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> Assuming 32 bit instructions You don't have to assume, the article itself says the author is contemplating 9-bit instructions.
by prutschman 12y ago
> Assuming 32 bit instructions
You don't have to assume, the article itself says the author is contemplating 9-bit instructions.
- danbruc 12y agoI did not read it like that. 9 bit is not really enough for an interesting instruction set for a register machine. It is however enough for a stack machine or something similar with implicit operands, but then again you need more instructions for the same task than with a register machine.
- prutschman 12y agoIf you search for the phrase "To add more 'regular' instructions" in part 1, you'll see where he references 8 or 9 bit instructions. The author goes on, in subsequent sections, to expand the idea of tokenized jump references to tokenized instructions. Each instruction token may only be 8 or 9 bits, but the secondary memory which contains jump targets is expanded to also contain full-width instructions. The operating hypothesis is that just it's desirable to be able to "reach" any 32-bit destination address despite any given code segment not needing that flexibility, it's likewise desirable to be able to execute any, say, 36-bit instruction even though any given code segment only needs a subset of them. It's really worth a read.