I started for fun, a SI emulator, and got stuck at probably one stupid cpu, or flags bug.
I have working inputs, the game boots perfectly, shift registers are emulated, but when all the aliens are shown, the game makes a jump HL() instruction to what was on the stack, which is 0000, and resets itself obviously.
Here's the complete disassembled code:http://www.computerarcheology.com/Arcad ... /Code.html
The problem happens at PC: 0550
HL is set to 0x2073, then the copy block function is called, which copies 2073 and 2074 with 00, and those 00 are later feeding the HL register from stack, and making that invalid jump.
Any idea of what is going on ? I know is hard to find the problem, but I've seen it in other forums (with no replies).