actually smell burned capacitors, resistors and diodes/transistors. Your nose should lead you to a deformed or burned component. Capacitors tend to get a rounded top. Some resistors and diodes actually burn in two like a fuse. Warning: I wouldn't reccommend sniffing or touching large capacitors from other power supplies (such as those used in some Arcade machines) due to PCBs.

 

4. Since your problem is no video your culprit could be the 40-pin GTIA -This is the chip which handles all color and luminance (brightness) information to send to the television screen. Hopefully you won't have to desolder & replace this chip, or the CPU or Antic. Save removing them as the last resorts in your troubleshooting.

 

5. If the 130XE was ever dropped you could have a hairline crack in your PCB somewhere and your signal tracer or voltmeter or ohm meter would help.

 

Good luck.

Edited August 17, 2007 by Defender II

[re-atari]

Hello re-atari

 

You can replace a 6502C with a 6502. But it's not a drop-in replacement. You need more stuff to do so. Ask Guus Assmann. He should know as he developed the "upgrade".

 

Greetings

 

Mathy

I know. Back in 1987 (or was it 1988?) I was in the process of designing my own PCB for plugging a 6502 or 65C02 in the XL, when Guus published the design by the Brabantse Hardware Freaks in Atari Magazine. As their design had more features, like an onboard OKI 5832 realtime clock, I abandoned my own design. I never got around to actually building one, as I had to catch up with my backlagging studies in college at that time, and about a year later switched to a PC.

 

re-atari

[Math You]

Can you load a game into the 130XE ? If you can hear sound coming through then it might just be a video problem.

[tjlazer]

Someone is seling a broken 130XE with this mod, is that the OP?

[Ray_A]

CO24947A is BASIC Rev.C. 1979 is probably the original Copyright year for Atari Basic and all other revs are covered under the original copyright.

 

you beat me to the answer, yes it is a rev C basic.

[Ray_A]

Great info guys, I'll check that CPU and see.

[Ray_A]

Again very good points, some I have thought about some not, I'll open the case and I will go over those points one by one.

On my first and second inspections I didn't see any burnt components. Also I pushed the ram chips in (carefully) to eliminate the possibility of loose chips (but should I really pull-them out fully and reinsert?). Haven't checked the CPU so I will do that too. Will see if i can come-up with something. And no the computer was never dropped, was just sitting in the closet for a long while.

[Ray_A]

Can you load a game into the 130XE ? If you can hear sound coming through then it might just be a video problem.

 

Nope the only thing that seems to work is the red power led, I will try inserting a cartridge though (as suggested above) and see what happens.

[+bob1200xl]

Can you load a game into the 130XE ? If you can hear sound coming through then it might just be a video problem.

 

Nope the only thing that seems to work is the red power led, I will try inserting a cartridge though (as suggested above) and see what happens.

 

When you power on, the reset line is held down for a few ms while the power stabilizes. Once RESET goes high, the CPU loads the address in the ROM at $FFFC,D and jumps to it. This means, at the very least, all the address lines should go high (except for A1) at least once. I wish we could auto-repeat RESET some way but you'll have to just press the key while you're probing the address lines. I've had the best luck just looking for hot chips, particularly memory. Otherwise, start with the oscillator and work your way in. You have quite a job ahead of you. It can be almost anything on the m/b, I'm afraid. And, it's all soldered in.

 

Bob

[Ray_A]

Can you load a game into the 130XE ? If you can hear sound coming through then it might just be a video problem.

 

Nope the only thing that seems to work is the red power led, I will try inserting a cartridge though (as suggested above) and see what happens.

 

When you power on, the reset line is held down for a few ms while the power stabilizes. Once RESET goes high, the CPU loads the address in the ROM at $FFFC,D and jumps to it. This means, at the very least, all the address lines should go high (except for A1) at least once. I wish we could auto-repeat RESET some way but you'll have to just press the key while you're probing the address lines. I've had the best luck just looking for hot chips, particularly memory. Otherwise, start with the oscillator and work your way in. You have quite a job ahead of you. It can be almost anything on the m/b, I'm afraid. And, it's all soldered in.

 

Bob

 

True. it's quite a job and I am not up to undertaking it right now (maybe never). Today I examined the board very carefully, nothing seems to be physically wrong (no burnt components, no loose solder point etc..), so it boils down to heavy duty diagnostics which is way above my head with my limited knowledge and equipment.

 

When I can spare some time, I will undo the upgrade though and see if the base configuration still works. If it doesn't then this 130XE will probably go to the spare parts bin. My other one is stock (128K) and works just fine, although I may need a new keyboard or a CPU if they ever fail. By the way the working machine has a NEC 6502 not the Mexican made CPU like the dead one.

Edited August 19, 2007 by Ray_A

[JamesD]

I'd guess it's a cold solder joint. You might retouch the solder connections.

[hunter44102]

I have the same/similar issue with my 576k XE that was stored a long time. However one time it booted and said 'no OS found'.

 

So it is on the cusp of working. The 576k eliminates the Basic rom correct? Or was there a way to hold something during power up to get to basic

[1050]

Except it doesn't say that.

 

It can say however depending on the disk in the drive:

No DOS found

That would be a SpartaDOS disk that hasn't had the BOOT command run on it

or it genuinely does not even have a .DOS file on it to load DOS from.

 

Incorrect on BASIC rom, it is turned off by powering up with OPTION button held

down unless your OS has this function flipped which would make it a custom

OS. No buttons down during powerup should land you at the READY prompt

which is BASIC in charge. If you now get 'No DOS found' press ENTER and

you should be looking at READY prompt. But I'm very weak in Sparta

knowledge so the above may be all wet.

 

576k has no conflict with BASIC or no BASIC either.

[gianlucarenzi]

Well, I had a similar (almost identical setup) and I tried to powerup the Atari 130xe after more than 30 years. Black screen.

But, with VIDEO COMPOSITE SYNC. I supposed the ANTIC/GTIA are using PHI2 from CPU (so it is supposed to work partially) so a BLACK SCREEN means nothing to display in VIDEO RAM.

I started to socket ALL COMPONENTS and see what happens:

1- CPU SOCKET (same issue)

2- ANTIC SOCKET (same issue)

3- GTIA SOCKET (same issue)

4- PIA (was already socketed by the 576K MOD)

5- BASIC ROM SOCKET (same issue)

6- FREDDY SOCKET (same issue)

7- OS ROM SOCKET (it start but with SELF TEST) Hurray!!!! We have a winner!! The solder joints on the ROM Chips went bad due to aging.

 

After I decided to redo all the soldering wires who looked bad to me with new flux and solder, and adding the shrink-tube on each solder joint.

During this rework I broke off a couple of pins of the 41256 RAM chips and I ordered a bunch of them and replaced.

 

And after 15 nights of reworking here is the result:

 

 

[+Larry]

I've got to wonder if the OP ever got his XE working.  But I'd put money that his issue was in the upgrade, and taking it out was a really good plan. And in that upgrade I'd bet there was a bad solder connection. We'll probably never know...