> Hand assembly was actually a common practice until 16-bit processors made 
> this too troublesome; with at most 256 opcodes to remember (although the 
> 6809[1] had prefix opcodes that made the following opcode take on a 
> different meaning), many 8-bit assembly programmers were perfectly capable 
> of reading and writing the opcodes directly from/to a memory listing.

With a RISC 32-bit processor it was pretty easy too.  The instructions were 
all 32-bit and all laid out in a similar way (first 5 bits for the 
instruction code, next 3 for conditional flags, next 3 groups of 4 bits for 
which registers to use, etc.  The OS had a handy disassembly function 
though, where you passed it the 32-bit opcode and it returned a string of 
assembler, of course most programs/debuggers made use of this so you rarely 
needed to actually decipher the bits.

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