Atari 800 bootup problem

[shoggo147]

Hello All,

I just purchased an Atari 800 but am having a problem at switch on. Basically I get a screen full of zeros, when I power up with no BASIC or game carts installed. I have the OS cartridge fitted in slot1 and 16K carts in slots 2 & 3. To power the computer I am actually using a VIC-20 power supply but I checked the spec and this is almost identical to the Atari 9V AC power supply, so I am sure this is not the problem.

Initially I had an additional 16K RAM cart installed but with this I just got a blank red screen at switch on, so removed it as I presume there is a fault with one of the RAM chips. If I swap around the remaining RAM carts it does not make any difference. I have also tried re-seating all the chips on the carts and inside the machine and cleaning all edge connectors From a quick look around on the internet it seems like it could be a fault with the ANTIC chip. I do have an Atari 800XL but I am not sure if I could swap the ANTIC chip from this to test.

I have also tried a number of game carts and found the sound and some graphics e.g. sprites, do work fine. See below links to the three I have tried

http://youtu.be/xmrMnIcxV4I

http://youtu.be/wdNFOZFFdwE

http://youtu.be/-aMSCMpIx8M

 

Any suggestions would be much appreciated.

[Caterpiggle]

Yes, I do remember that in 1 time in my life on my Atari 800XL PAL. I never seen "UP" at the top & left corner but I seen ALL zero in the whole screen. And my Atari 800XL PAL is working fine. Just once time when I was a kid.

[sup8pdct]

Do you have a star raiders cart? Put that in and see what happens.

 

James

[+Stephen]

Also agree on the suspicion of ANTIC. Nice thing is, everything is socketed on the 800.

[shoggo147]

Hi James,

I found a Star Raiders cart. The link below shows what happened.

Its similar to the others where the sound and sprites seems OK but other graphics are corrupted.

 

http://youtu.be/JQ_3KWuinz0

[Rybags]

I'm thinking maybe some sort of memory select problem.

 

Can you try with just one Ram card, try each one seperately.

These cart games use fixed addresses and will all work with 16K. Actually, Star Raiders should work in 8K.

 

If you do have another Antic that can be tried, then may as well give it a go.

[russg]

Hello All,

I just purchased an Atari 800 but am having a problem at switch on. Basically I get a screen full of zeros, when I power up with no BASIC or game carts installed. I have the OS cartridge fitted in slot1 and 16K carts in slots 2 & 3. To power the computer I am actually using a VIC-20 power supply but I checked the spec and this is almost identical to the Atari 9V AC power supply, so I am sure this is not the problem.

Initially I had an additional 16K RAM cart installed but with this I just got a blank red screen at switch on, so removed it as I presume there is a fault with one of the RAM chips. If I swap around the remaining RAM carts it does not make any difference. I have also tried re-seating all the chips on the carts and inside the machine and cleaning all edge connectors From a quick look around on the internet it seems like it could be a fault with the ANTIC chip. I do have an Atari 800XL but I am not sure if I could swap the ANTIC chip from this to test.

I have also tried a number of game carts and found the sound and some graphics e.g. sprites, do work fine. See below links to the three I have tried

http://youtu.be/xmrMnIcxV4I

http://youtu.be/wdNFOZFFdwE

http://youtu.be/-aMSCMpIx8M

 

Any suggestions would be much appreciated.

Could be bad RAM card. You only need 16K to run carts, so try with just one RAM card, can't hurt to try. You can try chip swapping, Antic has been suggested, you can borrow it from your 800XL.

I'm assuming you have the game carts, if you're loading from a menu disk or DOS, then 16K won't work.

[ClausB]

All chips in the 800 are in sockets and over decades corrosion builds up and makes for poor connections. Reseating each chip in its socket is the first step in fixing an 800, before you start suspecting bad chips. If you're not sure how, search this forum for advice.

[shoggo147]

Thanks all for your advice.

I have managed to solve the problem, it was the ANTIC chip as suspected.

Swapped one out of my 800XL and the 800 then booted and ran fine.

 

Jut need to find another ANTIC IC now if anyone knows where I can get hold of one.

[+Stephen]

Hi James,

I found a Star Raiders cart. The link below shows what happened.

Its similar to the others where the sound and sprites seems OK but other graphics are corrupted.

 

http://youtu.be/JQ_3KWuinz0

I had a 400 which did this. It was a bad ANTIC.

[russg]

Thanks all for your advice.

I have managed to solve the problem, it was the ANTIC chip as suspected.

Swapped one out of my 800XL and the 800 then booted and ran fine.

 

Jut need to find another ANTIC IC now if anyone knows where I can get hold of one.

 

 

http://www.best-electronics-ca.com/ scroll to bottom of page.

 

www.myatari.com (B&C) select hardware and 'find' Antic. Has 'D' and 'E' versions, don't know about the two versions. Also has PAL version, I think.

 

There may be others. May have minimum order.

Edited May 12, 2014 by russg

[w1k]

never buy from www sites looks like from 1994..

[BillC]

never buy from www sites looks like from 1994..

I believe Bruce(B&C/myatari.com) now sells mainly through eBay, user ID myatari. This gives him little incentive to improve his webpage.

 

The last time I purchased items from him, a couple years ago, I emailed him and had items added to my order that he didn't have listed on eBay at that time. If he hadn't had the www.myatari.com webpage I wouldn't have known the non-eBay listed items he also had available. Since I'm in Canada it makes sense to combine as many items into a single order as possible to reduce shipping costs.