The new computer had a one-plus-one
addressing scheme,
in which each machine instruction,
in addition to the operation code
and the address of the needed operand,
had a second address that indicated where, on the revolving drum,
the next instruction was located.
In modern parlance,
every single instruction was followed by a GO TO!
Put *that* in Pascal's pipe and smoke it.
The Apple II floppy disk drive controller had a piece of "logic state sequencer" which was programmed this way: each instruction contained the address of the next one.
Or rather, something like this: the ROM is 256 bytes arranged as 16x16. Half of each byte is an opcode, and the other half is the row of the next instruction 0 to 15. The column is determined by some external inputs to the sequencer, representing state of the hardware.
Or rather, something like this: the ROM is 256 bytes arranged as 16x16. Half of each byte is an opcode, and the other half is the row of the next instruction 0 to 15. The column is determined by some external inputs to the sequencer, representing state of the hardware.
See https://archive.org/details/understanding_the_apple_ii (sec 9-14).