Rich Freeman on 12 Mar 2014 15:46:53 -0700

[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: [PLUG] How to Archive Data for 20 Years?

On Wed, Mar 12, 2014 at 6:30 PM, JP Vossen <> wrote:
> I remember doing that.  ramdisk.sys was it, I think?  Then there was the
> Borland "SideKick" TSR that could use that RAM.  And the Quarterdeck QEMM
> and DESKView and good old DR DOS.  Ha, I have my DR DOS 5.0 manual in my
> hand right now (hard to type like that:-).  I *loved* DESKView and DR DOS.

I think most of that stuff used virtual memory on a 386.  EMM386 would
simulate EMS or something like that.

Real EMS was usually on an ISA card and mapped into the address space
of the 8088 by bank-switching, which was why EMS works the way it

The stuff in DOS 5.0+ typically ran on a 386 and just mapped extended
memory into the low memory space via the MMU/etc.  It was
bank-switched in that sense, but in theory an application could have
just accessed it directly as extended memory.  With the ISA card the
switched-out memory wasn't accessible to the address bus at all.

However, I'm not entirely sure that the system in question actually
had EMS after all.  Some research via Google indicates that the AST
Six Pack Plus card only brought the RAM to 640k.  I do think it came
with the RAM drive software all the same (since little software needed

Philadelphia Linux Users Group         --
Announcements -
General Discussion  --