College: Rick - Macro Class

The MACRO class was much more interesting. MACRO is a computer language of sorts. In languages like FORTRAN and BASIC, you have commands like PRINT or LET, each of which causes a series of machine instructions to be executed. The PRINT command, for example, causes several hundred to several thousand instructions to be executed.

In MACRO, you code each machine instruction individually. So to PRINT something, you have to write hundreds of commands. Fortunately, you can create libraries of these sets of instructions, so you don’t have to rewrite those lines of code each time you want to print something.

You can do just about anything in MACRO, which is one of the things that appealed to me. Also, because MACRO is much closer to the machine, I learned quite a bit more about programming and hardware concepts than I did with FORTRAN or BASIC.

Rick was my MACRO teacher. He is a very imposing man … in stocking feet Rick stood six feet, eleven inches tall. He towered over everyone, and his booming, cheerful voice could be easy heard throughout the class.

Rick was a fascinating teacher. He basically taught one class a week in order to make some extra money while he was starting a new company. At the time, he called this company Systems Associates - he later renamed it to Software Techniques.

Before he was a teacher, Rick worked for Digital Equipment Corporation as a service representative. This meant when a customer had a program with a DEC machine, Rick was called to help them out. He was considered one of the best people in the department by just about everyone, including his direct supervisor, a man named Mike M.

Apparently Rick felt stifled at DEC, and decided to leave the company. He was well prepared - he walked out with a dozen or so customers. These customers were loyal to him, not DEC, not only because he was a good programmer, but because he could talk anyone into anything.

Rick’s lectures were great - he absolutely loved to talk. He could talk for hours and hours about practically anything, especially himself. He was very good at spicing up a dull lecture with personal anecdotes and remembrances.

The small program below is the first MACRO program that I wrote. All it does is load some numbers into memory and die with an error. The error just happens to print out the values previously placed in the memory locations.

	.TITLE        RICHARD LOWE, JR.
	.LIST         TTM
START:	MOV #3, R0
	MOV #4, R1
	ADD R0, R1
	HALT
	.END START

This is the second MACRO program that I wrote. It is similar to the first, except that it adds a bunch of numbers together. After that, it dies, printing the numbers out.

	.TITLE	RGL02	RICHARD G. LOWE, JR.
	.PSECT	RGL02
	.LIST	TTM
START:	MOV	#TABLE,R0
	CLR	R1		;INITIALIZE R1
AGAIN:	ADD	(R0)+,R1
	TST	(R0)
	BNE	AGAIN
	CALL	REGDMP
	EMT	46
TABLE:	.WORD	10.
	.WORD	17.
	.WORD	5
	.WORD	0
	.END	START

	.TITLE RGLO3 	MACHINE CODES FOR 41
	.=. + 500
	MOV	R0,R1
	MOV	(R0)+,R1
	MOV	-(R0),R1
	MOV	100(R0),R1
	MOV	#100,R1
	MOV	100,R1
	MOV	(R0),R1
	MOV	@(R0)+,R1
	MOV	@-(R0),R1
	MOV	@100(R0),R1
	MOV	@#100,R1

