Rich Freeman on 12 Mar 2014 15:46:53 -0700 |
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Re: [PLUG] How to Archive Data for 20 Years? |
On Wed, Mar 12, 2014 at 6:30 PM, JP Vossen <jp@jpsdomain.org> 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 does. 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 640k). Rich ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug