Home Page Forums MAME MAME Adding memory to an ISA device.

Hi all,

I have developed a (real hardware) device that allows you to add RAM in the upper memory area of an XT class PC, as this can be used by later versions of DOS to store data, load high etc.
I'd like to be able to emulate this in mess, I can see how to map this into the memory map by installing handlers, what I can't see is how to allocate the memory in the first place.

Cheers.

Phill.

There are plenty of examples in MAME:

https://git.redump.net/mame/tree/src/devices/bus/bbc/internal/aries.cpp
https://git.redump.net/mame/tree/src/devices/bus/samcoupe/expansion/onemeg.cpp