Atari 800 problem

[Martin72]

Hi, i bought a Atari 800 and with gamecartridges like space invaders, ms pacman, crossbow etc, the computer works fine. Even with games from disk drive works fine. But when i attach the basic or assembler editor cartridge the computer hang up it self. It doesn't matter if i use dos or not.

There´s nothing then switch off and on the computer again.

I test the cartridges in a 600xl and 800xl and the cartridges works fine in this computers.

 

I have changed the CPU board and changed on the motherboard almost every chip, but nothing changed.

So my question is: what is the difference in what happened in a gamecartridge and the basic cartridge?

Could it be a problem in the ROM card (i have ntsc revA in it) or maybe in the RAM cards (3 x 16kB)?

Even the maxflash8mB cartridge from atarimax works fine.

I don´t know where i must look now. I don´t have another ROM chips then from a atari XL. Is it possible to place a eprom 27c128 with NTSC ROM ver.B in the ROM card or must i change many to the hardware?

 

Thanks,

Martin

[Sheddy]

Silly question, but, have you tried cleaning the contacts on the cartridges? - the cartridges just may not be seating in the same way in the 800 as the 600XL/800XL - slightly different connector sizes/angles etc. - unlikely, I know, but it seems such a strange problem (I've never owned an 800 myself though).

[Martin72]

Hi, thank you for the response. Of course i have cleaned the contacts. But the game cartridges (i tried 10 difference cartridges) work all fine, and the basic cartridge works good in a atari 600xl and atari 800xl. I have checked the contacts of the basic cartridge and the contacts of the 800

[Bryan]

One thing that makes a language cartridge different is that it tries to boot DOS, and a game does not. Perhaps you have a faulty OS ROM that is not able to initialize certain cartridges.

 

-Bry

[Martin72]

You're right, the assembler editor cartridge has the same problem. The boot proces works good, but after dos is loaded, the computer hang up again. So maybe you have a point. I think i must program a 2764 with another OS software. Has somebody experiences with this in a old 800 computer? There are three ROM´s. I think it is the best thing to leave ROM D and remove ROM E and F and place a 2764 eprom with OS software.

I can program this eprom after easter holiday. I will let you know if this works.

[Bryan]

One other thing to try is to swap the 16K RAM cards around and see if it behaves differently. This would indicate a bad RAM board.

 

-Bry

[Martin72]

Bryan, i have try this, but it makes no difference. I think i can trust the RAM cards because a large game for example "bounty bob strikes back" works good, and i think theni use the totally RAM memory!

[Bryan]

Then my guess is the ROM board.

 

-Bry

[Martin72]

I programmed an eprom 2764 with PAL-OS-REVA and test again the atari, but no differences with the original os rom (NTSC revA). The problem is still there....

I placed a PAL OS because i have rebuild the atari 800 to a PAL version. ( the problem was in original situation also present)

So, if somebody can help me with this problem, you´re welcome.

 

Martin

[Martin72]

I found the problem finally:

The 2k math pack /floating point pack was out of order.

Now the computer works properly with all programs!

 

Martin