According to that scheme, if I write 215, then the low order bit should change every 6 times, toggling between 214 and 215. That's exactly what happens. On Sat, 12 May 2012, Rob Clarke wrote: >> Writing 00100001 results in 11110111 and bit 4 now counts with a period of > 3. > > obviously I meant bit 5 here. > > On 12/05/2012 12:06, Rob Clarke wrote: >> 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. >>> >>> >>> wlevak@sdf.lonestar.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 list > > > Message was sent through the cbm-hackers mailing list > wlevak@sdf.lonestar.org SDF Public Access UNIX System - http://sdf.lonestar.org Message was sent through the cbm-hackers mailing listReceived on 2012-05-13 08:00:08
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