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Using Multiple CPU Cores in DOS? (Miscellaneous)

posted by tom(R) Homepage, Germany, 14.09.2011, 13:24

> To do an INT 15.87 memory transfer on a Sony laptop (approx 5 years old):
> from Real Mode: ~ 15 ms
> w/ HIMEM: ~ 7.5 ms
> w/ HIMEM + EMM386: ~ 300 us
> To do the same thing on a Dell desktop (approx 2 years old):
> from Real Mode: ~ 1 ms
> w/ HIMEM: ~ 1 ms
> w/ HIMEM + EMM386: ~ 40 us
> slowly.

these numbers seem to be somewhat slow but Real Mode INT 15.87 is known to be slow.

you might look at HIMEM how it copies extended memory:

if in protected mode, rely on an efficient implementation

if in real mode,
if FreeDOS
switch to protected mode, copy data, switch back to RM
use unreal mode and copy data

no need to use an extra CPU core to accelerate (OHCI?) USB


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