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DMA: Change the MegaPC 0528h to 0580h.

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OBattler
2024-02-02 19:56:55 +01:00
parent 9e7fc6a60d
commit ff5ea614ee
1 changed files with 4 additions and 3 deletions
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7
src/dma.c
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@@ -959,15 +959,16 @@ dma_page_read(uint16_t addr, UNUSED(void *priv))
and at least 0x0898 for 25 MHz, everything below 0x06e0 and at least 0x0898 for 25 MHz, everything below 0x06e0
is assumed to be 16 MHz. Given that for some reason, this is assumed to be 16 MHz. Given that for some reason, this
does not occur on 86Box, we have to work around it here, does not occur on 86Box, we have to work around it here,
we return 0x0528 for 16 MHz, because it's the next in the we return 0x0580 for 16 MHz, because it logically follows
mathematical sequence (it equals 0x06e0 - (0x0898 - 0x06e0)). */ in the sequence (0x06e0 = 0x0898 * (20 / 25), and
0x0580 = 0x06e0 * (16 / 20)). */
case 0x0081: case 0x0081:
if (cpu_busspeed >= 25000000) if (cpu_busspeed >= 25000000)
ret = 0x98; ret = 0x98;
else if (cpu_busspeed >= 20000000) else if (cpu_busspeed >= 20000000)
ret = 0xe0; ret = 0xe0;
else else
ret = 0x28; ret = 0x80;
break; break;
case 0x0082: case 0x0082:
if (cpu_busspeed >= 25000000) if (cpu_busspeed >= 25000000)