>1)programmable registers
The 6502 had (3):
A - Accumulator, 8 bits
X - Index 1, 8 bits
Y - Index 2, 8 bits
>2)jump and call instructions
The 6502 had only
JSR (absolute 16 bit)
JMP (absolute 16 bit)
JMP (indirect 16 bit - i.e. absolute 16 bit address is used as the location to read the target location from)
There were also the Branch-on instructions, all relative signed 8-bit:
BMI (minus)
BPL (plus)
BVC (overflow clear)
BVS (overflow set)
BCC (carry clear)
BCS (carry set)
BNE (not equal)
BEQ (equal)
And, not quite "instructions", the 6502 processor had a single interrupt line with a hard-coded vector, and a single non-maskable interrupt with a hard-coded vector.
>3)addressing modes.
These were:
zp = $00 Zero Page
zpx = $00,X Zero page, indexed
zpy = $00,Y
izx = ($00,X) Zero page, indirect (final address read in from target + x)
izy = ($00),Y Zero page, indirect (final address from target read in, then y added)
abs = $0000 Absolute
abx = $0000,X Absolute plus X
aby = $0000,Y Absolute plus Y
ind = ($0000) Indirect (final address read in from target)
rel = $0000 (PC-relative)
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