Emulate a screen

[thejpster]

If #3 used a host process to emulate a disk drive, it could also emulate a VGA screen. Periodically (say, 60 times a second), you'd fire an interrupt which dumped all 8 KiB of screen RAM over the UART to the host process. The host process would then interpret the contents of VRAM and draw to a GUI window, like the Neotron Desktop BIOS does.

Alternative options include:

• finding a QEMU machine which has native VGA output, but which also supports a Cortex-M CPU.
• using the Arm FVP for the Corstone-300, which apparently has VGA support.

[thejpster]

The lm3S6965 machine has OLED support - see https://www.freertos.org/cortex-m3-qemu-lm3S6965-demo.html. But it's only 128x64 pixels and that's not a valid Neotron mode.

[thejpster]

Or I could write a Cortex-M emulator and combine the QEMU BIOS with the Desktop BIOS.