The 'C' language does access hardware directly, and is the most common
language for doing so. (I'm a professional real-time software engineer; been
enjoying this discussion from the sideline ;/)  In 15+ years, I've never
used anything but 'C' or variants (or assembler) to program hardware.

#define   SOME_PERIPHERAL_ADDRESS  0xBADBADBA

//now shove some bits into that peripheral
*(SOME_PERIPHERAL_ADDRESS)= 0x03;

// or read from it...
volatile uint* peripheral_address= SOME_PERIPHERAL_ADDRESS;

uint8_t peripheral_read= *peripheral_address; // assuming an 8-bit data
size, 32 bit address size

This works assuming your operating system allows you to address memory
directly- most OS's usually restrict that to kernel drivers. Don't remember
if DOS does, never used it for anything.

For a project like this I would consider 'ucos', read 'micro-cos'. It's an
open source deterministic real-time OS ported to a wide variety of intel
systems. If your DOS variant isn't intended for real-time work, it is likely
not deterministic, and will also likely have an imprecise scheduler.

--Kenny A.

http://websites.expercraft.com/kennya/


Thanks for the tips Kenny. I'll research RT Linux for direct access to memory.
I am not against using a different OS so I will also take a look.
micro cos.

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As far as I can tell micro cos does not run on PC mother
boards. Probably due to the dynamic ram requiring refresh.
I am not sure if that is done by the processor or the BIOS.
If it is the BIOS one might be able to find a BIOS
that supported static ram. Static ram is available
for PC mother boards.

Paul Lamar