10 ! 4380A Test Program
20 ! Do not use TAB, only spaces
30 ! Working June 17, 2003
40 PRINTER IS PRT ! sets external printer in 4395A
50 COM @Na
60 Src=0
70 ASSIGN @Na TO 800   ! 4395A in internal Ibasic
80 Loop:LOOP
90 ON KEY 1 LABEL "Source" GOTO Inc_src
100 END LOOP 
110 STOP
120 Func=0    ! Cal Port
130 Mode=1   ! Open
140 Inc_src: ! Add 1 to Src roll over 7 -> 0
150 Src=Src+1
160 IF Src=8 THEN Src=0
170 Func=1
180 Mode=Src
190 PRINTER IS 1
200 PRINT "Func, Mode = ";Func,Mode
210 CALL Bpo(Func,Mode)
220 GOTO Loop
230 END
240 !
250 SUB Bpo(Func,Mode)
260 COM @Na
270 Portdata=Func*16+BINAND(Mode,15)
280 OUTPUT @Na;"OUT8IO ";128+32+16
290 OUTPUT @Na;"OUT8IO ";128+Portdata
300 OUTPUT @Na;"OUT8IO ";Portdata
310 OUTPUT @Na;"OUT8IO ";128+32+16
320 SUBEND !