On the cover of the classic Advanced User Guide (for the BBC Micro) by Bray, Dickens, and Holmes, we find this:



Or, in letters:

You'll notice 6 mnemonics interleaved. Are there more ways to do this? Many more, or just one or two? Is it easy to find them? Fancy writing a program to find them all??

Here's a bit of whitespace, just in case there are spoilers below.

.
..
.
...
.
..
.
....
.
..
.
...
.
..
.

Challenge accepted. I'll be back.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

There are more than you'd expect. Results in the two trace files (in the zip) for the 6502 and 65C02.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

That was quick! Well done! And not so very many - but enough to be interesting - with 6 distinct opcodes.

Its a quiet day in the code mine.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Now I'm imagining you chiselling code onto stone tablets...

Some days it feels like that.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

If we insist on six different instructions and ignore transposition, there are only two solutions. The second isn't hard to find, given the first.

Respect to whoever came up with that design.