MOS 6510
More info
- Manufacturer
- MOS Technology
- Type
- 8-bit microprocessor
- Released
- 1982
- Predecessor
- MOS 6502
The processor inside the Commodore 64 — a 6502 with a built-in I/O port that let the machine swap out its own memory from under its feet.
The 6510 was essentially MOS Technology's 6502 with one addition: six extra control pins routed through an I/O port at addresses $0000–$0001. The C64 used it to bank ROM areas in and out, freeing the full 64 KB of RAM under the same addresses that KERNAL and BASIC normally occupied. The clock ran just under 1 MHz, held back by the VIC-II stealing memory cycles.
That very memory banking underpins much of the C64 demoscene's conjuring: by blanking the ROM out, code could place sprites and screen data where the system otherwise sat. The programmers knowing the 6510's odd cycle timings by heart is a precondition for the raster routines that drove the hardware to its breaking point.