My test routine at present does not simulate initialization, I just put in numbers where necessary to get it to work. The first odd number is also treated diferently. It does not shift the shift registers. Maybe the first cycle or two, the shift registers do not shift. That would make it easy to load the shift registers and the output register from a register mask programmed to 214. On Wed, 11 Jul 2012, Rhialto wrote: > On Wed 11 Jul 2012 at 05:20:17 +0000, William Levak wrote: >> I don't see how the chip is initialized. We know the shift >> registers start with 214 in them. Also the output register. Since > > I was thinking that the output register, being 8 toggle flip-flops, > could simply be wired to use the not-Q outputs for the bits that start > out as 1. > > As for the shift registers, that would probably work differently; there > are D-flipflops with reset circuits (and presumably everything in the > 6702 is wired to the reset line), so I spuppose some of the bits in them > could be wired to reset to 1 instead of 0. > > There is something special about the number 214 though, since it also > occurs (ok, as 214 + 1) in the 6809 machine code routine. > > -Olaf. > -- > ___ Olaf 'Rhialto' Seibert -- There's no point being grown-up if you > \X/ rhialto/at/xs4all.nl -- can't be childish sometimes. -The 4th Doctor > > 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 2012-07-12 06:00:03
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