Quigibo, I have confirmed that a faulty behavior displayed by DJ's Axe Tunnel game is traceable to a flaw in your DCS header generation. A problem was not visible in 6.3 beta or lower because of a lucky break with how flags were set when DCS handed over control. You're currently jumping into the middle of the header, like so:
Code:
Therefore, you should be jr'ing to $9dd9 instead of $9dc1, an offset of $18 or 24d. Cheers.
Code:
9d95: xor d
9d96: ret
9d97: jr $9dc1
[...header data...]
9dc1: ld b,c ;$41
9dc2: ld a,b ;$78
[...more header data...]
9dd9: set AppAutoScroll,(iy+someflags)
9ddd: ld hl,$a52c
[...more code...]