The game of trying to count distinct instructions is, I suppose, innocuous; but doing so serves no good purpose. The PROP treats MVI, MVIY, and MVC as variants of a generic MOVE instruction; but it treats MVCLIN and MVCL as distinct instructions. There is, I believe, a hardware, instruction-implementation rationale for this distinction, but there is no functional one. Or again, as Tony Harminc has just pointed out, the mnemonic pair SIO, SIOF may be counted as one instruction or two. Examples of this sort can be multiplied ad nauseam by paging through the PROP. A count of distinct instruction mnemonics at time t--They are in an HLASM table having defined content at time t--can be precise. A count of instructions cannot. Qualitatively, it can be said that there are many more instructions than there once were; and that is enough. John Gilmore Ashland, MA 01721-1817 USA
