Re: 6502 illegal opcodes questions

["sicklittlemonkey" <Nick.Westgate@gmail.com>]

(From Linards)
> Is it documented anywhere which of these opcodes have which cycle counts?

Without checking, they should be the same as the corresponding LDA
opcode with the relevant addressing mode.

(From Marcus)
> There are some discrepancies between the different info files floating around the net.

Yes, I've been collecting these, and collating the information for some
time.

> v3.0

BTW, there's a 3.1 version of this doc floating around.

(From Freddy!)
> DOP (NOP) [SKB]

(Also TOP)
These are badly named. I prefer NOP or RDM (read memory) or perhaps ADR
(address).

(From Freddy!)
> The argument has no significance.

Bzzt! Next contestant please. This puts an address on the bus. This
means you can touch softswitches and I/O locations with these commands.
(Hence my preference for a different mnemonic.) Yes, I know the above
commands are 2 bytes, but the C64 has its I/O regs at $0000, $0001, and
there are a handful of 3-byte NOP $XXXX opcodes which can be used for
this on the Apple II.

Cheers,
Nick.