exxos's Atari, Amiga & retro forum

Yes, the Lightning ST provides such a solution with nicely 3D printed brackets for the USB ports, but since (if everything goes as expected...) the ET4000 VGA will be in the way, I have to find another place.

I personally do not like to heavily modify the aesthetics of my retro machines and try to keep as much as possible the original looks (the real power hides inside the inoffensive looking "beast"...). :)

Received a 40 Mhz oscillator today and tried it.

Result: worst than the 50 Mhz one.

Could not get to the desktop, random bombs and the FDD was making a freaky noise...

Quite weird.

Darklord wrote: 21 Dec 2021 03:17 Congratulations on getting your "mega" project to this point. :)

I put the USB ports in the expansion cover on the back of the
Mega ST for my Lightning ST setup. Dead handy.

I suppose it would be much more convenient and accessible
if one could have them in the front casing but I was afraid
that I would mar the looks of my machine...

Mega ST4-Lighnting ST01.JPG

You could always get a Gotek on a 3d printed mount and add USB to the front.

Like this one...

HigashiJun wrote: 21 Dec 2021 03:29 Yes, the Lightning ST provides such a solution with nicely 3D printed brackets for the USB ports, but since (if everything goes as expected...) the ET4000 VGA will be in the way, I have to find another place.

I personally do not like to heavily modify the aesthetics of my retro machines and try to keep as much as possible the original looks (the real power hides inside the inoffensive looking "beast"...). :)

Well....mine is in the back, but since you're using a video card you don't have much choice. - so I fully understand what you're saying. :)

I have finally received today the 4 layers CPU relocator PCBs from China.


This relocator was initially designed for the Amiga, but as our machines share the same CPU, it is not an issue.

Once the DIL socket and headers soldered, everything was fitted back in the Mega ST.


Since this new relocator is 4 layers and is shorter than the previous one, I hoped I would not have any quirks but I was totally wrong...

Issues are completely different, and the only way to have a stable machine is to fit the PAK68 directly in the CPU socket on the motherboard, at least in my Mega ST.

:(

It might be a 8mhz clock issue ? I had no end of trouble with it. I never got my PAK to work in any of my machines anyway :roll:

What were the inner copper planes? Both ground or one power and one ground?

HigashiJun wrote: 30 Dec 2021 06:51 Issues are completely different, and the only way to have a stable machine is to fit the PAK68 directly in the CPU socket on the motherboard, at least in my Mega ST.

Sorry, I haven't followed this thread. Did you solder multiple additional ground (and possibly also +5 V) connections from the PAK to the mainboard? As short as possible and made from thick wire, as described in the PAK manual? In my experience, the PAK3 is one of the least troublesome accelerators.

@stephen_usher

Seems weird, but I have just check the Gerbers and there is no connections for GND and VCC...

@czietz

My PAK has just 2 spots for GND and VCC. 2 thick wires are connected to GND and 1 thick wire is connected to VCC.

The PAK itself works, but when combined with a CPU relocator, I have issues with the FDD and the STVGA or VOFA.

@exxos

I will perform other tests, and if there are no results, I guess I will have to give up...