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David Schmenk 2016-01-30 09:24:09 -08:00
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@ -4,7 +4,7 @@ PLASMA: **P**roto **L**anguage **A**s**S**e**M**bler for **A**pple
PLASMA is a medium level programming language targeting the 8-bit 6502 processor. Historically, there were simple languages developed in the early years of computers that improved on the tedium of assembly language programming while still being low level enough for system coding. Languages like B, FORTH, and PLASMA fall into this category.
PLASMA is a combination of virtual machine and assembler/compiler matched closely to the 6502 architecture. It is an attempt to satisfy a few challenges surrounding code size, efficient execution, small runtime and flexible code location. By architecting a unique bytecode that maps nearly one-to-one to the higher-level representation, the compiler/assembler can be very simple and execute quickly on the Apple II for a self-hosted environment. A modular approach provides for incremental development and code reuse. The syntax of the language is heavily influenced by assembly, Pascal, and C. The design philosophy was to be as simple as feasible while retaining flexibility and symantic clearity. You won't find any unnecessary or redundant syntax in PLASMA.
PLASMA is a combination of virtual machine and assembler/compiler matched closely to the 6502 architecture. It is an attempt to satisfy a few challenges surrounding code size, efficient execution, small runtime and flexible code location. By architecting a unique bytecode that maps nearly one-to-one to the higher-level representation, the compiler can be very simple and execute quickly on the Apple II for a self-hosted environment. A modular approach provides for incremental development and code reuse. The syntax of the language is heavily influenced by assembly, Pascal, and C. The design philosophy was to be as simple as feasible while retaining flexibility and symantic clarity. You won't find any unnecessary or redundant syntax in PLASMA.
Different projects have led to the architecture of PLASMA, most notably Apple Pascal, FORTH, and my own Java VM for the 6502: VM02. Each has tried to map a generic VM to the 6502 with varying levels of success. Apple Pascal, based on the USCD Pascal using the p-code interpreter, was a very powerful system and ran fast enough on the Apple II to be interactive but didn't win any speed contests. FORTH was the poster child for efficiency and obtuse syntax. Commonly referred to as a write only language, it was difficult to come up to speed as a developer, especially when using other's code. My own project in creating a Java VM for the Apple II uncovered the folly of shoehorning a large, 32-bit virtual memory environment into 8-bit, 64K hardware.