STAGE2 IS:

	STAGE2 is a versatile macro processor developed by William
	M. Waite.  Operating on a generalized pattern recognition principle,
	it can be used for language translation, textual data filtering,
	limited printer output formatting, batch file editing and other text
	processing applications.

FEATURES:

	Pattern matching
	Symbol table (storage and retrieval under user control)
	Symbol generator
	Integer arithmetic
	Arithmetic expression evaluator
	Scan controlled iteration (search for specific characters)
	Count controlled iteration
	Conditional and unconditional branching (skips)
	I/O channel control
	Limited output formatting
	Recursion
	Error traceback showing all macro calls

STRONG POINTS:

	Highly transportable

	Some applications are an order of magnitude simpler to implement
	with STAGE2 than with conventional algorithmic languages.

WEAK POINTS:

	A bit slow
	Uses lots of memory for large applications (language translation)
	Macro code is very cryptic in appearance

REFERENCES:

	STAGE2 is in the public domain and is documented by the author
	in the book:
		Implementing Software for Non-numeric Applications
		by W. M. Waite
		1973  Prentice Hall

	Chapter 9 and appendix A include STAGE2 user information, source
	listings and implementation directions.

	STAGE2 is also documented by the author in:
		"Communications of the ACM"
		Volume 13 / Number 7
		July 1970
		Pages 415-421

STAGE2 for CP/M:

	This 8080 implementation was accomplished by:
		Dick Curtiss
		843 NW 54th
		Seattle, Washington  98107
		(206) 784-8018
					and is in the public domain.

DEVIATIONS FROM THE VERSION DISTRIBUTED BY WAITE:

	Variable length lines for input and output (132 char max)
		Input lines
			Carriage return terminates
			Line feeds are ignored
			Nulls are ignored
			Deletes are ignored

		Output lines
			Carriage return and line feed on every line

	Channel 5 implemented for console input and output

IMPLEMENTATION LIMITATIONS:

	STAGE2 is modeled on an abstract machine called the FLUB machine.  FLUB
	stands for First Language Under Bootstrap.  The FLUB machine word is
	made up of three fields:
		Pointer field		16 bits in this CP/M implementation
		Value field		8 bits
		Flag field		8 bits (only two used)

	Since the value field is sometimes used to hold string length, strings
	are limited to 255 characters maximum.  Under some circumstances the
	value field is considered to be signed so that strings longer than
	127 characters may cause strange results, but NOT a crash.  STAGE2 
	seems to be extremely well protected against crashes.

	Since the pointer field is used for arithmetic operations, values are
	limited to the range -32767 to 32767.  -32768 causes trouble.

	Each character stored by STAGE2 takes 1 FLUB word or 4 bytes in this
	implementation.

CP/M VERSION AVAILABILITY:
	CP/M Users' Group
	1651 Third Avenue   
	New York, NY  10028

DISCLAIMER:

	)()!&(%$#"#"%!!$(%!##!(!$!!$=(00(!#=!! so there!
	Use it at your own risk.

MORE INFORMATION:

	HELP.DOC	For the STAGE2 novice - start here

	USE.DOC		STAGE2 I/O summary and command line specification

	INTRO.DOC	Introduction to the STAGE2 processor

	IMPL.DOC	STAGE2 implementation notes

EXAMPLE FILES:

	ALX.S2M		Assembly Language eXtension translator macros
	ALX-.DOC	Notes on ALX.MAC

	ALXTEST.ALX	Test case for the ALX macros
	TERM.ALX	Sample program (incomplete)
	VDB.ALX		TDL video display driver for H19 emulation
	CIO.ALX		CP/M console I/O with PMMI modem in "parallel"

	MEMORY.INP	Macros and source for memory demonstration

	INTERACT.S2M	Macros to demonstrate interactive use of STAGE2

	DEMO.S2M	Macros for interactive exercise of most conversions
			and a few processor functions.  This is to be used
			while reading the INTRO.DOC file.

IMPLEMENTATION FILES:

	IOOP.SRC	Initialization and input/output package

	DISKIO2.SRC	General CP/M disk input/output package
	DISKIO2-.DOC	Documentation for above

	IOOP$.SUB	Submit file for creating IOOP.HEX

	FLT1.FLB	FLUB translation test program 1
	FLD1.DAT	Test data for FLT1

	FLT2.FLB	FLUB translation test program 2
	FLD2.DAT	Test data for FLT2

	STG2.FLB	Source program for STAGE2
	ST2T.DAT	Test data for STAGE2

	FLUB8080.S2M	STAGE2 macros for translating FLUB into 8080 code

	STG2SUP.ASM	Support routines for the FLUB machine

	STG2MATH.ASM	16 bit math routines for the FLUB machine

	FLUB$.SUB	Submit file for assembling FLT1, FLT2 or STG2