;These echo routines are taken from the MITS Basic 3.2 manual (1975)
;
;REV 0 SERIAL I/O BOARDS WITHOUT THE STATUS BIT MODIFICATION
;0	333	0xDB		IN	0x00
;1	000	0x00		
;2	346	0xE6		ANI	0x20
;3	040	0x20
;4	312	0xCA		JZ	0x0000
;5	000	0x00
;6	000	0x00
;7	333	0xDB		IN	0x01
;10	001	0x01
;11	323	0xD3		OUT	0x01
;12	001	0x01
;13	303	0xC3		JMP	0x0000
;14	000	0x00
;15	000	0x00

;FOR REV 1 SERIAL I/O BOARDS (AND REV 0 MODIFIED BOARDS) -> all switches down on the altair panel, 0x00 on device 255 (Basic 3.2)
;0	333	0xDB		IN	0x00
;1	000	0x00
;2	017	0x0F		RRC
;3	332	0xDA		JC	0x0000
;4	000	0x00
;5	000	0x00
;6	333	0xDB		IN	0x01
;7	001	0x01
;10	323	0xD3		OUT	0x01
;11	001	0x01
;12	303	0xC3		JMP	0x0000
;13	000	0x00
;14	000	0x00

.target "8080"
.format "bin"
.org 0

		IN	0x00
		RRC
		JC	0x0000
		IN	0x01
		OUT	0x01
		JMP	0x0000