Is it possible that the the buffers are all on 256-byte boundaries because the program is using DPTR to access memory and they only want to deal with updating DPL as opposed to maybe having to update DPH as well? I can't see where this would be an issue in 'C', but I can see it being a lazy approach to buffers in assembly.

It could also be that the original program didn't trust his C compiler to properly manage memory so he/she decided to define memory addresses themselves. Having done work in assembly I've been tempted to do something like that when working in C but, obviously, if you're going to work with C you have to have a certain level of trust in your development tools. Perhaps this programmer didn't have that level of trust (?).

The other possibility is that the program was just poorly written.

I assume there is no information on the original design assumptions and/or the original people responsible?

Craig Steiner