Looks to me like the seed value is EOR'd with the written odd value and only the counters for those bits are incremented. Given a seed of 214 - 11010110 Writing 00000001 results in 11010111 and bits 5 & 3 do not count. Writing 00000011 results in 11010101 and bit 5,3 & 1 do not count. Writing 00001001 results in 11011111 and bit 3 now counts with a period of 8. Writing 00100001 results in 11110111 and bit 4 now counts with a period of 3. Rob On 12/05/2012 10:42, William Levak wrote: > On Sat, 12 May 2012, William Levak wrote: > >> I don't think it very likely that a chip the size of a 6702 can do an >> actual divide. > > Not divisions; simple counting circuits, the intervals as Kajtar Zsolt > described. > > Starting number, 214 > > 128 toggled every 2 numbers > 64 toggled every 5 numbers > 16 toggled every number > 4 toggled every 7 numbers > 2 toggled every 3 numbers > 1 toggled every 6 numbers > > The pattern repeats every 420 numbers. (I neglected that 14 and 60 > have a common factor). > > Each operation affects only one bit, the whole chip would require 8 > counting circuits and perhaps a couple registers. The output would > require a latched register. > > This is from writing 0, followed by 1. Now that I have a formula, I > can test what other numbers might do. > > > firstname.lastname@example.org > SDF Public Access UNIX System - http://sdf.lonestar.org > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2012-05-12 11:00:10
Archive generated by hypermail 2.2.0.