castleberrysam

16 registers
R0-R15
R0: program counter
R1: stack pointer
R15: link register

PUSH R           0000rrrr
CALL R, C        1001rrrr cccccccc cccccccc
POP  R           0001rrrr

castleberrysam

All registers are 16 bits and are initialized to all zeros.
Registers: pc, sp, fp, ax, bx, cx, dx, ex
pc (000): program counter
sp (001): stack pointer
fp (010): frame pointer
ax (011): general purpose A
bx (100): general purpose B
cx (101): general purpose C
dx (110): general purpose D
ex (111): general purpose E