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MMR0 (bits 10 & 11 always 0) fix

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folkert van heusden 2022-03-22 10:20:20 +01:00
parent eeed41c62e
commit ff8539565f
1 changed files with 3 additions and 7 deletions
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10
bus.cpp
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@ -206,12 +206,8 @@ uint16_t bus::read(const uint16_t a, const bool word_mode, const bool use_prev)
} }
else { else {
if (a == 0177572) { if (a == 0177572) {
uint16_t t = (run_mode << 5) | // kernel == 00 D(fprintf(stderr, "read MMR0\n");)
((c -> getRegister(7) >> 13) << 1) | // page nr return MMR0;
0 // MMU enabled
;
D(fprintf(stderr, "read MMU MMR0 %o\n", t);)
return t;
} }
if (a == 0177574) { // MMR1 if (a == 0177574) { // MMR1
@ -433,7 +429,7 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
if (a == 0177572) { // MMR0 if (a == 0177572) { // MMR0
D(fprintf(stderr, "write set MMR0: %o\n", value);) D(fprintf(stderr, "write set MMR0: %o\n", value);)
MMR0 = value; MMR0 = value & ~(3 << 10); // bit 10 & 11 always read as 0
return MMR0; return MMR0;
} }