If memory is very small is less instructions accessable. To handle this, will it need to be loaded a bootloader. The bootloader is saved into memory. These instruction need to be stored before the address is used. Address is stored from top, and the instructions that use 0100H to 0113H is not in 0000H to 0013H address room.
Operation depends on instruction at reset.
The bootloader is not critical to which value to store, and it is possible to change, modify, read etc. A15 is used to return with bit's from bootloader. As far as I see may the methode be used for a wide range of CPU's. The code, and the schematic, is attached to this document. Only the circuit schematic is needed.