This is an experimental Machine Forth for the TI-99. It uses Forth-like syntax but is really an Assembler. Many of the words are just aliases of the Forth assembler in Camel99 Forth. Although the syntax looks like Forth the significant difference is that registers are referenced explicity for maximum performance. The data stack and return stack are still available to the programmer however.

This Assembler was created when comparing the performance on the Byte Magazine Sieve of Erasthones benchmark using conventional Forth and an 9900 Assembly language version. Camel99 Forth performed ten iterations in 120 seconds. Using a "just-in-time" compiler and a number of other optimizations the fastest speed I could achieve with Forth was 38 seconds.

A C program compiled with GCC clocked in at 13 seconds. An Assembly language version of program did the same job in 10 seconds.

So the stack VM paradigm just adds too many instructions to really fly on the old 9900. When each instruction can use 14 to 28 clock cycles, every extra instruction is a killer.

See the demo folder for an example of the sieve benchmark in Camel99 Forth and in ASMForth. The ASMForth version runs in 9.25 seconds.

• Used like a Forth Assembler but with Forth-like syntax
• Seamless integration with the Camel99 Forth environment
• Up to 12X speed-up over threaded Forth
• Nestable sub-routines created with ASMForth versions of : and ;
• Tail-call optimization
  • In the spirit of Moore's machine Forth this is manually invoked using -;

We need the ability to create standalone binary programs.