fixed some address math and the decrement in the divide

diff --git a/FIG68K.S b/FIG68K.S
index 50e3a7f..42dd9ac 100644 (file)
--- a/FIG68K.S
+++ b/FIG68K.S
@@ -85,7 +85,20 @@
 * it should be primarily used for study, practice, and research.\r
 *********\r
 \r
+* Some processor-specific stuff:\r
 NATWID EQU     4       ; bytes per natural integer/pointer\r
+* The assembler ought to have defined these, but I don't see them in the manual:\r
+* User program condition codes:\r
+F_CARY EQU     $0001\r
+F_OVER EQU     $0002\r
+F_ZERO EQU     $0004\r
+F_NEG  EQU     $0008\r
+F_EXT  EQU     $0010\r
+* System status flags (68000/68010/CPU32):\r
+F_SYS  EQU     $2000\r
+F_TRAC EQU     $8000\r
+* Ignoring the interrupt flags for now\r
+*\r
 *  The original version was developed on an AMI EVK 300 PROTO\r
 *  system using an ACIA for the I/O.\r
 *  This version is developed targeting the Atar ST.\r
@@ -867,6 +880,7 @@ PFNDBR      MOVE.B  (XPD)+,D1       ; Is high bit of character in dictionary entry set?
        CMP.B   (YPA0)+,D1      ; Compare "last" characters.\r
        BEQ.S   FOUND           ; Matches even if dictionary actual length is shorter.\r
 PFNDLN MOVE.L  (XPD),XPD       ; Get previous link in vocabulary. (auto-inc in 6809 probable error, no inc in 6800)\r
+       MOVE.L  XPD,D0          ; On 68K, flags not in effect for MOVEA, TST not available.\r
        BNE.S   PFNDLP          ; Continue if link not=0\r
 *\r
 *      not found :\r
@@ -1172,28 +1186,28 @@ USTAR   DC.L    *+NATWID
 * Using the bit divide to reduce testing burden, working in registers.\r
 USLASH:\r
        DC.L    *+NATWID\r
-       MOVEM.L (PSP),D0/D1/D2  ; D1:D2 by D0   (40~)\r
-       MOVE.W  #33,D3  ; bit ct                (8~)\r
+       MOVEM.L (PSP),D0/D1/D2  ; D1:D2 by D0   (40~ ignore attempts to count cycles)\r
+       MOVE.W  #32,D3  ; bit ct for DBcc       (8~)\r
 USLDIV:\r
        CMP.L   D0,D1   ; divisor               (6~)\r
-       BHS.S   USLSUB                          (10/12~)\r
-       AND     #~8,CCR ; X-carry clear         (20~)\r
+       BHS.S   USLSUB                          (8/10~)\r
+       AND     #~F_EXT,CCR     ; X-carry clear         (20~)\r
        BRA.S   USLBIT                          (10~)\r
 USLSUB:\r
        SUB.L   D0,D1                           (6~)\r
-       OR      #8,CCR  ; quotient, (X-carry set)       (20~)\r
+       OR      #F_EXT,CCR      ; quotient, (X-carry set)       (20~)\r
 USLBIT:\r
        ROXL.L  #1,D2   ; save it               (8~)\r
-       SUBQ.W  #1,D3   ; more bits?            (4~)\r
-       BEQ.S   USLR                            (10/12~)\r
-       ROXL.L  #1,D1   ; remainder             (8~)\r
-       BCC.S   USLDIV                          (10/12~)\r
-       BRA.S   USLSUB                          (10~)   (~90*32=~2880+entry+exit, about 800 μS at 4 MHz)\r
+       DBF     D3,USLMOR       ; more bits? Don't mess with CCR        ((12/14)/10~)\r
 USLR:\r
        LEA     NATWID(PSP),PSP                 (8~)\r
        MOVE.L  D1,NATWID(PSP)                  (16~)\r
        MOVE.L  D2,(PSP)                        (12~)\r
