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. That's what I was referring to. A good ground connection in particular is required to reduce ground bounce. I know, but you only need to add a schmitt buffer to the CPU 8MHz clock reall...

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...

PS: of course the ultimate irony now that I have a stable product is that BOOTSTRA.TOS, the Linux kernel loader, hangs on reset with my board enabled. I vaguely recall a similar effect on my TT when running Linux. Iirc, I ended up loading the kernel to ST -RAM, via the "-s" argument to BO...

Fixed with this EmuTOS snapshot 20211203-115515-0b57c787 (or any later version), available at https://sourceforge.net/projects/emutos/files/snapshots/. Note that this fractal program, while not a GEM application, still uses AES functions and as such does not run from the EmuTOS early console. (The o...

I had assumed it was in the documentation. Then there is: http://fiebelkorn.net/email.jpg.

I assume you already tried contacting the author, Dieter Fiebelkorn? His website is still up and he writes there that he'll give out free registration keys to everyone who asks nicely.

Moving a rectangle on-screen is so much more than a memory copy! It involves masking and bit shifting. Imagine moving the rectangle by one pixel. Then bit0 needs to be shifted into bit1, bit1 into bit2, etc. Shifts are terribly slow on the 68000. That is precisely what I was saying: "The Blitte...

Actually, when doing a simple memcopy, the Blitter is only slightly faster - and not twice as fast. With the 68000, copying 32 bits with the CPU with "MOVE.L (Ax)+,(Ay)+" takes 20 cycles, i.e., 5 cycles per byte. Whereas copying 16 bits with the Blitter (neglecting the time to setup the Bl...

Blitter can't read from or write to ST-RAM faster than the CPU. All ST-RAM access is orchestrated by the MCU.

PS: If you want to test my hypothesis, you can use thorsten.otto 's inofficial but excellent custom EmuTOS building service: http://tho-otto.de/emutos/. Select "Output: emutos.prg" at the top, leave all options as they are except for disabling "3D Objects" and click on "Crea...