On Sun 05 Feb 2012 at 12:34:47 +0100, A.Fachat wrote: > I looked it up in the schematics, the dongle should be reachable from > the 6502 side, so it should be easier for us 6502 guys to test it, > compared to having to write 6809 code :-) That helps, since I don't have the 6809 assembler going yet in VICEs monitor, and the Waterloo monitor doesn't have one either (only disassembly). Things that are likely to be of interest, are such as - if you read out the location multiple times, do you get the same result, or does it vary? - if you wait longer before you read, do you still get the same value, or does it vary? In other words, does it depend on timing? Here is a super simplistic test for the first item: (C:$101e) d 1000 .C:1000 A9 00 LDA #$00 .C:1002 8D E0 EF STA $EFE0 .C:1005 AD E0 EF LDA $EFE0 .C:1008 8D 00 20 STA $2000 .C:100b AD E0 EF LDA $EFE0 .C:100e 8D 01 20 STA $2001 .C:1011 AD E0 EF LDA $EFE0 .C:1014 8D 02 20 STA $2002 .C:1017 AD E0 EF LDA $EFE0 .C:101a 8D 03 20 STA $2003 .C:101d 00 BRK For a simple test of question 2, stuff a bunch of NOPs between the store and the loads: (C:$1029) d 1000 .C:1000 A9 00 LDA #$00 .C:1002 8D E0 EF STA $EFE0 .C:1005 EA NOP .C:1006 EA NOP .C:1007 EA NOP .C:1008 EA NOP .C:1009 EA NOP .C:100a EA NOP .C:100b EA NOP .C:100c EA NOP .C:100d EA NOP .C:100e EA NOP .C:100f EA NOP .C:1010 AD E0 EF LDA $EFE0 .C:1013 8D 00 20 STA $2000 .C:1016 AD E0 EF LDA $EFE0 .C:1019 8D 01 20 STA $2001 .C:101c AD E0 EF LDA $EFE0 .C:101f 8D 02 20 STA $2002 .C:1022 AD E0 EF LDA $EFE0 .C:1025 8D 03 20 STA $2003 .C:1028 00 BRK Of course they are just extremely simple cases, even if both tests result in always the same output that doesn't prove that later reads will be the same. > André -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 listReceived on 2012-02-05 13:00:04
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