        BRA.W   NEXT\r
+USLMOR\r
+       ROXL.L  #1,D1   ; remainder             (8~)\r
+       BCC.S   USLDIV                          (8/10~)\r
+       BRA.S   USLSUB                          (10~)   (~90*32=~2880+entry+exit, about 800 μS at 4 MHz)\r
 \r
 * The following is not yet functional, only here to help me remember:\r
 * cUSLASH      DC.L    *+NATWID\r
@@ -1231,11 +1245,11 @@ USLR:
 * B0USLDIV:\r
 *      CMP.L   (PSP),D2        ; divisor\r
 *      BHS.S   B0USLSUB\r
-*      AND     #~8,CCR ; X-carry clear\r
+*      AND     #~F_EXT,CCR     ; X-carry clear\r
 *      BRA.S   B0USLBIT\r
 * B0USLSUB:\r
 *      SUB.L   (PSP),D2\r
-*      OR      #8,CCR  ; quotient, (X-carry set)\r
+*      OR      #F_EXT,CCR      ; quotient, (X-carry set)\r
 * B0USLBIT:\r
 *      ROXL.W  2*NATWID+NATWID/2(PSP)  ; save it\r
 *      ROXL.W  2*NATWID(PSP)           ; in memory has only 16-bit by 1 bit form\r
@@ -3395,11 +3409,11 @@ EXPEC3  DC.L    DUP,LIT16
        DC.W    $D      ; ( carriage return )\r
        DC.L    EQUAL,ZBRAN\r
        DC.L    EXPEC4-*-NATWID\r
- DC.L BREAK    ; dbg\r
+* DC.L BREAK   ; dbg\r
        DC.L    LEAVE,DROP,BL,ZERO,BRAN ; I think this is the NUL terminator.\r
        DC.L    EXPEC5-*-NATWID\r
 EXPEC4 DC.L    DUP\r
- DC.L BREAK    ; dbg\r
+* DC.L BREAK   ; dbg\r
 EXPEC5 DC.L    I,CSTORE,ZERO,I,ONEP,CSTORE,ZERO,I,TWOP,CSTORE  ; save two NULs to make sure address is even\r
 EXPEC6 DC.L    EMIT,XLOOP\r
        DC.L    EXPEC2-*-NATWID\r
@@ -3558,6 +3572,7 @@ WORD3     DC.L    IN,AT,PLUS,SWAP,ENCLOS,HERE,LIT16
        DC.B    ')'|$80\r
        DC.L    WORD-5-NATWID\r
 PNUMB  DC.L    DOCOL\r
+*      DC.L    BREAK   ; DBG *****\r
 PNUMB2 DC.L    ONEP,DUP,TOR,CAT,BASE,AT,DIGIT,ZBRAN\r
        DC.L    PNUMB4-*-NATWID\r
        DC.L    SWAP,BASE,AT,USTAR,DROP,ROT,BASE\r
@@ -3567,6 +3582,7 @@ PNUMB2    DC.L    ONEP,DUP,TOR,CAT,BASE,AT,DIGIT,ZBRAN
 PNUMB3 DC.L    FROMR,BRAN\r
        DC.L    PNUMB2-*-NATWID\r
 PNUMB4 DC.L    FROMR\r
+*      DC.L    BREAK   ; DBG *****\r
        DC.L    SEMIS\r
 *\r
 * ======>>  140  <<\r
@@ -3704,7 +3720,7 @@ IDFLAT    DC.L    *+NATWID
        DC.B    '.'|$80\r
        DC.L    IDFLAT-7-NATWID\r
 IDDOT  DC.L    DOCOL,PAD\r
-*      DC.L    BREAK\r
+*      DC.L    BREAK   ; DBG *****\r
        DC.L    LIT16\r
        DC.W    MAXNML  ; Why did I hard code this?\r
 *      DC.L    WIDTH,ONEP      ; Because WIDTH is a (USER) variable.\r
@@ -3839,7 +3855,8 @@ INTER5    DC.L    HERE,NUMB,DPL,AT,ONEP,ZBRAN
        DC.L    DLITER,BRAN\r
        DC.L    INTER7-*-NATWID\r
 INTER6 DC.L    DROP,LITER\r
-INTER7 DC.L    QSTACK,BRAN\r
+*INTER7        DC.L    QSTACK,BRAN\r
+INTER7 DC.L    BREAK,QSTACK,BRAN       ; DBG\r
        DC.L    INTER2-*-NATWID\r
 *      DC.L    SEMIS   never executed\r
 \r
@@ -3930,7 +3947,7 @@ QUIT      DC.L    DOCOL,ZERO,BLK,STORE
 *  which gets a line of input, does it, prints " OK"\r
 *  then repeats :\r
 QUIT2  DC.L    RPSTOR,CR,QUERY\r
-       DC.L    BREAK\r
+*      DC.L    BREAK   ; DBG *****\r
        DC.L    INTERP,STATE,AT,ZEQU\r
        DC.L    ZBRAN\r
        DC.L    QUIT3-*-NATWID\r