Maybee the lack of of operands has something to do with the assembler. An operand is probably placed in the actual instruction.
It seems highly likly that the chip ran a program. It put out the number I instructed it to, only in hexidecimal instead of binary. In binary it was 0101 01010. Something like that.
It seem's that no interupt handlers are neccesary in a simple program. My prevous problems may have been due to voltage damage.
A different 8515? is being used now.
Martin