On Jun 13, 23:04, der Mouse wrote: [ ... ] Thanks for that, both. I actually have the reconstruction of the MACRO code: ;This is the MSCP bootstrap as listed in the RT-11 5.6 INS manual ... ; along with its disassembly (by hand!). Additional comments and ; attempts to make "nicer" assembly by ; Bob Schor bschor(a)vms.cis.pitt.edu (412) 647-2116 (w) ; ;Missing word (at 76102) and most of the explanation supplied by ; Jim Crapuchettes jimc(a)netcom.com 408-732-0569 ; .asect . = 42 .word 1000 ;-; Set stack pointer for RT-11 - don't "toggle" in . = 76000 ; The contents of R0 must be the MSCP unit number. Although it is set to 0 ; below, it could be manually set to some other value and then execution ; started at 76002. start: clr r0 ;76000/5000 ;; Preset register to 0 (unit) mov #172150, r1 ;76002/12701 ;; Point to IP register ;76004/172150 1$: mov #itabl, r4 ;76006/12704 ;; Point to init/cmd params ;76010/76156 mov #4000, r5 ;76012/12705 ;; Set init step to 1 ;76014/4000 ; Do 4-step controller initialization. Begin by writing any value to IP to ; reset the controller; all the rest of initialization is done through SA. mov r1, r2 ;76016/10102 ;; Copy IP address, write to mov r0, (r2)+ ;76020/10022 ;; IP to init & bump to SA 2$: tst (r2) ;76022/5712 ;; Test for error bit in SA bmi 1$ ;76024/100770 ;; Error = start init again bit (r2), r5 ;76026/31205 ;; Test step bit in SA br 3$ ;76030/401 ;; ????, appears to skip next bic (r1)+, (r5)+ ;76032/42125 ;; ????, seems to be skipped 3$: beq 2$ ;76034/1772 ;; Wait for next step ready mov -(r4),(r2) ;76036/14412 ;; Next init param to SA asl r5 ;76040/6305 ;; Move to next init step bpl 2$ ;76042/100367 ;; Loop thru 4 steps ; Bring unit on-line, read bootstrap (block 0) from the disk and start it up. 4$: tstb -(r4) ;76044/105744 ;; Point to next cmd byte bne 5$ ;76046/1002 ;; Loop thru commands mov pc, r4 ;76050/10704 ;; Point r4 to "clr pc" and clr pc ;76052/5007 ;; go start at location 0 5$: clr r2 ;76054/5002 ;; Init for clearing memory 6$: clr (r2)+ ;76056/5022 ;; Clear memory from loc 0 cmp r2, #17204 ;76060/20227 ;; thru loc 17202 ;76062/17204 blo 6$ ;76064/103774 ;; Loop until done incb @#17101 ;76066/105237 ;; Packet length = 400 bytes ;76070/17101 mov r0, @#17110 ;76072/10037 ;; Set unit number = 0 ;76074/17110 movb (r4), @#17114 ;76076/111437 ;; Move command to cmd pkt ;76100/17114 movb -(r4), @#17121 ;76102/114437 ;; Set parameter from table ;76104/17121 mov #17004, (r2)+ ;76106/12722 ;; Set response packet de- ;76110/17004 ;; scriptor: low 16 address mov r5, (r2)+ ;76112/10522 ;; bits & PortOwn bit mov #17104, (r2)+ ;76114/12722 ;; Set command packet de- ;76116/17104 ;; scriptor: low 16 address mov r5, (r2) ;76120/10512 ;; bits & PortOwn bit cmp -(r2),-(r2) ;76122/24242 ;; Point back to resp desc tst (r1) ;76124/5711 ;; Poll controller to start 7$: tst (r2) ;76126/5712 ;; Wait for resp desc PO bit bmi 7$ ;76130/100776 ;; => 0 == response received tst @#17016 ;76132/5737 ;; Status byte = success (0)? ;76134/17016 beq 4$ ;76136/1742 ;; Yes, go to next command stop: halt ;76140/0 ;; No, stop here... ; NOTE: This table MUST be - immediately preceeded by a zero byte (the HALT ; instruction) because it is the "end-of-table" marker; and immediately ; precede the Initialization Step Parameter table since a single register ; points first to the IStep Params (1 word each) and then to the commands ; (1 byte for the command, 1 byte for the parameter), passing through them ; in reverse. .byte 2 ;; Set byte count to 1000 for OP.RD .byte 41 ;; OP.RD = ReaD .byte 0 ;; 0 parameter for OP.ONL .byte 11 ;; OP.ONL = ON Line ;; .word 20402 ;76142/20402 ;; .word 4400 ;76144/4400 .word 1 ;76146/1 ;; IS4: GO bit .word 0 ;76150/0 ;; IS3: Ring base high address .word 17204 ;76152/17204 ;; IS2: Ring base low address .word 100000 ;76154/100000 ;; IS1: bits- ;; [15] = 1, [14] (WR) = 0, [13:11] (cmd ring ;; size) = 0, [10:8] (resp ring size) = 0, [7] ;; (IE) = 0, [6:0] (int vect/4) = 0 :: command ;; and response rings = 1 element, no inter- ;; rupts and no interrupt vector. itabl =: . ;need pointer to end of table ;76000g to start ODT .end stop ;For RT-11 only, don't "toggle" in IIRC, the wierdness at 076026 is because the original RT11 code was broken. Around 5.3 it got patched to work with the RQDX3 (which sometimes sets more than one bit in the SA). -- Pete Peter Turnbull Network Manager University of York