On Jun 20, 2020, at 3:06 PM, Johnny Billquist <b...@update.uu.se> wrote: > > On 2020-06-20 18:52, Dave McGuire wrote: >>> On 6/20/20 5:01 AM, Holm Tiffe wrote: >>> Great. ..and how many VAXen do have 128Mbytes of RAM? >> We have several VAXen at LSSM that have 128MB of RAM or more. One of >> them, a VAX-7000, has 1.5GB. :) > > So do we at Update. But let's face it. It's a very small minority of machines > (VAXen) that can have that much memory. And I don't think anything desk sized > ever could.
I think you could, in theory, on a system with TURBOchannel or an equivalent expansion bus, by making a memory card and then somehow getting the OS to use the extra memory. You might be best off writing a storage driver and using such a card as swap though, as it may be slower than main memory while still being orders of magnitude faster than a disk. That and RAM disks are how NuBus memory cards in Macs were generally used: They were directly mapped, but it wasn’t straightforward to tell the OS to use the memory, and it’s on the other side of a bus with more overhead than main memory anyway. — Chris
