I am having a hard time figuring out how to get the disassembler to run properly. Currently using M6811DIS. The issues I am having are addressing, load and entry points.

Bin in question is AUSJ, a 1227727 $A1 Bin. Appears to be a 27c256 chip and a 32kb Bin. When read with both APU1 and my old parallel port Pocket Programmer 2, I get a range of addresses from $0000-$7FFF. But reading around the older Source code threads, shows $FFFE as a potential entry point, but thats way out of my range of addresses? I assume I need to read file with a starting address of $8000 instead of $0000?

Second issue is with building a control file, best suited to work with this file. Assuming I leave it as $0000-$7FFF, I would use a load of 0000? Then the big issue is choosing an "entry point"??? I tried $7FFE and get a huge amount of blocks of .byte 0x00, 0xFF, etc. But only one opcode "suba" at the very bottom. Everything else is just a mass of "0xsomething, "

If don't use the reset vector as an entry point, how do I determine the entry point? This will help for sure, as I can try to use IDA Pro once I have an entry point. (Side question on IDA Pro, is which M68HC11 version do I pick? There are at least 50 variations, with some amount of EEPROM, RAM, ROM, etc.)

I just don't get this part. Since I didn't offset my bin, why doesn't $7FFE work? Am I creating an issue with off EPROM addresses by not reading with the offset? Is that why I cant get anything useful from a disassembly?

If anyone wants to take a look and offer some help, I'd appreciate it!

Bin, AUSJ.txt control file and initial disassembly(AUSJ DIS.txt) attached.

Thank you!
-Brett

 

What you are running into is the difference between the PROM physical address and the ECM virtual address. The PROM physical address range is from 0x0000 through 0x7FFF.

Once the PROM is placed into the ECM the address is offset by 0x8000 via the address decoding in the ECM. So the physical address of 0x0000 becomes 0x8000.

And the physical address of 0x7FFF becomes 0xFFFF in the virtual world of the ECM.

RBob.

 

Ok. Thank you! I will re-address the Bins.

so, I am working with a 1227727 AWRK 16k bin as well. Would that mean start at C000-FFFF?


what would a 16197427 $0D bin address out as? I think they are 64kb.

I am guessing then, that the “load XXXX” bit in the m6811dis disassembler is set to whatever the start value is in these cases, since I am disassembling the entire bin, and not a smaller section?

is there a standard entry point I should use? I’m new to this, so looking at hex is not gonna give me any clues yet... I’m not well versed at seeing code vs data...

thank you for your help!

 

Yes, the power up reset vector is near the end of the address space of the CPU.

The calibration starts at 0x4000. Below that is hardware access and RAM. In this case the entire PROM isn't used.

I can't help with that disassembler as I haven't used it. There should be a manual included with it for reference.

RBob.