Have an 800XL that doesn't like some cartridges

[+GoldenWheels]

I wanted to get back into some 8 bit action; I have an XE but no keyboard (so an XEGS I guess, but I sure never called it that as a kid). So after a little research (all threads leading back to AA, as usual) I decided to get an 800XL.

 

Well I got my 800XL in the mail the same day as some new carts from an AA user.

 

My XE runs all the carts fine. But my 800XL won't play Football, Pole Position, Robotron, BC's Quest for Tires, and Dig Dug. Of games I already owned, I tried Joust, and, same deal, it worked on XE but not 800XL. The 800XL does play SOME of the other games I just got fine, including Ace of Aces and Barnyard Blaster. It plays some of my older games fine.

 

All carts were cleaned after an initial test in the XL, it made no difference. I can get more into my library of carts to test, I have a decent amount, but is there something KNOWN I should be looking at here? Or could I have gotten a faulty machine?

 

Cart connector need adjusting maybe?

 

Really hoping I don't have a dud and I can make this machine work. The 800XL makes my XE look (more) like a toy--though I will say, my XE's video is better.

[+DrVenkman]

Debris in the cartridge slot maybe? Get a bright light and look down into the connector and see if there's any hair or obvious debris impeding access to all the pins on both sides of the connector. I have a 5200 that arrived with almost literally hairballs inside. I used a very fine jeweler's screwdriver to just sort of fish it all out, then sprayed the connector with Deoxist before inserting and removing a cartridge a dozen times or so to clean off any dirt.

[Rybags]

Those are 16K cartridges, so maybe the problem is running that size.

 

https://www.atarimax.com/jindroush.atari.org/acarts.html

Lines RD4 and S4 are relevant here.

 

The obvious first thing to consider is are any of the working cartridges also 16K?

[griff3125]

If the carts are compatible, you might want to try some contact cleaner, that would get rid of any oxide buildup and clean the contacts.

Spray a little on a cartridge edge connector, then insert and remove the cartridge multiple times in the computer (of course with no power), let it sit for 15 minutes then try loading a cartridge normally.

https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU/ref=sr_1_3?keywords=contact+cleaner&qid=1560294129&s=instant-video&sr=8-3

[6BQ5]

You could also have some bad memory. One of the memory chips in my 800 (not a XL) had a bent pin and larger carts and games simply wouldn’t load. I stumbled upon the bent pin by pure accident when I decided to clean all the internal contacts.

 

Perhaps you have something similar happening? Maybe not necessarily a bent pin but maybe a faulty chip?

 

I confirmed my bad memory by running SALT. After straightening the pin and reinserting the chip everything was fine.

 

Doesn’t the 800XL have a built in self-test program? Try running it and see what the memory shows. It may not test as thoroughly as SALT but it’s a place to start.

[+GoldenWheels]

Well, I opened it up to clean it last night....and now I get a rolling black screen after putting to back together. I royally futzed it up somehow. Dammit. Will try to just boot it up with no cart tonight (in my dejection I didn't think of that....been a while since I ran an A8!)

 

There were several spots on the backside of the board which looked icky. I wonder if they were the issue. Caps/resistors on top looked ok. But bottom of PCB did not on some of the joints. There was rusty corrosion.

 

Anyone around here fix 800XLs?

[+DrVenkman]

That “rusty corrosion” under some of the solder joints was probably just old flux. Likely not an issue but you can clean it off with 90% isopropyl alcohol and an old nylon toothbrush.

 

Yeah, lots of us fix or tinker with old machines but shipping them around can get expensive. I basically only work on my own stuff or for local friends. That said, I’m pretty sure there are plenty of vintage Atari folks in New England who’d be able to help you out.

[_The Doctor__]

double check the shielding isn't shorting or cutting into the pcb mask, also a picture of your power supply might be in order...NO INGOTS allowed!

[+GoldenWheels]

double check the shielding isn't shorting or cutting into the pcb mask, also a picture of your power supply might be in order...NO INGOTS allowed!

 

I may have not aligned the paper piece under the PCB correctly, I wonder if that could be allowing some bad contacts. Thanks, I'll check. I had a heck of a time getting the guts back in the case.

 

The 800 DID ship with an ingot PS, but thanks to AA I knew not to use it. Grabbed my 1A logo PS that I got with my XE.

[_The Doctor__]

I always suggest 1.5 amp or greater for all machines. Modded Atari and sio powered devs on the system I suggest 2A or greater.

800XL? joyports out last and joyports in first when assemble dissassemble

Edited June 12, 2019 by _The Doctor__

[+GoldenWheels]

I always suggest 1.5 amp or greater for all machines. Modded Atari and sio powered devs on the system I suggest 2A or greater.

800XL? joyports out last and joyports in first when assemble dissassemble

Well right now it's running the same XE it has been for the last 7 years so it's solid here at least. If I can get the 800XL fixed up I'll for sure get a better PS. Not sure I'll ever mod it but I know enough to plan that I might....

[Forrest]

FYI you can find high quality 5V 2.5A power supplies for $10 - these were designed for the Raspberry Pie and have a micro-USB connector. You'll need to splice in the DIN power plug to match your Atari.

 

https://www.8bitclassics.com/product/atari-xl-xe-power-supply/ also sells a 5V 2A power supply with the Atari connector for $14.99

[1050]

Cease and desist immediately, calling an XEGS an XE

is most offensive to both crowds that favor one over

the other as if it doesn't matter anyway. It always

matters.

 

I like both and have a keyboard for my XEGS, you can

get one too. Just kidding by the way, but you really

shouldn't go there.

 

I'll suggest a better clock IC for U18, currently a

74LS08 AND chip to be replaced by a 74HCT08 that has

a better and cleaner output signal with more authority.

One of the gates on this chip supplies the system Phase

02 clock and it's important that it's not lagging in

slow ramp up as too many stock LS08 chips tend to do it.

 

Unless you can find it cheaper, faster, or already have

one laying about as I do:

https://www.ebay.com/itm/5-x-74HCT08-7408-IC-Quad-2-Input-Positive-AND-Gate-USA-SELLER-Free-Shipping/323520369453

 

The 800XL also seems to like one other chip just because

they do and it is U30, a 74LS51 to have instead a 74HC51

for it's better waveform as well. This deals exclusively

with ram signal creation and I just swap them out too

with never a reason to be sorry.

 

https://www.ebay.com/itm/MOTOROLA-MC74HC51N-74HC51-10-PCS/362196274897

 

These are no longer carried by 'real' sources as a general

stock item on hand and ready to ship. I was surprised to

find some in fact. And of course I already have a stick

of new ones just waiting for my next 800XL already.

 

Once those two chips are serving up some decent waveforms

there might be further items to look at such as the MMU

perhaps if the condition continues to plague you.

 

It sure sounds like borderline timing issues either with

ram or chip selects and the above suggestions have always

worked aces for me in the past when I've had one acting up.

It makes them solid as a rock, just like they should be.

[Mclaneinc]

Its been mentioned but 100% make sure the cart slot pins are not bent or touching, I've seen this once or twice and its a royal pain as you have to be really careful when straightening the pins...Slow and sure if its them...