> [Spectrum and IM 2] From your code I see you are using the same trick by
> placing interrupt vector in the ROM where all bytes are #FF and putting
> the opcode of the JR instruction (#18) at #FFFF which then takes byte
> #F3 (opcode of DI at address #0000) as relative jump offset of -13 and
> after: JR $-13 the program continues at 65524 (#FFF4).
That's 100% correct. I found this a very obvious and straightforward
approach, given the fact that the lower half of the IM 2 jump location is
provided by the ZX Spectrum's bus, which could be anything at that time.
Saves you a table of 256 useless Bytes in precious RAM.