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swtp6800: Correct overflow(V) flag status bit

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This commit is contained in:
Bill Beech 2020-02-04 16:27:19 -07:00
parent 08330de7f4
commit 4cd8aff027
1 changed files with 10 additions and 6 deletions
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16
swtp6800/common/m6800.c
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@ -538,8 +538,9 @@ t_stat sim_instr (void)
PC = CPU_BD_get_mword(0xFFFB) & ADDRMASK;
break;
case 0x40: /* NEG A */
op1 = A;
A = (0 - A) & 0xFF;
COND_SET_FLAG_V(A & 0x80);
condevalVa(A, op1);
COND_SET_FLAG(A,CF);
COND_SET_FLAG_N(A);
COND_SET_FLAG_Z(A);
@ -621,8 +622,9 @@ t_stat sim_instr (void)
SET_FLAG(ZF);
break;
case 0x50: /* NEG B */
op1 = B;
B = (0 - B) & 0xFF;
COND_SET_FLAG_V(B & 0x80);
condevalVa(B, op1);
COND_SET_FLAG(B,CF);
COND_SET_FLAG_N(B);
COND_SET_FLAG_Z(B);
@ -706,9 +708,10 @@ t_stat sim_instr (void)
break;
case 0x60: /* NEG ind */
DAR = get_indir_addr();
lo = (0 - CPU_BD_get_mbyte(DAR)) & 0xFF;
op1 = CPU_BD_get_mbyte(DAR);
lo = (0 - op1) & 0xFF;
CPU_BD_put_mbyte(DAR, lo);
COND_SET_FLAG_V(lo & 0x80);
condevalVs(lo, op1);
COND_SET_FLAG(lo,CF);
COND_SET_FLAG_N(lo);
COND_SET_FLAG_Z(lo);
@ -816,9 +819,10 @@ t_stat sim_instr (void)
break;
case 0x70: /* NEG ext */
DAR = get_ext_addr();
lo = (0 - CPU_BD_get_mbyte(DAR)) & 0xFF;
op1 = CPU_BD_get_mbyte(DAR);
lo = (0 - op1) & 0xFF;
CPU_BD_put_mbyte(DAR, lo);
COND_SET_FLAG_V(lo & 0x80);
condevalVs(lo, op1);
CLR_FLAG(CF);
if (lo)
SET_FLAG(CF);