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Windows 3.1(1)/9x ET4000/W32 boot problems

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First post, by superfury

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I notice that if I try to boot Windows 95 and 3.1 using the ET4000/W32 drivers, that both operating system (drivers) wait for the accelerator to become ready for use (reading the status register). But since the driver or OS never sets the required bits in CRTC register 36h (it's still set to a value of 43h), the registers it's waiting for are not mapped for the CPU to see, causing it to read a floating bus always(reading FFh on all reads), making it wait infinitely?

Anyone knows anything about this? Does this mean there's a CPU bug that's causing issues?

Author of the UniPCemu emulator.
UniPCemu Git repository
UniPCemu for Android, Windows, PSP, Vita and Switch on itch.io

Reply 1 of 1, by superfury

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Hmmm.... I've just replaced the W32i BIOS with the W32ISA BIOS from 86box... Now Windows 95 while booting sets the value to 0x6B at least once during booting?

I see the 6B write gets reset to 0x43 immediately after various times during booting?

Edit: Interesting! I see a write of 0x6B, 0x43, 0x43. Then when it actually starts the GUI it changes to 0x6B, 0x43, 0x6B! So that's at least working properly now?

VRAM is still always detected as 4MB, though?

Author of the UniPCemu emulator.
UniPCemu Git repository
UniPCemu for Android, Windows, PSP, Vita and Switch on itch.io

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