DFBX1 Issues

[Badwolf]

@Badwolf Thank you very much. I will do all the things you suggested. I will have some time on the weekend and we will see how far I get
Concerning the shielding I followed this guy:

https://nokturnal.pl/2023/07/atari-falc ... -expansion

@nokturnal does some great stuff. I hadn't seen that page, but will read it now. Thanks.

I see what you mean about the middle shield section, but, personally, I'd still remove it until you're 100% convinced you're stable. A little bit of unexpected pressure here or a touch of a line there and you could see trouble.

My idea behind that was simply to do the least mods possible to the machine and thus keep it in the most original state.

That's reasonable. But get it stable first.

And by the way, the acceleration itself seems to work as the benchmarks show.

That's good.

Get it into that base configuration mentioned above and use it for a few days to see if you can foment any problems with CPU acceleration alone.

Cheers,

BW.

[Kcr060]

@Badwolf Yes, I will do that and report. Thanks a lot.

I see that @stephen_usher even put on the whole upper shielding... wow, that's bold, but definitely interesting, that it still works that way. Although you definitely need some extension cables and switches for the jumpers then.

[nokturnal]

Hi, I "wrote that shielding has to go". Had to remove it, but maybe photo was misleading.. There's no way shielding will fit, also I didn't want to cut it(hate metal work)..

[stephen_usher]

Hi, I "wrote that shielding has to go". Had to remove it, but maybe photo was misleading.. There's no way shielding will fit, also I didn't want to cut it(hate metal work)..

I saw that you used heatsinks on the CPU and CPLD. Checking the temperatures on my system when it was running continuously the CPU never got above 40C (in a room at 21C) and the CPLD was only ever warm to the touch. As it is the top shield rests flat on top of the CPU and acts as a heatsink. If you're worried about the CPLD then trimming a Pi heatsink down so that its top touches the shield and sticking that on the CPLD so that it too can use the shield as a heatsink.

[nokturnal]

@stephen_usher Honestly I didn't measure temperature in this case ('case' .. ), I only rememebered that Amiga accelerators emitted alot of heat and I thought that it could extend logevity, still cpu emits some heat (I've got 40MHz variant, I wonder how it is with 50MHz one). Nice idea with keeping the shielding, but I always wanted be on the safe side, maybe I will reconsider it.. Do you have links to photos?

[stephen_usher]

I replaced some of the vertical headers with right-angled. The clock one so that there was no chance that the shield above would hit that before resting upon the CPU heat spreader and the disable and ROM select ones so that I could take those out to external switches.

IMG_4127.jpeg (263.82 KiB) Viewed 552 times

IMG_4130.jpeg (233.82 KiB) Viewed 552 times

[VadimK]

So, I finally measured my PSU with multimeter and I'm right on the edge with 5.013V. I guess it's time to do recap.
I'll report back when I have clock patch and recap done.

[Steve]

So, I finally measured my PSU with multimeter and I'm right on the edge with 5.013V. I guess it's time to do recap.
I'll report back when I have clock patch and recap done.

Where did you measure? Make sure to take a reading at PSU end and then at the motherboard end (ie; on the DFB itself) to check for voltage drop.

[Badwolf]

So, I finally measured my PSU with multimeter and I'm right on the edge with 5.013V. I guess it's time to do recap.
I'll report back when I have clock patch and recap done.

Where did you measure? Make sure to take a reading at PSU end and then at the motherboard end (ie; on the DFB itself) to check for voltage drop.

Of course the best place to measure is the 5V and GND jumper just below the 030 on the DFB1X board itself.

If you're getting > 5V there, I'd say that's likely fine.

But if you have an original (unrecapped) PSU anyway, you're asking for other trouble anyway as the ripple or drift could be criminal.

BW

[VadimK]

Of course the best place to measure is the 5V and GND jumper just below the 030 on the DFB1X board itself.

If you're getting > 5V there, I'd say that's likely fine.

But if you have an original (unrecapped) PSU anyway, you're asking for other trouble anyway as the ripple or drift could be criminal.

BW

Thanks for the tip.

My first measurement was in PSU connector and it was just above 5V. On jumper below 030 there is only 3.3V!