; -----------------------
; A sample PC 231 program illustrating some assembler features
; Fritz Ruehr # CS 231 # Fall 1998

; To test this file, try the command
;
;	asm231 < sample.asm

; -----------------------

	data	xFF	; lowercase gets fixed in output
			; hex constants start with "x"

	copy DR,R0	; use names for registers
	DATA 'A'	; ASCII characters in quotes
	copy DR,RA	; RA = J0 (synonyms for registers)
	DATA #label	; use labels; generates double hex

	READ R1,d0	; device numbers
	READ r2,AD	; AD = ASCII device;
			; also HD = hex device
			; and DD = decimal device

	JPIF R0,NZ,J0	; use of condition codes
#label
	INC DR,5	; can use pos/neg numbers for INC
	SHIFT DR,-1	; ditto for SHIFT (bug fixed!)
	HALT		; 
	
	CONST xA0	; CONST pseudo-instruction just 
			; places its argument in RAM
	CONST 'Z'	; useful for ASCII characters
	CONST -17	; negative numbers (decimal only)

; Comments from start of line are preserved in hex dump
; For hex dump, call as:

;	asm231 hex < sample.asm

; --------------------------
; End of sample program file
; --------------------------