# Uxn A stack-based VM, written in ANSI C. ## Build ``` cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn ``` ## Assembly Syntax - `:label`, a named offset - `+literal`, a numeric value - `.pointer`, pointer to a label ``` < comment > +01 < literal > [ 01 02 03 04 ] < block of literals > $01 < pointer8 > { 01 02 03 04 } < block of pointer8 > ~ff0f < pointer16 > ( ff00 ff01 ff02 ff03 ) < block of pointer16 > =const +ff :label ADD RTS ``` ## TODOs - Implement addressing - Implement 16 bits operations - Jumps should be relative - Catch overflow/underflow - Implement literals like `[2]`, and `[ 2 3 ]`. - Audo-detect literals length. - SDL Layer Emulator - Build PPU ## Refs https://code.9front.org/hg/plan9front/file/a7f9946e238f/sys/src/games/nes/cpu.c http://www.w3group.de/stable_glossar.html http://www.emulator101.com/6502-addressing-modes.html http://forth.works/8f0c04f616b6c34496eb2141785b4454 https://justinmeiners.github.io/lc3-vm/