-I will now assume that 0x7000 is not mapped for the sake of continuing on. I will need to implement a mapper system shortly though.
--Did the same thing for 0x4800.
-AND@, MOVR, CMP enabled.
-Made the logging separator generate before an instruction instead of after the register states. This is quite petty, but I don't like the separator at the end of the file.
I hit an infinite loop, and I'm very very certain it's happening because I don't have an interrupt system yet. Time to stop avoiding that!
-Separated cartridge logic into a separate ICart named Cartridge.cs.
-Made WriteMemory return a bool to match ICart.Write. It currently returns true if either the cart or the core responded.
TODO: Parse the vanilla Intellivision ROM, which will hopefully include the read / writability of the data segments. adelikat seems to think that I just need to send the bytes to $5000, but I'm not convinced.
-Made it so that the indirect ops other than MVO@ decrement R6 when it's the mem address. Indirect write means writing to a register apparently, so maybe the documentation don't contradict itself.
-Fixed my disassembly of branch; I wasn't thinking in hexadecimal. >_<
-Subtracted 1 from the negated offset when branching in reverse. The next op is "BNEQ $FFFC".
-Fixed the branching disassembly; the direction just negates the offset and the second parameter only belongs to BEXT. All of my sources contradict each other, but this seems sensible.
-Applied to the old Gameboy core. Why not? It at least fixes that annoying bug from before if we ever care to use it again.
-Both logs are now written to different files.
--It now just builds a strings and writes on finalization.
-Fixed up format strings.
-As RegisterPC already increments upon reading the third decle, I now just store PC as the return address for jumping instead of PC + 1.
-Retrieved the double bit from the swap / shift / rotate instructions in a more proper way.
TODO: Use more specific variables; most of them suck, and with these docs, I have better names for them.
-Disabled Intellicart hook for ReadMemory, which seemed to be interfering.
-Implemented MVO@.
-Several instructions are now executed in succession until it hits the unimplemented "XORR R5, R5".
I should probably refactor Disassemble and Execute to label registers as source / destination to avoid further confusion at some point. My disassembly might have the source / destination registers flipped as well.
-They both seem to work, but the operands for AND@ are both 0, so this seems fishy.
-I don't know for sure if AND@ executes cycles in the same way that MVI@ as the documentation isn't clear on this, but I assumed it did.
According to my disassembler, the first 5 instructions run on the Executive ROM are:
JSRD R5, $1026
MVI@ R7, R6
ADD@ R6, R1
JSR R5, $1A83
HLT
Considering that I hit a HLT, I figure something is going terribly wrong. Perhaps it has to do with my lack of an interrupt system?
-Added bytesToAdvance assignments to the relevant opcodes I added yesterday.
TODO: Implement more stuff in Execute and use the Executive ROM as a test case.
-Fixed disassembly for JMP:
--Now it uses the parameter pc, not RegisterPC.
--I was loading both the second and third value from the second's address.
--Casting the calculated addresses to bytes when addresses are 16-bit was a bad idea.
--Removed a closing parenthesis I accidentally stuck in the formatting.
It seems that I've gotten far enough to use the Executive ROM as a test case! Now to go instruction by instruction and see if they work as planned and hope this will all eventually make something.
-Fixed JMP disassembly; I need to return on an invalid opcode because I was breaking out of the inner switch statement, not both that and the outer one.
-Made all instructions in the executor, even implemented ones, throw exceptions. I will get rid of the exceptions as I test the instructions.
-Added instructions up to and including 0x57 to disassembly and executor.
-Implemented ADCR.
-Decoded all opcodes up to 0x23F.
TODO: Try vecna's idea of testing the instructions by running a game and implementing instructions as I need them...but first I'll need to implement loading of an Intellivision game.
-Definitions.
--Registers, Flags, TotalExecutedCycles, PendingCycles, ReadMemory, and WriteMemory.
-Execute.
--Implemented opcodes 0x001-0x027 with the exception of 0x004 and 0x005.
-Made it so that the log only opens when logging is true and that the file closes upon destruction.
--Still, BizHawk says that it can't open the file again when I load a game again. This is because the emulator class gets recreated without deleting the original one every time you load a game.
---adelikat convinced me not to care about this.
-Fixed the initial state of the GB CPU:
--It was setting AF to 0x01, not A. This is effectively setting F to 0x01, which gets overwritten later anyway.
--Two BIOS flags were used in different places; merging them gets the PC to start in the right place.
-By fixing the initial state, most of the log now matches up.
--The only differences are the VBA has some repeated records (Where all of the registers, including PC, are the same as the previous record) whereas BizHawk doesn't.
--This very well might be an issue with how I'm logging it
--Alternatively, it could be some kind of lagging mechanism.
--I'm not sure which version is even correct...VBA is far from accruate.
--All in all, considering that the vast majority of the diff comes out as the same, I think I fixed the biggest CPU related bug. Will investigate more later.
brandman211