Apple Pi

Just a quick video to show the disk emulator in action. SD card support is still in the works, so I'm just switching between three images embedded in the kernel.

The disk emulation is finally implemented! It was a nightmare to emulate everything from stepper motor magnets to the byte encoding, but now it loads .DSK images without problems and runs games and demos.

The disk controller emulation is not yet in place, but I cheated a little and injected a program into the Apple Pi's memory anyway and got an old cracktro running.  I also compared the results with another commercial emulator named Virtual ][, and the results were more or less identical.

The next goal is to finish the disk controller emulation, and then start playing with libcsud to see if I can get an USB keyboard working.

A speaker has been implemented and now plays the square waves generated by the CPU.   I can tell by the sound and the pitch of it that it's not perfect, but it's something I'll work on.  The speaker is controlled by the CPU toggling one GPIO pin via the $c030 register.  Think of it as manual PWM.

I also added an on-screen menu display.  Not all menu items are implemented yet, but F1, F3 and F12 works.  Disk support is still in the works.

Just for fun, I tested the emulator with an Apple ][+ ROM today.  No compatibility issues, works like a dream.