.ABSOLUTE
 .=600
.
;SET DESTINATION
 MOVB #71.,@#764052
 MOV #0,R2  ;DISC ADDRESS REG
 MOV #256,R3  ;NO OF TRACKS
 MOV #17440,R4  ;DL STAUS REG
;READ BLOCK
LOOP: MOV #1000,@#174402  ;BUFFER ADDRESS
 MOV R2,@#174404  ;DISC ADDRESS
 MOV #-5120.,@#174406  ;WORD COUNT
 MOV #14,(R4)  ;OFF WE GO
;WAIT TILL CONTROLLER READY
L1: TSTB (R4)
 BPL L1
 TST (R4)
 BGE L2
 HALT
L2: MOV #5120.,R0  ;STUFF IT DOWN THE RING
 MOV #1000,R1
L3: MOV (R1),@#764050
 ;WAIT TILL TRANSMITTER READY
L4: BIT #200,@#764056
 BEQ L4
;CHECK IF IT WAS ACCEPTED
 BIT #4,@#164046
 BNE L3  ;SEND IT AGAIN
 ADD #2,R1  ;BUMP BUFFER POINTER
 DEC R0  ;SEE IF ALL GONE
 BGT L3
 DEC R3  ;SEE IF DISC FINISHED
 BEQ L5
 ADD #20,R2  ;SEEK TO NEXT CYL
 MOV #204,@#174404  ;DISC ADDRESS REG
 MOV #6,(R4)  ;DO SEEK
L6: TSTB (R4)  ;SEE IF CONTROLLER READY
 BPL L6  ;NO
L7: BIT #1,(R4)  ;WAIT TILL DRIVE READY
 BEQ L7
 JMP LOOP
L5: HALT
 .END