1 .title M9312 'MT' BOOT prom for TM11 controller 2 3 ; This source code is an exact copy of the DEC M9312 23-758A9 boot PROM. 4 ; 5 ; This boot PROM is for the TM11 controller with TS03/TU10/TE10 drives. 6 ; 7 ; Multiple units and/or CSR addresses are supported via different entry points. 8 ; 9 ; Standard devices are 82S131, Am27S13, 74S571 or other compatible bipolar 10 ; PROMs with a 512x4 TriState 16pin DIP architecture. This code resides in 11 ; the low half of the device; the top half is blank and unused. 12 ; 13 ; Alternatively, 82S129 compatible 256x4 TriState 16pin DIP devices can be 14 ; used, as the uppermost address line (hardwired low) is an active low chip 15 ; select (and will be correctly asserted low). 16 17 172520 tmcsr =172520 ; std TM11 csrbase 18 19 177776 tmcs =+0-2 ; status 20 000002 tmwc =+4-2 ; word count 21 22 165564 diags =165564 ; console diags phase2 entry 23 24 .asect 25 173000 .=173000 26 27 ; -------------------------------------------------- 28 29 173000 124 115 start: .ascii "TM" ; device code (reversed) 30 31 173002 000176 .word last-. ; offset to next boot header 32 33 173004 000261 mt0n: sec ; boot std csr, unit zero, no diags 34 173006 012700 000000 mt0d: mov #0,r0 ; boot std csr, unit zero, with diags 35 173012 012701 172522 mtNr: mov #tmcsr+2,r1 ; boot std csr, unit 36 173016 010704 mtNb: mov pc,r4 ; boot csr , unit 37 173020 103054 bcc diag ; br if diags requested 38 173022 000411 br go ; return to (R4)+2 from diags 39 ; then skip over pseudo reboot vector 40 41 ; -------------------------------------------------- 42 43 173024 173000 .word 173000 ; prom start addess @ 24 44 173026 000340 .word 340 ; and priority level @ 26 45 46 ; -------------------------------------------------- 47 48 173030 012700 000001 mt1d: mov #1,r0 ; boot std csr, unit one, with diags 49 173034 000766 br mtNr ; continue 50 51 173036 012700 000001 mt1n: mov #1,r0 ; boot std csr, unit one, no diags 52 173042 000261 sec ; no diag flag 53 173044 000762 br mtNr ; continue 54 55 ; -------------------------------------------------- 56 57 173046 010003 go: mov r0,r3 ; copy unit number 58 173050 000303 swab r3 ; to upper byte 59 173052 010311 mov r3,(r1) ; to command register 60 173054 006061 177776 2$: ror tmcs(r1) ; check tape unit ready bit<0> 61 173060 103375 bcc 2$ ; br if not yet ready 62 63 173062 052711 060017 bis #060017,(r1) ; 800BPI/9ch, REWIND+GO 64 173066 105711 3$: tstb (r1) ; test ready 65 173070 100376 bpl 3$ ; br if not yet 66 67 173072 012761 177777 000002 mov #-1,tmwc(r1) ; set tape byte count 68 173100 112711 000011 movb #011,(r1) ; SPACEFORWARD+GO 69 173104 105711 4$: tstb (r1) ; test ready 70 173106 100376 bpl 4$ ; br if not yet 71 72 173110 005711 tst (r1) ; test error bit<15> 73 173112 100415 bmi 6$ ; br if ERROR; die and try again 74 75 173114 012761 177000 000002 mov #-512.,tmwc(r1) ; set word count 76 173122 011103 mov (r1),r3 ; get current unit in high byte 77 173124 042703 000377 bic #377,r3 ; clear low byte 78 173130 152703 000003 bisb #003,r3 ; READ+GO command 79 173134 010311 mov r3,(r1) ; execute 80 173136 105711 5$: tstb (r1) ; test ready 81 173140 100376 bpl 5$ ; br if not yet 82 83 173142 005711 tst (r1) ; test error bit<15> 84 173144 100004 bpl exit ; br if OK 85 86 173146 000005 6$: reset ; FAILed; reset the world 87 173150 000720 br mtNr ; back up to top and restart 88 89 173152 000137 165564 diag: jmp @#diags ; jump to console diags 90 91 173156 042711 000377 exit: bic #377,(r1) ; NOP+GO command, execute 92 173162 005007 clr pc ; jmp to bootstrap location zero 93 94 ; -------------------------------------------------- 95 96 173164 000000 000000 000000 .word 0,0,0,0,0 ; unused words 173172 000000 000000 97 98 ; -------------------------------------------------- 99 100 173176 .=start+176 101 173176 021526 crc16: .word <021526> ; CRC-16 will go here 102 103 last: ; next boot prom starts here 104 105 .end 105