Isn't a bounce buffer just a hack? Wouldn't it be better to just
recognize the ISA  bus limit of 16 megs? There are real 32 bit
bus(es) that don't have a 16 meg limit, EISA PCI and (some)VESA. If
you are going to dump more money into a system, why not be smart
and get hardware that supports what you are trying to do? If you
look around you can find a 1742 Adaptec and a EISA motherboard,
or get a PCI controller and PCI motherboard.

The 1742 that is running in Sasquatch.com was bought for $95
(US) used. A 1542 cost $245 (new). And you wouldn't believe the
performance that is gained with a 32 bit controller.

The Buslogic controllers are also well supported in NetBSD.
We used a 445c for quite a long time till a L2 cache chip on
the motherboard went spoing. At that time we just turned the
L2 cache off till we found the 1742 and EISA motherboard.

Why make life hard on your self with ISA?

Footnote: OS/2 can't use anything over 16 megs with a ISA
bus / controller. It only can use it as a fast swap space,
like a ramdisk.

Jeff Northon

Jeffo@sasquatch.com