+/*
+ * Prototype toggle in bootstrap code for ts type tapes.
+ * If on anything but a 780 with the drive on uba0
+ * this will have to be repaired by patching uba and umem.
+ */
+ .set UBA0,0x20006000
+ .set UMEM0,0x2013e000
+ .set UBA_MAP,0x800
+ .set TSADDR,0772520-0760000
+
+start:
+ movl uba,r10
+ movl mrv,UBA_MAP(r10)
+ addl3 mrv,$1,UBA_MAP+4(r10)
+ addl3 umem,$TSADDR,r11
+ clrw 2(r11)
+1: tstb 2(r11)
+ bgeq 1b
+ movw $0x200+setchr,(r11)
+1: tstb 2(r11)
+ bgeq 1b
+ movw $0x200+read,(r11)
+ halt
+ .align 2
+uba: .long UBA0
+umem: .long UMEM0
+mrv: .long 0x80000000
+setchr: .word 0xc004,0x200+char,0,0x8 # set characteristics command
+char: .word 0x200+status,0,0xe,0 # characteristics
+read: .word 0xc001,0,0,0x200 # read command
+status: