David A.S.Crofts
	================

	23 Brisbane Street
	Berwick Victoria 3806
	Australia

	16th December 2003

	web:   http://members.iimetro.com.au/~crofts/david.htm

	email: dasc1961@netscape.net


The included CAS files represent the best of the programs I wrote on my old System 80
between 1980 and 1982. My System 80 was a clone of the TRS-80 Model I with LEVEL II BASIC 
and 16K RAM. I have tested these files in Windows using David Keil's Emulator running 
LEVEL II BASIC and 16K RAM. I have also tested these files in Linux using Timothy Mann's 
Emulator. I owe David Keil and Timothy Mann a debt of gratitude because in 2003 it was a 
real buzz to see my old programs again.


You can download David Keil's Windows Emulator from : http://discover-net.net/~dmkeil/

You can download Timothy Mann's Linux Emulator from : http://www.linux.org/apps/AppId_3541.html

Please note that Timothy Mann's Emulator requires a ROM image 
which you can get from David Keil's Emulator.



The following instructions assume that you have just started David Keil's
TRS-80 Model I Emulator with LEVEL II BASIC and 16K RAM.



SYS_SI.CAS	Machine Code Space Invaders  ( My Masterpiece !!!! )
==========	---------------------------

	Queue cassette at start using F11
	Type "SYSTEM"	Hit Enter
	Type "SI"	Hit Enter
	When tape loaded and next SYSTEM prompt appears Hit Break (Esc)
	Type "CLOAD"	Hit Enter
	When READY prompt appears Type "RUN" and Hit Enter.








SYS_PP.CAS	Machine Code Ping Pong
==========	----------------------

	Queue cassette at start using F11
	Type "SYSTEM"	Hit Enter
	Type "PP"	Hit Enter
	When tape loaded and next SYSTEM prompt appears Type "/" and Hit Enter








SYS_CC.CAS	Machine Code Calculator
==========	-----------------------

	Queue cassette at start using F11
	Type "SYSTEM"	Hit Enter
	Type "CC"	Hit Enter
	When tape loaded and next SYSTEM prompt appears Hit Break (Esc)
	Type "CLOAD"	Hit Enter
	When READY prompt appears Type "RUN" and Hit Enter.





	Calculator Instructions
	=======================


	Numbers		[-]nnn...[.nnn...][D/E[+/-]nn]
	-------
			eg: 1, -1, 0.333, -0.333, -1D10, 1D-10, -1E10, 1E-10 

	Constants	E, PI
	---------
			note:	E =  2.718281828459045235
				PI = 3.141592653589793238

	Operators	**, /, *, +, -
	---------
			note:	**  is to the power.
				operators are binding order.

	Functions	-, ABS, ATAN, COS, EXP, LOG2, LOG10, LOG, SIN, SQRT, TAN.
	---------
			eg: SQRT(SIN(PI/4)**2+COS(PI/4)**2), TAN(PI/4), -(-(1)), LOG(1/E/E)


	The Microsoft Assembler SYSTEM cassette, EDTASM.CAS, has been provided along with 
	calculator source file, LST_CC.CAS, for anyone who wants to add more functions



BAS_8Q.CAS	Basic Program to solve Eight Queens Problem
==========	-------------------------------------------

	Queue cassette at start using F11
	Type "CLOAD"	Hit Enter
	When READY prompt appears Type "RUN" and Hit Enter.

	Note:-	The Program expects that the solutions are saved after program so
		if you just want to display the solutions, leave tape queued and
		follow prompts in program.






BAS_OX.CAS	Basic Program to play unbeatable Noughts & Crosses  ( TicTacToe )
==========	--------------------------------------------------

	Queue cassette at start using F11
	Type "CLOAD"	Hit Enter
	When READY prompt appears Type "RUN" and Hit Enter.