From: Daniel Kahlin (tlr_at_stacken.kth.se)
Date: 2008-09-17 12:59:14
Hi On Wed, 17 Sep 2008 ruud.baltissen@apg.nl wrote: > Some questions: > - did anyone notice this, IMHO weird, use of the Q and E outputs before? > - how is this possible, I mean, two outputs connected together? > - are there 6809 experts amongst us? > - beside the well known "because it can be done", is there another > reason we benefit from a 6809 in a C64? (I was thinking about the FLEX > OS) There is a difference between 6809E and 6809. In the 6809E Q and E are inputs. If I remember correctly, only the 6809E allows the data/addr bus to be tri-stated. data sheet: http://koti.mbnet.fi/~atjs/mc6809/Information/6809Data.pdf some info here: http://www.bradrodriguez.com/papers/6809cpu.htm Regards /Daniel Message was sent through the cbm-hackers mailing list
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