Hi,
yesterday I´ve found an interesting thing, which I didn´t know until now. On pin "S" of the cartridge-slots of an Atari 800 there´s not the "PHI2" signal attached as on all newer machines - there´s "RAS" connected. The falling edge of PHI2 and RAS is nearly the same, but RAS is much shorter low than PHI2 (of course, there must be some time for CAS, too).
Most modern circuits (in flash-carts or flashable carts) sample the PHI2 signal for their logic. So I think, this might be most significant reason for problems while writing to flash-memory or using special carts like the myIDE II.
See the signals on the scope:
![Scope.jpg]()
So I try a little modification and use PHI2 on pin "S" instead of RAS. And these seems to be the solution... myIDE-II works now without any issues in an Atari 800 with Incognito. Also some other carts with suspicious failures works now.
I test this on two Atari 800 equipped with Incognito. On one machine I take the Incognito out and re-install the old genuine personaliy and RAM cards. Also everything works fine. I have only one cartridge with "Write to cart" features which works on the original old 800 system: Telelink II. But this also works fine with that patch.
If you want to do this patch by yourself, here´s a possible way:
![Mod_e.jpg]()
Cut the RAS trace on the place in the picture.
![Connect_e.jpg]()
Connect pin "A" and pin "S" on the "right" cartridge slot together - that´s all!
This mod is independent which TV system you have, it works also on NTSC as on PAL or SECAM.
Regards, Jurgen
yesterday I´ve found an interesting thing, which I didn´t know until now. On pin "S" of the cartridge-slots of an Atari 800 there´s not the "PHI2" signal attached as on all newer machines - there´s "RAS" connected. The falling edge of PHI2 and RAS is nearly the same, but RAS is much shorter low than PHI2 (of course, there must be some time for CAS, too).
Most modern circuits (in flash-carts or flashable carts) sample the PHI2 signal for their logic. So I think, this might be most significant reason for problems while writing to flash-memory or using special carts like the myIDE II.
See the signals on the scope:
So I try a little modification and use PHI2 on pin "S" instead of RAS. And these seems to be the solution... myIDE-II works now without any issues in an Atari 800 with Incognito. Also some other carts with suspicious failures works now.
I test this on two Atari 800 equipped with Incognito. On one machine I take the Incognito out and re-install the old genuine personaliy and RAM cards. Also everything works fine. I have only one cartridge with "Write to cart" features which works on the original old 800 system: Telelink II. But this also works fine with that patch.
If you want to do this patch by yourself, here´s a possible way:
Cut the RAS trace on the place in the picture.
Connect pin "A" and pin "S" on the "right" cartridge slot together - that´s all!
This mod is independent which TV system you have, it works also on NTSC as on PAL or SECAM.
Regards, Jurgen