Hi Ruud! > 1- The datasheets say the BRK and COP instruction are 2 bytes long when > in native mode. Correct? Yup! > 2- (Only if answer for 1 = yes) When I look further the only thing > related to this second byte is a byte, called Signature, which is > read. The only thing I can imagine of this is that this byte can be > used for programmers to find out which BRK or COP has caused the SW- > interrupt. correct? Yup! > 3- (Only if answer for 1 = yes) Used in the emulation mode, the BRK > instruction only must be 1 byte long. But still PC seems to be > increased with 2 after the instruction: Actually, the 6510 one is also two bytes long. If you look at the BRK spec in e.g. the Programmer's Reference Guide, it pushes PC+2 onto the stack; similarly, if you look at e.g. the source code for Supermon it subtracts 2 from the PC counter on the stack to get the correct PC. > 4- JML = JuMp Long ($..) but the datasheet says it is "absolute > indirect". This means it has to be used like this: > > JML ($1234) > > causing the 65816 to fetch the three bytes from the address > $1234..$1236. Correct? Yup! Hey, this one was pretty easy -- three Yups and two sentences :) -Steve - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi.
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