Projects

01 in development

TempleOS in Web Browser

Running TempleOS in a browser tab by emulating, piece by piece, the PC it was written for.

1. the target
   TempleOS is the 64-bit operating system Terry A. Davis wrote, very nearly alone, over about a decade: kernel, compiler, editor and the HolyC language itself. Everything runs in ring 0 in a single address space, there is no networking, and the display is fixed at 640×480 in 16 colours. Those constraints keep the whole system small enough for one person to hold in their head. They also mean it expects plain, specific hardware and nothing else: a BIOS, a CD-ROM, the classic timer and interrupt chips, a PS/2 keyboard and VGA.
2. why a new emulator
   Most in-browser x86 emulators stop at 32-bit protected mode. TempleOS does not boot without 64-bit long mode, so the CPU has to go further than they do: real mode for the BIOS, protected mode, paging, then the switch into long mode through the model-specific registers the loader writes.
3. the cpu
   Written in Rust and compiled to WebAssembly with wasm-bindgen. Instruction decoding uses the iced-x86 crate; execution, segmentation, paging and the 16/32/64-bit register file are written for this project. A small test binary decodes the real boot sector bytes to check the executor against what the loader actually runs.
4. the machine
   Around the CPU sits the rest of a PC: the 8259 interrupt controller, the 8254 timer, the CMOS clock, a PS/2 keyboard controller, a serial port mirrored to an on-page console, PCI configuration space so the firmware can enumerate devices, an IDE controller serving the original 2017 ISO as an ATAPI CD-ROM, and VGA drawn to a canvas with an 8×16 font. SeaBIOS, the firmware used by QEMU, does the early boot.
5. where it is
   CPU and devices run under SeaBIOS. Next is carrying the TempleOS loader into the kernel and up to the blue-on-white desktop, then input and speed. The page has start, pause and step-a-thousand-instructions controls for exactly this stage.

stack

Rust · WebAssembly · wasm-bindgen · iced-x86 · SeaBIOS

machine

x86-64 CPU, PIC, PIT, CMOS, PS/2, UART, PCI, IDE/ATAPI, VGA

status

CPU and devices running; booting toward the desktop