VTL

VTL is an esoteric programming language created by David Catt (user:David.werecat) which loads code into modifiable memory and an extended section.

Instructions
Each instruction is split into two parts, the OpCode and the Param. The OpCode is the first three bits of the instruction, and the Param is the other 5 bits. Code is executed in a 256 byte long segment. There is a pointer register that points into that segment. The current "value" is the instruction pointed to by the pointer register. If a second file is specified to the interpreter, it is loaded into the extended section. The extended section can be any size. When execution flow jumps to the extended section, the pointer register still indexes the code segment. When the execution reaches the end of the code segment or extended section, it loops back to the start. Possible OpCodes are as follows:

Extended Instructions are as follows:

External resources

 * Visual Basic .NET interpreter and sample programs