But the amount of memory a processor can handle is determined by its address bus, not the size of integers it uses.
42.
Only 24 pins were connected to the address bus, therefore limiting addressing to but this was not a critical constraint at the time.
43.
Like the 6800, it included an undocumented address bus test instruction which came to be nicknamed Halt and Catch Fire ( HCF ).
44.
As the PPU has a 14-bit address bus, it can access up to 16k of CHR ROM or RAM at once.
45.
Memory banking where blocks of memory could be switched in or out to a degree bypassed the restrictions of a 16 bit address buss.
46.
The 8087 and 80187 coprocessors are connected in parallel with the data and address buses of their parent processor and directly execute instructions intended for them.
47.
The Z80 processor used in the Spectrum has a 16-bit address bus, which means only 64 KB of memory can be directly addressed.
48.
The Intel 8086, the predecessor to the 286, was originally designed with a 20-bit address bus for its add-on devices.
49.
The intel 80286 had a 24-bit address bus and was able to address up to 16 RAM, compared to 1 MB for its predecessor.
50.
The 6800 has a 16-bit address bus that could directly access 64 KB of memory and an 8-bit bi-directional data bus.
