byuu says:
Changelog:
- SMS: emulated the remaining 240 instructions in the (0xfd, 0xdd)
0xcb (displacement) (opcode) set
- 1/8th of these were "legal" instructions, and apparently games
use them a lot
- SMS: emulated the standard gamepad controllers
- reset button not emulated yet
The reset button is tricky. In every other case, reset is a hardware
thing that instantly reboots the entire machine.
But on the SMS, it's more like a gamepad button that's attached to the
front of the device. When you press it, it fires off a reset vector
interrupt and the gamepad polling routine lets you query the status of
the button.
Just having a reset option in the "Master System" hardware menu is not
sufficient to fully emulate the behavior. Even more annoying is that the
Game Gear doesn't have such a button, yet the core information structs
aren't flexible enough for the Master System to have it, and the Game
Gear to not have it, in the main menu. But that doesn't matter anyway,
since it won't work having it in the menu for the Master System.
So as a result, I'm going to have to have a new "input device" called
"Hardware" that has the "Reset" button listed under there. And for the
sake of consistency, I'm not sure if we should treat the other systems
the same way or not :/
byuu says:
Changelog:
- MS: added ms/bus
- Z80: implemented JP/JR/CP/DI/IM/IN instructions
- MD/VDP: added window layer emulation
- MD/controller/gamepad: fixed d2,d3 bits (Altered Beast requires
this)
The Z80 is definitely a lot nastier than the LR35902. There's a lot of
table duplication with HL→IX→IY; and two of them nest two levels deep
(eg FD CB xx xx), so the design may change as I implement more.
Tim Allen