Updated: Jun 12
Back in January of this year, I posted a list of potential roadmap items for my 26 build. See 80286 System Roadmap (rehsdonline.com). As I reflect on the list I posted at the time, I feel like I have made good progress.
ISA video card supporting 640x480, 16 bits per pixel color.
BIOS support of critical interrupts to run FreeDOS.
ISA sound card.
ISA IDE interface card with CF Card.
FreeDOS loaded from CF Card and running.
DMA support (hardware at least). BIOS support and testing still needed.
Onboard flash BIOS programming.
System timer using VIA. complete
Continue to implement BIOS interrupts (e.g., IDE disk writing).
Update the ISA IDE interface card PCB. The current version has many bodge wires to address design changes post-PCB-design.
Bug fixing and performance improvements to better support FreeDOS.
Run a couple of basic DOS games (snake, Tetris, etc.).
Try out a custom C/C++ DOS application or two.
Sound card working in FreeDOS.
Ethernet network access with basic TCP/IP support. I will likely offload much of this to an Arduino (Mega or Due?) and communicate from the 286 to the Arduino with SPI.
RAM card, using address space above the 1 MB address. Maybe I can support 4 MB of extended RAM.
Updated ISA VGA card. Add support for accessing VRAM from both the current 0xA0000 64K window and full memory mapping from an address space above 1 MB? Hardware scrolling? Onboard video co-processor?
Possibly, start a 386 DX build, leveraging the current system board design as a starting point.
I'd love to hear other ideas. Drop me a note.
More to come...