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[unix-history] / .ref-Research-V6 / usr / source / mdec / dtf.s

/ unix DEC-tape time/mtrack track formatter

nword = 256.
nblock = 578.
endz = 7200.

ps = 177776
tcst = 177340
tccm = 177342
tcwc = 177344
tcba = 177346
tcdt = 177350

       mov     r5,savr5
       mov     sp,savsp

start:
       mov     savr5,r5
       mov     savsp,sp
       jsr     pc,4(r5)
               <set up to format on drive 0\n\0>
               .even

       clr     r0
       mov     $cobtab,r1
1:
       jsr     pc,bcomobv
       mov     r2,(r1)+
       inc     r0
       cmp     r0,$512.
       bne     1b

       mov     $buffer,r0
1:
       mov     $-1,(r0)+
       cmp     r0,$buffer+nword+nword
       blo     1b

       mov     savr5,r5
       jsr     pc,2(r5)

       mov     $340,ps
       mov     $tcdt,r5
       mov     $13,tccm
       jsr     pc,flag

/ 8Kch for end zone

       mov     $endz,r4
1:
       jsr     r0,mtrack; 101101
       dec     r4
       bne     1b

/ foreward guard

       mov     $199.,r4
1:
       jsr     r0,mtrack; 10101
       dec     r4
       bne     1b

/ blocks

       mov     $nblock,r3
1:
       jsr     r0,mtrack; 10101
       jsr     r0,mtrack; 10110
       jsr     r0,mtrack; 11010
       jsr     r0,mtrack; 01000
       jsr     r0,mtrack; 01000
       jsr     r0,mtrack; 01000
       jsr     r0,mtrack; 01000
       mov     $nword-4,r4
2:
       jsr     r0,mtrack; 111000
       dec     r4
       bne     2b
       jsr     r0,mtrack; 111011
       jsr     r0,mtrack; 111011
       jsr     r0,mtrack; 111011
       jsr     r0,mtrack; 111011
       jsr     r0,mtrack; 101001
       jsr     r0,mtrack; 100101
       jsr     r0,mtrack; 10101
       dec     r3
       bne     1b

/ rear guard

       mov     $199.,r4
1:
       jsr     r0,mtrack; 10101
       dec     r4
       bne     1b

/ rear end zone

       mov     $endz,r4
1:
       jsr     r0,mtrack; 10010
       dec     r4
       bne     1b
       clr     tccm

/ end of mtrack pass
/ go back 12 blocks

       mov     $12.,r0
       mov     $4002,tccm
1:
       incb    tccm
       jsr     pc,flag
       dec     r0
       bne     1b

/ put comobv(nblock-1) in everything
/ up to end zone

       mov     $nblock-1,r0
       mov     r0,bn
       jsr     pc,comobv
       mov     $17,tccm
       jsr     pc,flag
1:
       movb    r1,tcst
       mov     r0,(r5)
       jsr     pc,flag1
               br 1b

/ reverse pass put in
/ foreward and reverse
/ block numbers

       mov     $4017,tccm
       jsr     pc,flag
1:
       mov     $nword+3.,r4
2:
       clrb    tcst
       clr     (r5)
       jsr     pc,flag
       dec     r4
       bne     2b

       clrb    tcst
       clr     (r5)
       mov     bn,r0
       jsr     pc,comobv
       jsr     pc,flag
       movb    r1,tcst
       mov     r0,(r5)
       jsr     pc,flag
       dec     bn
       blt     check
       clrb    tcst
       clr     (r5)
       jsr     pc,flag
       clrb    tcst
       clr     (r5)
       jsr     pc,flag
       clrb    tcst
       mov     bn,(r5)
       jsr     pc,flag
       clrb    tcst
       clr     (r5)
       jsr     pc,flag
       clrb    tcst
       clr     (r5)
       jsr     pc,flag
       br      1b

/ foreward pass
/ confirm block numbers
/ write all 1's in data

check:
       clrb    tcst
       clr     (r5)
       jsr     pc,flag1
               br check
       clr     r4
1:
       mov     $3,tccm
       jsr     pc,flag
       cmp     (r5),r4
       bne     error1
       mov     $-nword,tcwc
       mov     $buffer,tcba
       mov     $15,tccm
       jsr     pc,flag
       inc     r4
       cmp     r4,$nblock
       bne     1b
       mov     $3,tccm
       jsr     pc,flag1
               br error2

/ reverse pass
/ confirm block numbers
/ read data and compare
/ to all 1's

1:
       mov     $4003,tccm
       jsr     pc,flag
       dec     r4
       cmp     r4,(r5)
       bne     error3
       mov     $-nword,tcwc
       mov     $buffer,tcba
       mov     $4005,tccm
       jsr     pc,compare
       jsr     pc,flag
       tst     r4
       bne     1b
       mov     $4003,tccm
       jsr     pc,flag1
               br error4
       jsr     pc,compare
       jmp     start

error1:
       mov     $1,r0
       br      1f
error2:
       mov     $1,r0
       br      1f
error3:
       mov     $3,r0
       br      1f
error4:
       mov     $4,r0
       br      1f
error5:
       mov     $5,r0
       br      1f
error6:
       mov     $6,r0
       br      1f
error7:
       mov     $7,r0
1:
       add     $'0,r0
       movb    r0,0f
       mov     tcst,-(sp)
       mov     tccm,-(sp)
       mov     $1,tccm
       mov     savr5,r5
       jsr     pc,4(r5)
               <error>
0:
               <x\ntcst in r0; tccm in r1\n\0>
               .even
       mov     (sp)+,r1
       mov     (sp)+,r0
       0
       rts     pc

compare:
       mov     r0,-(sp)
       mov     $buffer,r0
1:
       cmp     (r0)+,$-1
       bne     error5
       cmp     r0,$buffer+nword+nword
       blo     1b
       mov     (sp)+,r0
       rts     pc

mtrack:
       mov     (r0)+,(r5)
       jsr     pc,flag
       rts     r0

flag:
       bit     $100200,tccm
       beq     flag
       blt     error6
       rts     pc

flag1:
       bit     $100200,tccm
       beq     flag1
       bge     1f
       tst     tcst
       bge     error7
       add     $2,(sp)
1:
       rts     pc

comobv:
       mov     r0,r4
       bic     $!777,r0
       asl     r0
       mov     cobtab(r0),r0
       swab    r0
       clr     r1
       ror     r0
       rol     r1
       asl     r0
       asl     r0
       rol     r1
       swab    r4
       bic     $177401,r4
       bis     cobtab(r4),r0
       rts     pc

bcomobv:
       mov     r0,r2
       bic     $!70,r2
       mov     r0,r3
       mov     $6.,r4
1:
       asr     r3
       dec     r4
       bne     1b
       bic     $!7,r3
       bis     r3,r2
       mov     r0,r3
       mov     $6.,r4
1:
       asl     r3
       dec     r4
       bne     1b
       bic     $!700,r3
       bis     r3,r2
       com     r2
       bic     $!777,r2
       rts     pc

bn:     .=.+2
savr5:  .=.+2
savsp:  .=.+2
cobtab: .=.+1024.
buffer: .=.+nword+nword