Posted By
Gaia
on 2006-01-24
07:25:42
|  Re: XAA/ANE again
I have run Csabo's program yesterday on my plus/4 in screen blank mode and it gave identical results to those run with the screen on. So - at least for the sake of this small test program - the DMA seemingly has no effect. I got similar results to that of Ulysses's 4th and 5th plus/4 but it was depending on the initial value of the accumulator (on the contrary to what Csabos has said in the herein linked thread, there is no X -> AC operation). Note too, that the test program is by far not complete, we should theoretically test for all AC, X and immediate parameter combinations that is almost 17 million cases  Runtime is less of a problem but how shall we store the results?
Ulysses: I think your results were varying because of the different default values of the MONITOR register dumps (that have nothing to do with the real register values but rather what values are found at those RAM locations where the initial values are read from when issuing the G command in MONITOR). So if you could just make sure you test both with an AC value of a $00 and a $FF (by setting it via the R command) on all the different computers? But more importantly, we should make a better test program. Once such program is done, I guess we could indicate here which revision of the 8501 processor is built into the machine for which the test program is run. But first a more sophisticated test program is necessary. Any volunteers maybe?
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