	.TITLE RGL04	MULTIECHO
	.PSECT RGL04
;
;     THIS PROGRAM WAS COPY-TYPED FROM THE BOOK.
;     IT WILL ECHO EACH TYPED IN CHARACTER N TIMES.  USE CIRCULAR
;     BUFFER OF 64 (DECIIMAL) BYTES FOR STORING AWAITING CHARACTERS.
;
	LC=.
	.=4+LC
	.WORD	6,0,12,0
	.=500+LC
START:	MOV	PC,SP		;
	TST	-(SP)		;     INITIALIZE SP TO START
;
KBSTAT=177560
KBDATA=177562
PRSTAT=177564
PRDATA=177566
;
	CLR	R0		;     INITIALIZE BUFFER INPUT POINTER
	CLR	R1		;     INITIALIZE BUFFER OUTPUT POINTER
	CLR	R2		;     INITIALIZE REPITITION COUNT
LOOP:	TSTB	KBSTAT		;     CHARACTER ENTERED?
	BPL	ECHO
	MOVB	KBDATA,BUFFER(R0)  ;  IF NOT, KEEP ECHOING
	INC	R0
	BIC	#177700,R0	;     ZERO R0 IF > 77
ECHO:	TST	R2		;     IF MULTIPLE ECHO TERMINATES,
	BEQ	NEXT		;     PREPARE FOR NEXT OUTPUT CHARACTER
	TSTB	PRSTAT		;     OTHERWISE PRINTER IS READY.
	BPL	LOOP		;     IF NOT, ACCEPT NEXT CHARACTER.
	MOVB	BUFFER(R1),PRDATA  ;  IF SO, ECHO NEXT CHARACTER.
	DEC	R2		;     (R2) = (R2) - 1
	BNE	LOOP		;     IF (R2) <> 0, ACCEPT NEXT CHARACTER.
	INC	R1		;     ELSE, (R1) = (R1) + 1
	BIC	#177700,R1	;     ZERO R1 IF > 77
NEXT:	CMP	R0,R1		;     IF (R0) = (R1) (BUFFER EMPTY),
	BEQ	LOOP		;     ACCEPT NEXT CHARACTER
	MOV	N,R2		;     (R2) = (N) (REPITITION COUNTER)
	BR	LOOP		;     ACCEPT NEXT CHARACTER
N:	.WORD	5
BUFFER:	.BLKB	64.
	.END	START
	EMT	46

	.Title  Error -- Error Handler Routines.
	.Psect	Error
	.Ident "X001AM"
	.Enabl	Lc
	.Dsabl	Gbl
	.Globl	Clrfqb
	.Globl	Regdmp
	.Globl	Print
;
;
;	E R R O R
;
;
;	Version X001AM
;
;	Written By: Richard Gerald Lowe, Jr.
;	Start Date: January 23, 1980
;
;	This module contains all of the subroutines to handle any
;	recoverable errors.
;
;
;
Error::
.Sbttl	Routine -- Print error text from system default error file.
;
;
;	Routine to print message from default error message file.
;
;	This routine is entered if no errors have been trapped so far.  They
;	are all fatal, and the program exits to the default Run-Time system.
;
;
Giveup:
	Movb	Firqb,Temp	; Push error code onto stack.
	Jsr	Pc, Clrfqb	; Clear out the firqb.
	Movb	#Errfq, Firqb + Fqfun	; Error message function number
	Movb	Temp, Firqb + Fqerno ; Put Error code into Firqb.
	Calfip				; Call the file Processor.
	Mov	#Firqb+Fqerno, R0	; Point R0 to beginning of text.
	Mov	#14., R1	; Set R1 for a maximum of 28. char.
	Mov	#Buff, R3	; Point R3 to buff.
	Clr	R2		; Set byte count to zero.
1$:	Tst	(R0)		; See if a character is here.
	Beq	2$		; No more characters, than we are at end
				;   of error message text.
	Mov	(R0)+,(R3)+	; Put Word of text into buff.
	Inc	(R2)+		; Increment text counter for another word.
	Sob	R1, 1$		; Get next Character.
2$:	Jsr	R5, Print	; Well, lets write out error message text.
	.Word	Buff		; Buffer position is in Firqb.
	.Byte 	0		; Channel 0
	.Byte	0		; Dummy variable.
	Mov	#14., R2		; Put length of fatal into R2
	Jsr	R5, Print	; Now, add the FATAL end of text.
	.Word	Fatal		; Position of buffer
	.Byte 	0		; Channel is 0
	.Byte 	0		; Dummy
	.Exit			; And, if we get here we cannot recover.
Buff:	.Blkb	30.		; Error message text is put here.
Fatal:	.Ascii	" -- FATAL" <13.><10.><7.><13.><10.>
Temp:	.Blkb	1.		; Temporary holding box.
	.Even
	.end

;
;	Routine to Input a string from KB:
;
;	Written By:  Richard G. Lowe
;
;	This routine merely inputs a one line string from the terminal.
;
.TITLE INPUT	Input
.PSECT INPUT
	Jsr	PC,SETXRB		;Jump to routine to clear XRB
	Mov	IBSIZ,(R0)+		;put buffer size in XRB
	Tst	(R0)+			;Skip the byte count
	Mov	#INBUF,(R0)+		;Pointer to I/O Buffer
	.Read
	Rts	Pc			;Return to calling program