Memo Pad works but Atari BASIC = black screen

[CZroe]

I know almost nothing about using my Atari 800 as I didn't want to dive down that rabbit hole until I knew it could at least power on. Well, I finally obtained an AC adapter power supply for my and turned it on only to see a blank screen. I removed the Atari BASIC cartridge and Memo Pad loaded just fine.

 

I took a quick look on YouTube and I saw how to remove the cover to access the OS ROM and RAM expansion slots. Like most, I found it fully populated with 16K RAM cards and 10K OS ROM, though the first 16K RAM card had a different color label (obviously the pack-in). I removed the rear 16K cards and tried each one-by-one in the 16K configuration (10K ROM + 16K RAM in first two slots only). I tested with and without the Atari BASIC and I always got a blank screen with Atari BASIC inserted, Memo Pad with it removed. Well, there were a few times that I got Memo Pad with Atari BASIC inserted but reseating it gave me the black screen.

 

Am I doing something wrong and I just don't know how to boot to the cartridge? I assume I'm doing it right (plug in left slot, turn on) since I get a different result with it inserted. Any idea what might be wrong? I inspected it pretty closely and the worst thing is that a few of the keys almost fall right off (still work fine though).

Edited July 3, 2016 by CZroe

[Rybags]

Probably dirty contacts on the cartridge meaning it's malfunctioning.

 

To get at the contacts you just need to insert something into the lockout mechanism so you can push it in and expose the edge connector. Then preferably clean with electrical contact cleaner or isopropyl alcohol.

Do the initial clean, then apply some more and insert into the computer (not powered on) to give it's connector some attention.

Then clean the edge connector again.

 

Leave everything to dry for a few minutes, for the most part those 2 types of cleaners will evaporate themselves and not leave conductive residue. Then try Basic again.

 

Sounds like your Ram boards are OK, so best to leave them be for now.

[CZroe]

Thanks, but I've already cleaned and recleaned since the foam tape holding the door's EMI shield degraded and was sprinkling little bits everywhere. I don't think that's it.

 

Here's a video showing what it does:

 

I don't have any other carts to test.

[Rybags]

Next thing - I should have suggested as well straight up but forgot about it.

 

I've just verified with a brown Basic cart I've got - open it up by taking the screw out and remove the metal cover.

You should have 2 socketed ICs. As per many old ICs that are socketed and not been used in a while, they can get oxidization.

 

The cure is just lever the chips out slightly and reseat them. Probably easiest to do so with the board pulled out. When pulling it out, note the placement of the spring and dust cover.

Easy way to lever chips is not with an IC puller but just something like a flat precision screwdriver, you only need to lever each end up by about 1mm or a little less. Then reseat and try again.

 

You can run carts as bare boards, just be very careful though to properly orient them, ie don't insert wrong side around.

[CZroe]

Wow. I knew from googling that all the chips inside the computer were socketed and I was already preparing to reseat those next but I didn't realize the ROM in the cartridge might be socketed too! I'll definitely check that first, especially since the issue only appears when running ROM carts. Thanks!

[+DrVenkman]

Wow. I knew from googling that all the chips inside the computer were socketed and I was already preparing to reseat those next but I didn't realize the ROM in the cartridge might be socketed too! I'll definitely check that first, especially since the issue only appears when running ROM carts. Thanks!

 

 

That's not true of all revisions of the 800XL. Most are socketed, some are not. 600XL's seem to be uniformly socketed.

[CZroe]

 

 

That's not true of all revisions of the 800XL. Most are socketed, some are not. 600XL's seem to be uniformly socketed.

I also knew that from the same googling, but it's not an XL. Thanks, though. When I'm done trying to order my Hi-Def NES, I'll break out the screwdrivers.

Edited July 4, 2016 by CZroe

[+DrVenkman]

I also knew that from the same googling, but it's not an XL. Thanks, though. When I'm done trying to order my Hi-Def NES, I'll break out the screwdrivers.

 

 

Ah, my mistake. I've been following another thread where someone is troubleshooting an 800XL and I had the two threads conflated in my mind.

