130xe 320k upgrade by Tom Peterson

[Gunstar]

I just installed this upgrade yesterday. I just bought the "kit" from Best Electronics which comes with th instructions and needed hardware. My question about it is if there are any known problems with the original instructions as mine won't work. I turn my XE on and I just get a black screen with white diagonal lines. I checked my work and quadrupal checked it with the instructions, with no luck. It's a reletively simple upgrade without too many places things could go wrong, so I'm thinking maybe something in the instructions is missng. I know that some "upgrades" have had errors in the instructions that have needed to be corrected, so I'm asking anyone who has done this upgrade. Thanx.

 

Edit: I just found the instructions online, and comparred them to the ones I got with the Best E. 320xe "kit." there is one discrepency that I would like verification on: On the instructions I got with the kit it says (and shows a diagram) to connect a wire from pin 30 on the GTIA chip to pin 1 of the piggy-backed 74ls158 chip and in the online instructions it says to run this wire from pin 38 on the GTIA to pin 1 on the 74ls158 piggy-back chip. I'm guessing this is the problem I have, but want confirmation before I cahnge this wire. Thanx again.

Edited January 27, 2006 by Gunstar

[classics]

I believe you want pin 30, which is the o2 clock.

 

Make sure you also installed the jumper on the ls158, and the series resistor on the output.

 

Steve

[Gunstar]

I was really hoping that the pin 30/38 discrepency was the problem as now I'm los as to the problem. yes, I have the jumper going from pin 15 to pin 8 on the 74ls158 and the resister on the "output" from pin 4 on the 74ls158 to pin 1 on the ram "buss." I guess I'll have to take a soldering iron to everything again to make sure I've got it all securely soldered, but I'm and old pro at soldering so I don't think that's the problem.

 

The online instructions: http://aland.roarvgm.com/mods/5.html that are online clearly state pin 38 though, as the o2 clock, and the ones I got from Best E. says pin 30 and it has a diagram showing it.

 

Now, the actual ram chips I got with the "kit" are MB81256 chips instead of the called for 41256 chips, this wouldn't be a problem would it?

Edited January 27, 2006 by Gunstar

[Gunstar]

Well, I reversed the upgrade back to a normal 130xe, and I still have the same problem, so it's obviously not the upgrade that did it. unfortunately it looks like something else went wrong/bad while I was installing the upgrade, so I'm in deeper shit than I thought as I hardly know where to start looking for my problem.

[classics]

Well, I reversed the upgrade back to a normal 130xe, and I still have the same problem, so it's obviously not the upgrade that did it. unfortunately it looks like something else went wrong/bad while I was installing the upgrade, so I'm in deeper shit than I thought as I hardly know where to start looking for my problem.

1008040[/snapback]

 

Bummer. Did you have to desolder your RAM to install sockets? I'd check that for broken traces first.

 

Steve

[AlanD]

The online instructions: http://aland.roarvgm.com/mods/5.html that are online clearly state pin 38 though, as the o2 clock, and the ones I got from Best E. says pin 30 and it has a diagram showing it.

 

 

Didn't realize there was a discrepancy as these are ones I rescued from an old disk I had from back in the BBS days. Never tried the mod myself - only went as far as 256K on an 800XL. I'll correct it so there aren't any future issues.

Alan

[Gunstar]

Well, I reversed the upgrade back to a normal 130xe, and I still have the same problem, so it's obviously not the upgrade that did it. unfortunately it looks like something else went wrong/bad while I was installing the upgrade, so I'm in deeper shit than I thought as I hardly know where to start looking for my problem.

1008040[/snapback]

 

Bummer. Did you have to desolder your RAM to install sockets? I'd check that for broken traces first.

 

Steve

1008075[/snapback]

Yes, I did. But I did check for broken traces before soldering the sockets in place. But would I just get a black screen with thick diagonal white lines or black screen with one thick white line running down the right side of the screen if the ram is the cause? I've learned to hate sockets anyway as I changed out the Antic chip for a PAL Antic and followed the instructions to put in a socket there at the time, and I could never get it to work until I finally desolder the damn socket and soldered the chip directly to the board again. Then it worked fine. I think I'll do the same with the ram chips. The problem is that once the socket is in place, you cannot see if there are broken traces or if your soldering job is good becuase the socket hides it all! Sockets SUCK!

[Almost Rice]

The problem is that once the socket is in place, you cannot see if there are broken traces or if your soldering job is good becuase the socket hides it all! Sockets SUCK!

1008231[/snapback]

 

 

Really? I just tried to fix my XEGS and socketed every 40pin chip. I only did that to ease troubleshooting. I found out the system had a bad PIA chip. It starts now, but now games run irraticly and the Keyboard and sound does not work. I will be checking the Pokey socket again.

Edited January 28, 2006 by Almost Rice

[Gunstar]

The problem is that once the socket is in place, you cannot see if there are broken traces or if your soldering job is good becuase the socket hides it all! Sockets SUCK!

