It's been a standard feature of RT-11 FB since it first came out (in V2). You
need to set the select switch to display the "Display" register (unlike most
other OS idle patterns which rely on the data path display showing R0 when at a
WAIT instruction.
Here's what it looked like in V2.0 rmonfb.mac:
; "A SOURCE OF INNOCENT MERRIMENT!"
; - W.S. GILBERT, "MIKADO"
; "DID NOTHING IN PARTICULAR, AND DID IT VERY WELL"
; - W.S. GILBERT, "IOLANTHE"
; "TO BE IDLE IS THE ULTIMATE PURPOSE OF THE BUSY"
; - SAMUEL JOHNSON, "THE IDLER"
10$: DEC (PC)+ ;THE RT-11 LIGHTS ROUTINE!
20$: 1
BNE 14$ ;NOT TOO OFTEN
ADD #512.,20$ ;RESET COUNT, CLEAR CARRY
16$: ROL 13$ ;JUGGLE THE LIGHTS
BNE 11$ ;NOT CLEAR YET
COM 13$ ;TURN ON LIGHTS, SET CARRY
11$: BCC 12$ ;NOTHING FELL OFF, KEEP MOVING
ADD #100,16$ ;REVERSE DIRECTION
BIC #200,16$ ;ROL/ROR FLIP
12$: MOV (PC)+,@(PC)+ ;PUT IN LIGHTS
13$: .WORD 0,SR
14$: MOVB #MXJNUM/2+200,INTACT ;DO A COMPLETE SCAN
EXUSLK: BR EXUSER ;BACK INTO LOOKFOR LOOP
paul
> On Dec 27, 2017, at 11:03 AM, william degnan via cctalk
> <cctalk@classiccmp.org> wrote:
>
> Do you have an octal or asm listing for the part of the code with the
> migrating bar effect? This would be a good practice / test for me to try
> on my RT 11 system. Merry Christmas
> Bill