 

Yes, the 800 is fully socketed, even the RAM boards. That said, disassembling an 800 is a LOT more involved than disassembling an XL/XE. More bits and pieces involved. Take your time and pay close attention to what you're doing and it'll go fine though.

[russg]

I know almost nothing about using my Atari 800 as I didn't want to dive down that rabbit hole until I knew it could at least power on. Well, I finally obtained an AC adapter power supply for my and turned it on only to see a blank screen. I removed the Atari BASIC cartridge and Memo Pad loaded just fine.

 

I took a quick look on YouTube and I saw how to remove the cover to access the OS ROM and RAM expansion slots. Like most, I found it fully populated with 16K RAM cards and 10K OS ROM, though the first 16K RAM card had a different color label (obviously the pack-in). I removed the rear 16K cards and tried each one-by-one in the 16K configuration (10K ROM + 16K RAM in first two slots only). I tested with and without the Atari BASIC and I always got a blank screen with Atari BASIC inserted, Memo Pad with it removed. Well, there were a few times that I got Memo Pad with Atari BASIC inserted but reseating it gave me the black screen.

 

Am I doing something wrong and I just don't know how to boot to the cartridge? I assume I'm doing it right (plug in left slot, turn on) since I get a different result with it inserted. Any idea what might be wrong? I inspected it pretty closely and the worst thing is that a few of the keys almost fall right off (still work fine though).

 

most likely a defective cart. You need a second cart or computer to test that. If you can hook up an APE/SIO2PC device, then you could load a binary load BASIC from a DOS disk.

That's just another way to get BASIC, won't answer the problem with your cart.

[russg]

 

most likely a defective cart. You need a second cart or computer to test that. If you can hook up an APE/SIO2PC device, then you could load a binary load BASIC from a DOS disk.

That's just another way to get BASIC, won't answer the problem with your cart.

 

here's a .ATR with the three BASICs, binary load on a MyDOS .ATR

BASICS.ATR

[+kheller2]

A agree. The cart is probably bad. You could also try cleaning the cart edge contacts with a good eraser. While it's possible something is broken with the cart slot or pins bent, it's highly unlikely. If you are in the states, someone could send you a cart... I think I even have several spares.

 

Now, that cart slot cover you kept moving out of the way in the video... I can't recall if my 800s have one! I must check! I must have it all!!

[CZroe]

LOL! It's not exactly a slot cover. It's the shielding that is supposed to be attached to the underside of the door but the foam part of the foam tape degraded into dust leaving two strips with a bunch of flaky crap stuck to it that rains all over the connectors below. It looks like I can see some of the same foam under the shield that covers the RAM/ROM cards, but I don't want to take it off and cause it to fall apart too.

 

Since then I peeled off the tape from both sides and it left plenty of adhesive to stick it directly on the plastic door. Even though they aren't two flat surfaces mated together, it's stuck plenty good enough. I'm guessing that they used foam tape so that there wouldn't be a gap when it closes to keep the FCC happy. I was more surprised that they went so far as to make the power shut off as soon as you open the door, which was probably also to keep the FCC happy.

 

Well, I was in the middle of a move when all this started and we still haven't unpacked any of the tools so the innards of the BASIC cart remain unmolested. I know a shop with some Atari 8-bit carts but I'm hesitant to spend more money without knowing that what I have works so I'll just wait until I can check inside the cart. The connector looks great so I hope hope to find out that it's the ROM socket and not the slot on the computer itself.

 

Thanks again, guys!

Edited July 6, 2016 by CZroe

[Rybags]

The foam crap might have got into the cart slots blocking a connection. Only takes 1 pin to stop it working.

[CZroe]

Yeah, but I cleaned pretty thoroughly and was pretty mindful about it.

 

I finally unpacked the toolbox this morning and checked the Atari BASIC cart: my ROMs are soldered and not socketed. It looks pristine, so I doubt that's the issue. There is an antiques store near me with a complete in-box Atari 800XL and several boxed software titles. He seems to be overcharging for everything (think, $50 for Star Raiders), but perhaps I'll be able to get something cheap enough to test.

 

Plan B: What's a good price to offer for his boxed 800XL?

Edited July 6, 2016 by CZroe

[CZroe]

Looks like I do have a pre-clean-up image of the degraded foam tape in my camera roll:

Full rez:

https://i.imgur.com/A6oUGnh.jpg

 

Shield is clearly supposed to be attached to the door above. Though the adhesive under the remaining strips is still very strong and clean, there isn't enough surface area on the ribs in the door to stick it permanently. I'm going to have to get some more foam tape.

Edited July 6, 2016 by CZroe

[Roydea6]

I have taken this metal shield off of my three Atari 800's and have seen no bad effects from the shield not being in place.

[CZroe]

Makes sense. Only reason it's there was out of an abundance of caution where they didn't want it (the computer) to have an effect on something else (TV reception). I only want to put it back because I don't know what else to do with it.

Edited July 6, 2016 by CZroe

[Roydea6]

Makes sense. Only reason it's there was out of an abundance of caution where they didn't want it (the computer) to have an effect on something else (TV reception). I only want to put it back because I don't know what else to do with it.

If you don't mind letting us know your location you might be local to someone on AtariAge that can help with getting a couple of cartridges to help with your repairs..

[Rybags]

Duct tape doubled over in lengths of a few inches would probably do the same job.

It's only foam tape uses to provide a little bit of movement since the design is such that it will insert carts for you if they're standard size and just sitting there - though it's not really a good idea to do it that way.

[CZroe]

If you don't mind letting us know your location you might be local to someone on AtariAge that can help with getting a couple of cartridges to help with your repairs..

Thanks. I borrowed Pitfall II from a local vendor and confirmed that it boots just fine. Now the problem is that I can't start the game! I know "Reset" works but Start/Select/Option keys don't appear to do anything. I went back and bought his boxed 800XL for $80 and found out that it has several bad keys too. D: One of the bad keys will respond if I push hard enough but it prints the wrong letter (pretty sure it was "H" printing "K").

 

Pretty bummed. What is it with Atari 8-bit computers and bad keyboards?!

[CZroe]

Well, I got the Start key to work by flooding it with 99.9% pure isopropyl while working it repeatedly and now it seems to be working like new. I still need to test the Option and Select keys but I'm not sure if they are supposed to do anything with the software I have (just Memo Pad, Choplifter, and Pitfall II). Is either Option or Select supposed to make a click in memo pad?

[Rybags]

Those keys don't click. And only Start has a function (tape boot) on a stock 800 with no cartridge present or software loaded.

 

Option and/or Select will have a function in most games.

[CZroe]

Thanks. You wouldn't happen to know if they have a function in Choplifter or Pitfall II, would you? They don't seem to do anything and I don't know if that's because these games don't use them or if they need the same treatment.

Edited July 12, 2016 by CZroe

[CZroe]

 

most likely a defective cart. You need a second cart or computer to test that. If you can hook up an APE/SIO2PC device, then you could load a binary load BASIC from a DOS disk.

That's just another way to get BASIC, won't answer the problem with your cart.

 

here's a .ATR with the three BASICs, binary load on a MyDOS .ATR

Thanks. I still need to get a disk drive, tape drive, emulator device, etc so I can use these.

 

...While it's possible something is broken with the cart slot or pins bent, it's highly unlikely.

Oh, man, if only that were true about the 800XL. When I started testing the 800XL with carts it was working fine (Memo Pad too) the first several tests I made, but it suddenly stopped working about four minutes later. Somehow two of the pins shorted in the connector (at least one looks mangled) and now I can't even boot Memo Pad. I tried Pitfall II, Choplifter, BASIC, and Pitfall II again testing repeatedly at each step. When I returned to Pitfall II it still worked until I pulled it out while the power was on and tried again, but I verified that the cart is fine in the non-XL 800. It had to be a freak coincidence or the Activision style cart shell with exposed PCB is prone to mangling connectors. The XL replaces the sturdy metal shielding/alignment stuff with jiggly snap-in plastic. Edited July 16, 2016 by CZroe

[Joey Z]

The XL replaces the sturdy metal shielding/alignment stuff with jiggly snap-in plastic.

 

Actually, they all had the same plastic piece, and the 400/800 didn't really have a snug enough fit in the shielding to provide much alignment.