1008231[/snapback]

 

 

Really? I just tried to fix my XEGS and socketed every 40pin chip. I only did that to ease troubleshooting. I found out the system had a bad PIA chip. It starts now, but now games run irraticly and the Keyboard and sound does not work. I will be checking the Pokey socket again.

1008253[/snapback]

 

I understand the advantages, I love the fact that my 800 and 1200xl have mostly socketed chips, but they are factory done. I've just had a bad experience, possibly twice in a row now, and the fact is that if the socket is in place and there is a broken trace or bad solder point, you can't tell becuase the plastic housing covers the holes/rings. All you can see is the bottom side. With a chip directly on the board, at least you can see if the pins are soldered to the rings/traces on top too. I tried reinstalling a socket twice wit no luck, but the first time I decided to frack the socket and solder the Antic directly to the board it worked. Now, I probably have some bad solder points on my ram sockets, I checked the traces before I soldered them in, and from the bottom my soldering looks as good as the original, but I can't see my soldering for the sockets on the top side to find any possible problems becuase the hosocket housing completely covers it from my view.

[Artlover]

the fact is that if the socket is in place and there is a broken trace or bad solder point, you can't tell becuase the plastic housing covers the holes/rings. All you can see is the bottom side.

1008293[/snapback]

Not all sockets are a like. To that end, get machined pin sockets. Better quality on a whole and easier to hand solder.

[+bf2k+]

I did this upgrade MANY years ago and had the same black screen. Mine ended up being poorly soldered RAM chips (or sockets I forget if I installed them or not). Several passes with the soldering iron eventually solved it.

[Zonie]

Test your socket solder joints by measuring for continuity between the contact in the socket to the next point on the board where the trace goes. This will save you a lot of time and aggravation.

 

Did you practice safe ESD? You may have indavertantly fried a CMOS chip with static. I have seen it many times. Ployester carpeting and chair padding is a menace and you can zap a chip without even knowing it.

 

My 2600 controller port got zapped just sliding the console around on the carpet when I was a kid.

[Gunstar]

Well, I fainally got the upgrade working properly. It works great and it's great having 320K! The problem was indeed a broken trace, or rather "cut" trace. It was exactly what I thought it was, but I just had to try every other possibility first, beucase this trace would be so hard to fix. Why? Beucase this trace is one that was hidden under the PIA chip, a chip that is not removed in the uprgade, but you have a choice of either cutting the 15&16 pins from the motherboard, OR, cutting a certain trace and removing a resister. I chose the first choice and clipped the two pins at the motherboard, and in the process I also clipped a trace at a point just under the chip that is not visible unless the entire PIA chip is removed. Well, since I checked everything else, and it's quite a professional job if I do say so myself, I knew it was probably something exactly like it was. So after desoldering&removering the PIA I easily repaired the broken trace, that I knew I would find, with my trusty CircuitWriter pen. Tested it and I got the blue basic screen. Put it all back together and loaded up NUMEN to test the memory. Numen promptly said "A PAL Antic chip with a NTSC GTIA chip...unusual combination. trying and run it anyway."

 

By the way, Numen runs flawlessly, I have yet to find a PAL program that will NOT run properly without a PAL GTIA.

 

T-34 Tank battle is AWSOME too! I had a PAL Antic in my 1200XL, but not enough memory, and my XE had the memory, but the game would crash with a NTSC Antic. Now I put the PAL Antic in the 320XE and the NTSC into my 1200XL. I still need to upgrade the 1200's memory, I've had the supplies forever, I guess that's my next project. In the past few months I've installed the Super S-video mod, Warp+ 32-in-1 OS, corrected 5v SIO power problem, and installed newer XE version of NTSC Antic in the 1200XL. The 130XE had gotten the XE PAL Antic, 320k upgrade, a new keyboard and Myide external 5G hard-drive that I installed in an SF314 ST drive case so it matches the XE. Though it's the MyIDE cartridge, so I can use it on the XL too. I also now have the 8Mb flashrom for use with both machines. New pictures to come.

 

I do have one question/thought on my 1200XL memory upgrade, I've been planning a 1MB upgrade using Bob Woolley's 1200XL Simm upgrade, which I have been putting off becuase it does require a small circuit board to be built and lots of motherboard solder points. but now that I have an extra 8 64k memory chips that were removed from my XE to be replaced with the 256k chips, is there an upgrade for just a 128k XL instead of the usual 256k+ upgrades? Can I just piggy-back the chips onto the XL's chips (with the other proper components generally used in memory upgrades like the gate chips, etc.)? Is there instructions some place for only a 128k XL? I really don't need more than 128k in my XL, but I couldn't find any of the old comercial 256k upgrades like Rambo or Newell, so I was going to do the 1MB Simm upgrade since I have 30-pin 1MB simms laying around and most of the other needed components. I am lazy though, (and amazed I get as much accomplished upgrade-wise as I do) and would prefer the path of least resistence.

Edited February 5, 2006 by Gunstar