Lazer's Interactive Symbolic Assembler (
Lisa) is an interactive
MOS 6502The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
assembler for Apple II computers written by
Randall HydeRandall Hyde is best known as the author of The Art of Assembly Language, a popular book on assembly language programming. He created the Lisa assembler in the late 1970s and developed the High Level Assembly language....
in the late 1970s.
The latest version of Lisa is V3.2. Syntax mistakes can be reported immediately in the edit mode. Lisa can assemble about 30,000 lines of code in a minute on a 1 MHz computer.
Lisa, before v.3, was able to assemble
SWEET16SWEET16 is an interpreted "byte-code" language invented by Steve Wozniak and implemented as part of the Integer BASIC ROM in the Apple II computer...
codes, a virtual
16-bit-16-bit architecture:The HP BPC, introduced in 1975, was the world's first 16-bit microprocessor.Prominent 16-bit processors include the PDP-11, Intel 8086, Intel 80286 and the WDC 65C816...
processor implemented as part of the
Integer BASICInteger BASIC, written by Steve Wozniak, was the BASIC interpreter of the Apple I and original Apple II computers. Originally available on cassette, then included in ROM on the original Apple II computer at release in 1977, it was the first version of BASIC used by many early home computer owners....
.
Lazer's Interactive Symbolic Assembler (
Lisa) is an interactive
MOS 6502The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
assembler for Apple II computers written by
Randall HydeRandall Hyde is best known as the author of The Art of Assembly Language, a popular book on assembly language programming. He created the Lisa assembler in the late 1970s and developed the High Level Assembly language....
in the late 1970s.
The latest version of Lisa is V3.2. Syntax mistakes can be reported immediately in the edit mode. Lisa can assemble about 30,000 lines of code in a minute on a 1 MHz computer.
Lisa, before v.3, was able to assemble
SWEET16SWEET16 is an interpreted "byte-code" language invented by Steve Wozniak and implemented as part of the Integer BASIC ROM in the Apple II computer...
codes, a virtual
16-bit-16-bit architecture:The HP BPC, introduced in 1975, was the world's first 16-bit microprocessor.Prominent 16-bit processors include the PDP-11, Intel 8086, Intel 80286 and the WDC 65C816...
processor implemented as part of the
Integer BASICInteger BASIC, written by Steve Wozniak, was the BASIC interpreter of the Apple I and original Apple II computers. Originally available on cassette, then included in ROM on the original Apple II computer at release in 1977, it was the first version of BASIC used by many early home computer owners....
. However, Apple II's integer ROM was replaced by Monitor ROM since Apple II+.
The assembler also features "Randy's Hi-res Routines", a set of
2D computer graphics2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
commands. Apple II's hi-res display pages (Hi-Res 1: 280 x 160 and Hi-Res 2: 280 x 192) were implemented by
Steve WozniakStephen Gary "Woz" Wozniak is an American computer engineer who founded Apple Computer, Inc. with Steve Jobs. His inventions and machines are credited with contributing significantly to the personal computer revolution of the 1970s. Wozniak created the Apple I and Apple II computers in...
using two
TTLTransistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...
chips. Therefore a software programmer has to deal with the discontinuous addressing of screen pixels (a full screen is split into three parts horizontally) and each pixel's coloring properties (each pixel uses 1-bit, its color is determined by that bit's place in a byte and its neighboring pixel). These ready-made
subroutineIn computer science, a subroutine or subprogram is a portion of code within a larger program, which performs a specific task and is relatively independent of the remaining code....
s were created to help programmers.
Lisa has a built-in
disassemblerA disassembler is a computer program that translates machine language into assembly language—the inverse operation to that of an assembler. A disassembler differs from a decompiler, which targets a high-level language rather than an assembly language...
.
External links