VSK-E16A Emulator

An Overview

The VSK-E16A is a simple 16-bit emulator written in python.

Includes:

stack-based PMIO (see PMIO STACK)

64K Of word-addressed memory (see ADDRESSING)

256-word IVT (see Interrupts)

hardware interrupts (see Interrupts)

speed (iF 0): ~800khz max

speed (iF 1): ~200khz max

max speed is different based on HWI status as check_HWI_status() is taxing on performance

64K-word addressed 'disk' (see disk)

fully compatible with PyPy3

.vsix vscode extension for xasme16a syntax highlighting and hover explanations inside

much more in-depth (VIBE CODED!!!) .HTML manual inside

included full OS (ahoxOS) and official BIOS source

included boot.bat file (requires wezterm)

The assembler for xasme16a lives inside the emulator (see pre-run shell)

Pre-Run Shell The .py source includes a live shell upon pressing ctrl on startup. You can list commands using the help command

PMIO STACK The PMIO in this emulator is stack-based, each device shares a 255-word LIFO stack for communicating with devices

ADDRESSING Each address in disk and memory can hold a 16-bit unsigned variable. There is no byte-addressing or bit shifting.

Interrupts Hardware interrupts go through check_HWI_status which gets called every tick when iF is 1 (HWIs enabled) - if a interrupt is ready it will go through the DoHardwareInterrupt class.

NOTES Please note that:

1. This is not 100% bug-free. Not even close. Expect random bugs from time to time, but no known bugs cause the CPU to behave in a way that contradicts its intended design.
2. Some parts of the emulator are vibe coded (using claude). List of things made by AI here:
   • The debugger GUI
   • .HTML manual
   • Disassembler
3. This was never meant to be a publicly released project, therefore the paths are fixed to 'C:\python\VSK-E16A Workspace', but booting .img and imaging .xsm files outside of this dir are still supported.