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 Post subject: AtariMax 8mbit flast cart loading issue
PostPosted: Tue Feb 06, 2024 11:38 am 

Joined: Mon Feb 06, 2012 11:36 pm
Posts: 4
Hopefully somebody here can kind of shed some light on my situation. I have an Atari XEGS at when I put the Atari Max 8 MBit flashcart in It takes several power cycles to get it to boot. It boots either to a black screen, the memory test, or some random game on the cartridge. I'd kind of like to know how the Atari Max 8 MB flash cartridge works with the MMU, the ready lines, cartridge control and all that on the Atari so I can probe and find out what might be going on. I know it doesn't work like a normal cartridge as on and off functions are controlled by software but i would like to know a little more like memory locations and other things so I can get to the bottom of this. I was thinking it might be an MMU but I've replaced it with a freshly burned gal so that does not seem to be the problem. BTW regular cartridges load and play just fine .Any help would be appreciated. Thanks in advance.


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 Post subject: Re: AtariMax 8mbit flast cart loading issue
PostPosted: Wed Feb 07, 2024 3:46 am 
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Joined: Sun Nov 02, 2003 8:15 am
Posts: 1561
Location: netherlands
It should work ok though.
Normally starts up at bank 0 (older production 8mb) or bank 127 (current cartridges).
Make sure the cartridge content can start from either bank (normally it should).

You can select a bank by writing any value to $D5xx where xx is the bank you want.
values >127 switches the 8mb off, giving back the 8k system ram.

Succes, Sijmen.


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 Post subject: Re: AtariMax 8mbit flast cart loading issue
PostPosted: Wed Feb 07, 2024 10:28 pm 

Joined: Mon Feb 06, 2012 11:36 pm
Posts: 4
I figured out what it was, or at least it "fixed" it. I replaced the 74ls08 with a 74f08 inside the XEGS and it boots every time now. It just needed a little faster chip to buffer the O2/PH2 signal. Scoping it, I noticed the Max cart was booting up faster then the O2 signal was getting to it by just a few nano seconds. Went from 13.2ns to 5.7ns delay prop with the chip change. I knew it was something hardware related because the Max cart works on all my other 8bits. I failed to mention that before, my bad guys.


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