On Mon, 29 Aug 2011 23:29:06 -0400 "Justin R. Bendich" <[email protected]> wrote:
:>Do any of you old-timers (e.g. Fairchild, Cole) know how the EDIT (ED) :>instruction came to be the way it is? It's one of the original IBM 360 :>instructions. Has to be the most complicated of them. Did they have :>microcode back then? :> :>The main thing that bugs me about this instruction is that if you want :>leading zeroes, you have to add a "fix up" instruction at the end, or :>prepend an extra zero by means of the fill character. This is because :>the significance starter does not turn on the S-trigger for that byte. :>Also, the way the fill character is set, where it has to be the first :>byte, bugs me. You want a pattern plus leading zeroes? UNPK will work without. Also, if you set the fill character as zero you do not need an immediate significance starter. :>Why is it like that? It IS a useful instruction, but it's annoying. Its use is not meant for where you want all the leading zeroes. That is what UNPK is for. -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies.
