There's a whole layer for GND anyway..
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See here for more information viewtopic.php?f=20&t=7296
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DO NOT USE DEVICES WHERE THE IP CHANGES CONSTANTLY!
At this time it is unfortunately not possible to white list users when your IP changes constantly.
You may inadvertently get banned because a previous attack may have used the IP you are now on.
So I suggest people only use fixed IP address devices until I can think of a solution for this problem!
At this time it is unfortunately not possible to white list users when your IP changes constantly.
You may inadvertently get banned because a previous attack may have used the IP you are now on.
So I suggest people only use fixed IP address devices until I can think of a solution for this problem!
REV 3 - REV 5 - The beginning (ST536)
Re: REV 3 - REV 5 - The beginning (ST536)
The 330R load seems to help a lot and doesn't seem to upset the voltage by anything significant.
There's a whole layer for GND anyway..
There's a whole layer for GND anyway..
Re: REV 3 - REV 5 - The beginning (ST536)
Just found one problem. If I press down slightly on the SR98 transformer the ST resets 
Second problem - if I heat the PLD after a few seconds it also locks up. I wonder if that's the same issue as to why fast-slew doesn't work
Thing is - I don't know if heating the PLD up even works on the original TF536 at this point. It could be "normal"
EDIT:
Fast slew doesn't change the behaviour ..
Second problem - if I heat the PLD after a few seconds it also locks up. I wonder if that's the same issue as to why fast-slew doesn't work
Thing is - I don't know if heating the PLD up even works on the original TF536 at this point. It could be "normal"
EDIT:
Fast slew doesn't change the behaviour ..
Re: REV 3 - REV 5 - The beginning (ST536)
Being running GB6 for the past few hours and will leave it on overnight again...
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Re: REV 3 - REV 5 - The beginning (ST536)
Left on overnight..
Will leave it off for the weekend and see if it still works on Monday!
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Will leave it off for the weekend and see if it still works on Monday!
Re: REV 3 - REV 5 - The beginning (ST536)
3 days turned off.. Left it running GB6 this-afternoon and hit 76 loops..
Running front bench...
Running front bench...
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Re: REV 3 - REV 5 - The beginning (ST536)
Looking good!!
Re: REV 3 - REV 5 - The beginning (ST536)
There's some current modifications to the ST536 288XL series to address some issues I found the past weeks.
https://www.exxosforum.co.uk/atari/last ... tm#MOD2025
Most as mentioned before. A poor 100MHz clock drive to the SDRAM and 3.3V power issues. There is a new firmware on the same mod section which must only be used after doing the mods. Going back to other firmwares will damage stuff, so don't do it !
I am also working on another respin of the board. I am using a new regulator which should be better and the 3.3V rail will be split into a dual rail powered by 2 regulators instead of one. More HF bypassing caps (typically 4.7nF) will also be added.
BETA testers please do the mods and see how you get on. There could still be issues, but I feel they are hardware related not firmware related now.
Before the mods, it would run for hours at a time.. leave it off a while, go back and unstable again. Currently its been working fine this past week and running several hours on TTram tests and GB6.
https://www.exxosforum.co.uk/atari/last ... tm#MOD2025
Most as mentioned before. A poor 100MHz clock drive to the SDRAM and 3.3V power issues. There is a new firmware on the same mod section which must only be used after doing the mods. Going back to other firmwares will damage stuff, so don't do it !
I am also working on another respin of the board. I am using a new regulator which should be better and the 3.3V rail will be split into a dual rail powered by 2 regulators instead of one. More HF bypassing caps (typically 4.7nF) will also be added.
BETA testers please do the mods and see how you get on. There could still be issues, but I feel they are hardware related not firmware related now.
Before the mods, it would run for hours at a time.. leave it off a while, go back and unstable again. Currently its been working fine this past week and running several hours on TTram tests and GB6.
Re: REV 3 - REV 5 - The beginning (ST536)
Looks like I have my Saturday project here.
1 - Swap the 144 to the 288
2 - Make the mods listed
3 - flash the new firmware
4 - Test test test....
1 - Swap the 144 to the 288
2 - Make the mods listed
3 - flash the new firmware
4 - Test test test....
Re: REV 3 - REV 5 - The beginning (ST536)
Looking at the mod and for the most part it looks really straightfoward.exxos wrote: Wed Nov 26, 2025 7:51 pm There's some current modifications to the ST536 288XL series to address some issues I found the past weeks.
https://www.exxosforum.co.uk/atari/last ... tm#MOD2025
Most as mentioned before. A poor 100MHz clock drive to the SDRAM and 3.3V power issues. There is a new firmware on the same mod section which must only be used after doing the mods. Going back to other firmwares will damage stuff, so don't do it !
I am also working on another respin of the board. I am using a new regulator which should be better and the 3.3V rail will be split into a dual rail powered by 2 regulators instead of one. More HF bypassing caps (typically 4.7nF) will also be added.
BETA testers please do the mods and see how you get on. There could still be issues, but I feel they are hardware related not firmware related now.
Before the mods, it would run for hours at a time.. leave it off a while, go back and unstable again. Currently its been working fine this past week and running several hours on TTram tests and GB6.
The one question I had is about the 4.7nf capacitors. The note says "Solder a 4.7nF 0603 capacitor across every small cap on the bottom of the PCB." Does this mean to replace the existing ones or add the 4.7nf side-by-side?
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Re: REV 3 - REV 5 - The beginning (ST536)
The 4.7nf is in addition to the existing caps..coonsgm wrote: Fri Nov 28, 2025 10:07 pm The one question I had is about the 4.7nf capacitors. The note says "Solder a 4.7nF 0603 capacitor across every small cap on the bottom of the PCB." Does this mean to replace the existing ones or add the 4.7nf side-by-side?
Just solder them on the side of the ones already on the PCB..
Be careful though as it doesn't take much for the caps to unsolder off the board while trying to solder the new caps on!
Would be useful if you could scope before and after on that pin I sent to you in pm a couple days ago to see if there is any noticeable difference afterwards..