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check scroll up opcode #68
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I don't know , It looks like it's the most complete set of manuals: |
LOL !!! sorry for cat link :) It has been mentioned in some emulators This is massive old manuals collection: Worth checking if it's widely used already |
It's been a while since I put together that doc with all the opcodes from different versions. I don't recall where I got the scroll up one from. |
Hello! So, I have investigated this issue to see if 00BN worked with the 199X era SCHIP 1.1 binary on an HP-48. I'm afraid to say that my result was a fairly conclusive 'no'. I have no reason to suspect there were later binaries created at current. I first created a test program in octo: http://johnearnest.github.io/Octo/index.html?gist=b0006a3aadb4cf43a0fb63aeb90fdece and simply ran this on the calculator, and it crashed out with result 538d, which I believe indicates that the PC hit the location of the mystery 00BN instruction and the program terminated. Following this, I actually tore apart the SCHIP 1.1 Binary via disassembly to locate the instruction handlers for these operations, which I can show you in... kind of simple form here:
You can follow each GOYES/GOTO to the following block of code. The prospective CHIP-8 instruction is tested for being either the 00E0 or EE command, then FF down through to FB. Finally, 00C? is tested, and then if the command was not any of those, the program terminates out. Our hopeful 00B? command has no code to handle it and, therefore, with it additionally not being included in the SCHIP 1.1 release notes, and so far as I'm aware, not included in any period roms, I think it is fairly safe to conclude that the command was not implemented on the HP48's super chip platform. I'm honestly not really sure why it wasn't though. The result though appears that there is not a 'correct' op code. |
Will do. Thanks. |
So the conclusion is: Thanks a lot! |
My own two cents: the first mention I found of |
Many manuals I could find on the internet mention that scroll up instruction has 00 BN form, but it looks that octo uses 00 DN form. Which is right opcode?
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