Hi

IIRC, memory refresh on i386 boxen is done via a programmable timer and a DMA
controller. There is no memory controller in the i386 architecture to manage
refresh, so the DMA/timer chips were used to do it in software.

Also, it's very likely that a h/w device that busmaters can starve the
onboard DMA h/w for time to do the refresh.

I remember running a program on my first 8Mhz/i386 in DOS to slow the refresh
rate and thus get a few more clock cycles for appliocation code - the speed
increase was visible!

--et