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 Post subject: Problem with Secam XL
PostPosted: Wed Jul 20, 2005 4:47 pm 
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Joined: Thu Feb 12, 2004 3:44 pm
Posts: 63
Location: France - Paris
Hi everybody,

I guess that almost everybody here is using NTSC models but I would like to explain my problem with SECAM Atari and your cartridge.

All the software updates posted by Steven do NOT work for me. I mean, I can program the cartridge (either 1Mb or 8Mb), it works. I can boot on the cartridge, the menu is displayed. But when I try to run a file, it seems that some files are working and some files are not working. And when I boot a couple of minutes later, the working files on the cartridge are not the same !

I ran the diagnostic software posted by Steven and among all the SECAM models, some are showing errors and some are not. So it seems there is a kind of hardware problem but I can't determine if it comes from the Atari or the cartridge.

After many hours of programming, I still don't understand why there is a problem but now I know how to avoid it:

I found that when I did something like this:
STA $D500,x
to select a specified bank, it does not work every time. It works maybe 10 times and the next bank changing leads to a wrong bank.

Second, when I try to disable the cartridge using
STA $D580
then again, sometimes, a bank is still there.

But the most intriguing is that when I do
LDA TRIG3
STA GINTLK
...
JMP WARMSV
the Atari halts because of the check on TRIG3 and GINTLK during vertical blank interrupt !!!

To avoid all those problems, I rewrote a loader for the cartridge:
- Before flashing a cart, I compute a checksum for all 128 banks and I put it in the last bank. When I switch to a bank, I check that the content of the bank is the one I am expecting by computing again the checksum
- When I disable the cart, I check that the address $A000 is RAM.
- Before doing the Warm boot, I retry (kind of magic) several times to disable the cart and copy TRIG3 into GINTLK.

The loader, with all this code to double check the bank switching, is much more longuer in size that the boot code of Steven. But now it works every time and on all the SECAM models I have...but I still don't understand what was the problem. And I can only include roms or files in the cartridge but not ATR (I will do it as soon as I have time for that matter).

I just wanted to share my experience on SECAM problem. If anyone has any explanation (Steven ?)...

And the last word will be to say that I am very happy with these carts. That's a great idea.

Thank you,

Eric.


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 Post subject:
PostPosted: Wed Jul 20, 2005 8:36 pm 
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Joined: Tue Aug 05, 2003 9:55 am
Posts: 1036
Location: Cleveland, Ohio
Eric,

Your problem sounds typical of XL and XE units with timings that are a little 'off' from 'normal' NTSC units.

Have you tried the stable-xl modification here?

http://www.mathyvannisselroy.nl/stabiliz.txt

Nice work on modifying the code to verify the bank switches. :)

Steve


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PostPosted: Sat Apr 01, 2006 9:53 am 
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Joined: Thu Feb 12, 2004 3:44 pm
Posts: 63
Location: France - Paris
classics wrote:
Eric,

Your problem sounds typical of XL and XE units with timings that are a little 'off' from 'normal' NTSC units.

Have you tried the stable-xl modification here?

http://www.mathyvannisselroy.nl/stabiliz.txt

Nice work on modifying the code to verify the bank switches. :)

Steve

Hi Steven,

I tried this week to make MOD #1 and MOD #2 from the above link with no success. It does not change the results given by your cartridge tester.

Eric.


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PostPosted: Sun Jun 11, 2006 4:34 pm 

Joined: Sun May 28, 2006 8:02 pm
Posts: 11
Location: Netherlands
classics wrote:
Eric,

Your problem sounds typical of XL and XE units with timings that are a little 'off' from 'normal' NTSC units.

Have you tried the stable-xl modification here?

http://www.mathyvannisselroy.nl/stabiliz.txt

Nice work on modifying the code to verify the bank switches. :)

Steve


I'm having some problems with my 8mb cart and although I'm not that hardware savvy I guess it has to do with timings.

Most of the time my 800XL either doesn't boot at all (blank screen) or boots straight into thr self test. When trying to do the ram test it hangs, very occasionaly it can do the self test and then obviously only tests 48k ram.

Very intermittently I could run the cart test software and the cart is detected and the tests run fine. I also could program the cart two times but could not get the cart boot up.

I only one time got as far as this:

Image

I am in the proces of obtaining a second 800XL or 130XE to rule out a hardware defect on the 800XL side. I also do not have any other cart to test my 800XL but it runs fine games and demos.

Also as a question: Are these stable-xl modifications compatible with the Warp+ OS 32-in-1 upgrade?


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PostPosted: Sun Jun 11, 2006 9:34 pm 
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Joined: Tue Aug 05, 2003 9:55 am
Posts: 1036
Location: Cleveland, Ohio
The stable-xl mod is compatible with the Warp+ OS upgrade.

If your machine can't complete any of the self-test routines in the OS rom, then there is a hardware problem with the machine.

On 800XL computers I would replace the RAM first, this is the biggest point of failure on those machines.

Even though it passes the RAM test occasionally, the times it crashes could still be due to intermittent ram.

Steve


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 Post subject:
PostPosted: Mon Jun 12, 2006 12:50 am 

Joined: Sun May 28, 2006 8:02 pm
Posts: 11
Location: Netherlands
Ah, I see my text wasn't quite clear, the self test only hangs when the flash cart is inserted, when I don't have it plugged in the 800XL works fine, self test runs ok. I only have problems when the cart is inserted, I have to get my hands on another cart to test the 800XL.


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 Post subject:
PostPosted: Mon Jun 12, 2006 11:01 am 
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Joined: Tue Aug 05, 2003 9:55 am
Posts: 1036
Location: Cleveland, Ohio
How long ago did you purchase the flash cart?

Steve


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 Post subject:
PostPosted: Tue Jun 13, 2006 3:59 pm 

Joined: Sun May 28, 2006 8:02 pm
Posts: 11
Location: Netherlands
Just at the end of May, before the sale would end :wink:
I'm still trying to get hold of a 2nd XL or XE to test the cart first.
Will email you when it is the cart.


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