Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!decwrl!labrea!agate!helios.ee.lbl.gov!pasteur!ames!mailrus!cornell!uw-beaver!ssc-vax!uvicctr!tholm From: tholm@uvicctr.UUCP (Terrence W. Holm) Newsgroups: comp.os.minix Subject: re: MINIX expanded memory Message-ID: <508@uvicctr.UUCP> Date: 22 Sep 88 20:13:36 GMT Reply-To: tholm@uvicctr.UUCP (Terrence W. Holm) Organization: University of Victoria, Victoria B.C. Canada Lines: 62 > Subject: Minix EMS Ramdisk > > One item of extension to Minix which seems to me terribly obvious > but I have not seen anything about is a ramdisk implementation > based on expanded memory. > > Thos Sumner (thos@cca.ucsf.edu) BITNET: thos@ucsfcca >> From: rwberry@hubcap.UUCP (Robert W Berry) >> >> A while back people got a EMS ramdisk going on AT-class machines, but only >> with the help of the AT ROM BIOS, which had an interrupt service perfectly >> suited to copying blocks of text in and out of EMS. No such luck on the >> PC cards. First of all, Dr. Tanenbaum made an EXTENDED memory interface for the ramdisk. This was based on an AT BIOS call. This would not work on our AT clones, so we wrote away to Intel for information on their board. We received lots of goodies, but no information on how it is REALLY implemented. So, Ed picked up an Intel card, told me what was there - and then we spent an evening disassembling LIM 4.0 to determine how the board was accessed. We wrote a replacement routine for em_xfer in klib88.s, this code does some out's to an "Intel Above Board" EXPANDED memory. And then a rep/mov. (There are no BIOS calls here.) We wanted to test the code on an XT, assuming that there must be at least one type of XT EXPANDED memory card that would work. Our request in comp.os.minix started as shown below. We never received any responses..... > From: tholm@uvicctr.UUCP (Terrence W. Holm) > Subject: need test site for expanded memory > Date: 18 May 88 21:38:39 GMT > Organization: University of Victoria, Victoria B.C. Canada > Lines: 217 > > We are looking for Minix users who would like to test > our "expanded" memory handler on their PC/XT. > > We converted to "expanded" memory because our two AT clone > keyboards would not work with "extended" memory. (Yes, > its true.) > > The following code has been tested on AT's with real > Intel Above Board "expanded" memory. We want someone > with a PC/XT to try this code. > > . . . code removed . . . > ---------------------------------------------------------- Edwin L. Froese uw-beaver!ubc-cs!mprg!handel!froese Terrence W. Holm uw-beaver!uvicctr!tholm