Bad ECI?

[+Larry]

My 320K XE took a dive last night. Hate to lose those puppies with a lot of time invested in upgrades! It refuses to recognize a parallel device. It "died" slowly, and at first I thought it was my Black Box, but the BB works fine on another XE. This computer will boot fine from a floppy so long as as I use an 800 OS (which doesn't see parallel devices). It also will boot a cartridge fine, so long as an 800 OS is used. If the XE OS is used, it jumps to the Self Test mode and shows a "Bad Rom"

 

Any thoughts/suggestions as to where to start looking?

 

Thanks,

Larry

[+Guitarman]

Are you using something like a 32in1 OS mod??

[+Larry]

Are you using something like a 32in1 OS mod??

 

Hi-

 

No, I do use a 4-in-1 OS in Eprom, but I also removed that and inserted a stock XE rom -- same behavior.

 

-Larry

[drac030]

This computer will boot fine from a floppy so long as as I use an 800 OS

 

Can you check, when you boot it with the 800 OS, if the Atari BASIC works?

[a8isa1]

My 320K XE took a dive last night. Hate to lose those puppies with a lot of time invested in upgrades! It refuses to recognize a parallel device. It "died" slowly, and at first I thought it was my Black Box, but the BB works fine on another XE. This computer will boot fine from a floppy so long as as I use an 800 OS (which doesn't see parallel devices). It also will boot a cartridge fine, so long as an 800 OS is used. If the XE OS is used, it jumps to the Self Test mode and shows a "Bad Rom"

 

Any thoughts/suggestions as to where to start looking?

 

Thanks,

Larry

 

 

Do you have socketed ICs? If so try reseating the BASIC ROM, MMU, and any other ICs for good measure, and also your DRAMs on your memory expansion

 

- Steve

Edited March 2, 2007 by a8isa1

[+Larry]

This computer will boot fine from a floppy so long as as I use an 800 OS

 

Can you check, when you boot it with the 800 OS, if the Atari BASIC works?

 

Hi-

 

Yes, Basic comes up fine.

 

-Larry

[+Larry]

Do you have socketed ICs? If so try reseating the BASIC ROM, MMU, and any other ICs for good measure, and also your DRAMs on your memory expansion

- Steve

 

Hi Steve-

 

Pretty much everything is soldered except the expansion ram chips. I checked for loose/broken solder connections and re-seated all the ram chips. The memory expansion appears fine, but I probably should run a memory test on the expansion area.

 

-Larry

[drac030]

Yes, Basic comes up fine

 

So, if it goes directly to the memory test, this means that the ROM fails the checksum. 800 OS "works fine", because AFAIK it does not calculate checksums

 

I thought that perhaps the FP ROM got permanently disabled (this is where the PBI goes into), but BASIC wouldn't work then. It may be, that the damage appears in one of the places the 800 OS really doesn't use, i.e. $C000-$CFFF and SelfTest itself. If so, the left bar out of the two for the ROM in memory test should get red (or something).

[puppetmark]

My 320K XE took a dive last night. Hate to lose those puppies with a lot of time invested in upgrades! It refuses to recognize a parallel device. It "died" slowly, and at first I thought it was my Black Box, but the BB works fine on another XE. This computer will boot fine from a floppy so long as as I use an 800 OS (which doesn't see parallel devices). It also will boot a cartridge fine, so long as an 800 OS is used. If the XE OS is used, it jumps to the Self Test mode and shows a "Bad Rom"

 

Any thoughts/suggestions as to where to start looking?

 

Thanks,

Larry

 

Sounds like an address decodong problem. I would try replacing U2 the 74ls138. It could also be U3 which would have to be bought from Best Electronics.

[+Larry]

 

Sounds like an address decoding problem. I would try replacing U2 the 74ls138. It could also be U3 which would have to be bought from Best Electronics.

 

Thanks!