Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-02, 10:41

by

by superfury

in PC Emulation

in PC Emulation

Having fixed the paging address for 32-bit operand sizes and instruction fetches, it now starts sifting (using the version from yesterday with UniPCemu temporarily patched to set bit 4 of page faults for instruction fetching, in source control with the test patch commented out (the PF_EXTRABITS …

---

Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-02, 06:58

by

by superfury

in PC Emulation

in PC Emulation

Forcing the bit 4 to be set for instruction fetch page faults in UniPCemu causes all of them to give correct results, except the case with a length of 5? Edit: That's opcode E9(short/long JMP rel16/32)? Edit: It observes a length of 2? Edit: OK. That's the ending byte of the instruction's 32-bit …

---

Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-01, 23:29

by

by superfury

in PC Emulation

in PC Emulation

👏Hey that's a great find man! The 32-bit port is quite recent, so I can't say it's wholly surprising... It'd be great if the minimum platform could be lowered even further down to say, i386, but I guess it'll take a while to get there. Could y0u modify the line in your build&disk image to use the I …

---

Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-01, 17:19

by

by superfury

in PC Emulation

in PC Emulation

Perhaps I should look into what's happening in CPL3 (mostly regarding faults etc.)? Edit: OK, I see: 101FFF: OK(with that I mean single step exception). Return EIP=102000(the second page, so that looks correct?). The debugger interrupt it's firing is interrupt 01h? That should be correct? The opcode …

---

Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-01, 14:23

by

by superfury

in PC Emulation

in PC Emulation

It's now logging: 00:24:43:13.04336: DEBUG: attempt.length=1 test.length=1 00:24:43:14.02016: DEBUG: attempt.length=1 test.length=1 00:24:43:14.09056: DEBUG: attempt.length=1 test.length=2 00:24:43:15.06352: DEBUG: attempt.length=1 test.length=2 00:24:43:16.03008: DEBUG: attempt.length=1 test.length …

---

Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-01, 08:55

by

by superfury

in PC Emulation

in PC Emulation

Well, one of those instruction tests seem to somehow have been failing? Are there any other opcodes in that list that can cause issues with Pentium II CPUs (without any non-mandatory (besides FPU/MMX opcodes not being implemented) x86 extensions implemented)? I do notice that it seems to not check …

---

Re: More extended CPU testsuites like test386.asm?

Posted on 2021-07-01, 00:25

by

by superfury

in PC Emulation

in PC Emulation

Oh cool, thanks for pointing that out! You're right, it really is that simple. I've updated the image. Btw, for Bochs you need to enable SMEP, so something like this in .bochsrc: cpuid: smep=true I gave it a go. It didn't get very far: 00:10:24:93.03632: | _|| 00:10:24:93.05232: _ \ _|(_-< _| _| _| …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 23:03

by

by superfury

in PC Emulation

in PC Emulation

After implementing the polarity support into the DAC handling (for EGA only, before the conversion from 6-bit inputs to 32-bit RGB outputs(which are precalculated when the emulator initializes)), the colors now seem to properly work! :D Edit: Interestingly, http://minuszerodegrees.net/video/bios_ …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 22:23

by

by superfury

in PC Emulation

in PC Emulation

Now there's still the issue of some weird colors being displayed (like brown for example) and various display modes somehow getting off-screen pixels they shouldn't (either because of blanking or end of active display)? Also various whites are actually more light greenish? And dark gray seems dark …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 22:20

by

by superfury

in PC Emulation

in PC Emulation

Thanks! I just fired up CheckIt Diagnostics and it reports: Video RAM Size: 256/512K So the video RAM is properly detected now at least!

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 21:46

by

by superfury

in PC Emulation

in PC Emulation

Hmmm.... It uses OUT_DX to write the value to the attribute controller. But afaik, port 3C0 is a port toggled by a 'hidden' flipflop(visible on the VGA though in the upper CRTC register range). I've implemented it so: - Port 3C0 switches between index and data mode (first byte written writes index, …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 21:34

by

by superfury

in PC Emulation

in PC Emulation

Hmmm.... It uses OUT_DX to write the value to the attribute controller. But afaik, port 3C0 is a port toggled by a 'hidden' flipflop(visible on the VGA though in the upper CRTC register range). I've implemented it so: - Port 3C0 switches between index and data mode (first byte written writes index, …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 21:28

by

by superfury

in PC Emulation

in PC Emulation

I've just changed that. Now I'm running through the code at one of the two loops there where the DAC output is 0x32... Oops, in that case you seem to got the DAC index/value mixed up. 0x32 is the index value for the color plane select register (0x12) ORed together with the display enable bit (0x20 …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 21:20

by

by superfury

in PC Emulation

in PC Emulation

I've just changed that. Now I'm running through the code at one of the two loops there where the DAC output is 0x32...

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 21:07

by

by superfury

in PC Emulation

in PC Emulation

Once the color 0x3F is output, the code reads the mux bits 4-5 both set.

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 20:34

by

by superfury

in PC Emulation

in PC Emulation

Well, somehow that test seems to be the one failing? Do you make sure the AC output is zero during blanking? The code writes white characters to the screen and tests for seeing both "bit on" (which should happen during display) and "bit off" (which should happen during blanking). If you keep the …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 20:22

by

by superfury

in PC Emulation

in PC Emulation

Well, somehow that test seems to be the one failing?

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 20:14

by

by superfury

in PC Emulation

in PC Emulation

OK. After some edits, this is what I've got on the video mux inputs it tries to use: //VGA according to the document Second Sight VGA registers const static byte bittablelow[2][4] = {{0,4,1,6},{0,1,4,8}}; //Bit 6 is undefined on EGA! const static byte bittablehigh[2][4] = {{2,5,3,7},{2,3,5,8}}; // …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 19:46

by

by superfury

in PC Emulation

in PC Emulation

OK. So now probably something's going wrong with the red/green/blue/intensify dots? This is how it parses the DAC input (the DAC itself is reduced to the defined 64-color lookup table for EGA only). The DACOutput variable will contain the outputted DAC color from the attribute controller. const …

---

Re: All the exact differences in programming interface for EGA vs VGA?

Posted on 2021-06-30, 19:31

by

by superfury

in PC Emulation

in PC Emulation

OK. C000:03C3 is reached at least once (CX=FFDE).. OK. At C000:03C6, BX eventually ends up wrapping to 0000h? First things first: EGA has the "blanking enable" bit just like CGA and VGA. Bit 0 in the status register set means blanking (horizontal OR vertical), whereas Bit 0 clear means display in …

---