New ZX81 Games

[dr beep]

If that ROM uses some sysvar that could be the problem.

I only allow
DFILE
LASTK
FRAMES and
CDFLAG

Rest is used as code

[siggi]

Which other of your games uses the same sysvars? I would like to check whether it runs on my ZXNU ..

[dr beep]

Which other of your games uses the same sysvars? I would like to check whether it runs on my ZXNU ..

Almost all. You could try CUBICMAZE (page 30), YAHTK (page 30) or LUNAPARK81 (on top of page 33)

[dr beep]

Latest version with option to do a CLS

[siggi]

Cubimaze works as expedted and does not crash ...

[dr beep]

Cubimaze works as expedted and does not crash ...

But GOL starts and creates a blanc inverted screen in 2 steps? First leaving corners, the clear corners?

If so then game loads ok. And then pressing a key (latest version NEWLINE/SPACE) gives the cursor?

And THEN setting a colony with Z gives a crash?

[siggi]

Cubimaze works as expedted and does not crash ...

But GOL starts and creates a blanc inverted screen in 2 steps?
First leaving corners,

Yes

the clear corners?

NO

If so then game loads ok. And then pressing a key (latest version NEWLINE/SPACE) gives the cursor?

And THEN setting a colony with Z gives a crash?

No cursor, no (visible) reaction on any key (except "Z"': crash)

AFAIK the Bigbang rom has a modified "CLS"-routine to clear an expanded screen faster (stores the state of the un/expanded screen in a bit in a system variable).
And the "scroll" routine is modified to not create a compressed line at the bottom of the screen.

[dr beep]

Well, I don't use CLS from the ROM.

Very weird that not even a cursor appears since that test is only reading LASTK.

So the game does create an inverse screen?

Make video of what happens. Then I can determine where it goes wrong.

[siggi]

Here it is ():
https://youtu.be/oL-BFEbadu8

[dr beep]

I see only 1 loop working properly (corners do not erase)
so somehow after the first loop the second is not run.
This is possible if LASTK is somehow effected.

It could be that LASTK is the sysvar used by the ROM.

Can I see the ROM somewhere?