xyw is an experimental register/stack virtual machine and assembler programmable using an assembly-like concatenative language. It is inspired by Uxn and by early assemblers targeting 8-bit CPUs like the MOS 6502, the Motorola 6809, and the Zilog Z80. IMPORTANT xyw v352-0 is currently a working prototype. The source code is available here. overview get-started examples lib kdds formats asm syntax directives notation vm instructions modes memory errors devices device-api todo