Master 512 D86 Opcode Exception

[wisemoth]

I've been tinkering with my Master 512 today: I wanted to try the A86 and D86 programs (via cowsarenotpurple). While A86 runs OK, D86 aborts with an ESC Opcode Exception Error. I'm a bit puzzled because cowsarenotpurple says the package runs 'well' on the 512. I've tried with and without PCCE running.

As I can't use D86 to debug D86 I thought I'd see if anyone else has seen it working, or has found another assembler/disassembler that works on the 512.