So I need to adjust the int10_modes VGA settings of the source code to make it work on a real IBM VGA (which I'm emulating as far as I can find the documentation on it)? Or are the int10_modes settings correct and I need to fix my VGA script (which seems to have bugs)?

I'm currently testing my VGA emulation routines using different graphics modes. Atm modes 0xF gives no output and mode 4, 5 and 6 give a quarter of the horizontal scanlines with (as far as I can see in the tiny window which contains the pixels) 8 or 9 pixels (depending on the 8/9 pixel character …

What's the difference between the VGA's Dot Clock rate (divide by 1, 2 or 4) and character clock (divide by 1, 2 or 4)? How does the DIVIDE SCANLINE CLOCK BY 2 affect ouput? How do any of them affect output?

My current code for read and write operations is: (OPTINLINE is a define which gives __inline or inline depending on the compiler) //decodeCPUaddress(Write from CPU=1; Read from CPU=0, offset (from VRAM start address), planes to read/write (4-bit mask), offset to read/write within the plane(s)). …

I've looked at the FreeVGA docs again: Sequencer Memory Mode Register bit 5 seems to have the highest priority, forwarding to all planes if set (using the read map during read or the bit mask during write to select the correct plane(s), sequentually accessing it). When it's set to 0, even addresses …

When I look at the miscellanious output register, which is set at int10_modes.cpp, it sets bit 5 on always. Shouldn't this bit be cleared always? (When a real VGA gets the bit set, it will redirect all VRAM output to the high planes (plane 2&3 instead of 0&1), which will cause text modes to redirect …

I'm running my emulator with a copy of the int 10h service of dosbox, although some types converted to my emulator's types. I've based my VGA emulation on the FreeVGA specs and IBM documentation. I'm trying to get all video modes working (00-13h), but atm only mode 2/3 and the 16/256/mode 0xF color …

what isn't? the code should be visible? or the goto?

My compiler seems to have problems with some c++ code (it wont recognise anything if i try it. Using pspsdk, with uses gcc iirc). Gotos seem to be a little bit faster than an infinite for(;;) loop. I dont know if it works since I dont have anything to test it with (testsuite etc), nor have I written …

Update: /* DMA Controller (8237A) */ #include "headers/types.h" //Basic types! #include "headers/hardware/ports.h" //Port support! #include "headers/mmu/mmu.h" //Memory support! typedef void (*DMAWriteBHandler)(byte data); //Write handler to DMA hardware! typedef byte (*DMAReadBHandler)(); //Read …

What are the minimum chips that need to be emulated on a x86 emulator? Anyone knows if this is enough to run MS-DOS/Windows/Linux/*nix? Currently implemented in my emulator: ------------------------------------------------ CPU/FPU: - 80(1)86 CPU. Still working on 286+. - FPU opcodes throw exceptions …

I've written some DMA controller emulation for my emulator I'm making. Anyone knows if this is correct? Atm I'm not sure about the final lines (pointed in the code with 'not entirely sure about this'). delay(us) delays the thread a specified time, allowing other threads (core CPU/EMU thread and …