bparsia@eagle.wesleyan.edu (05/04/90)
In article <8904@hydra.gatech.EDU>, gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) writes: > Here is some clarification of my earlier posting regarding differing > virtual memory capabilities for the IIcx and the IIci. According > to the June MacUser, regarding how much virtual memory your Mac can > use, "The rule is 14 megabytes minus 1 megabyte for each NuBus card. > For the SE/30, that means 14 megabytes; forthe Mac II, which has at > minimum a video card, no more than 13 megabytes can be used. The > exceptions are the IIci and IIfx, on which VM will simulate nearly a > gigabyte of memory, if you've got the disk space." These statements > refer to the virtual memory capability which will be made available > by System 7.0, whenever it may be released. I believe that this is incorrect. The "14-1 per slot" rule is for Connectix' Virtual, not for system 7.0. 7.0 should let you access as much memory as you have disk space with *any* 68030 (or 68020 + a PMMU). As sys 7.0 is currently non-existing, the only way to get virtual memory is with Virtual. The IIci *can* potentially have more VM than the IIcx, if one uses the on board video circutry rather than a NuBus video card. If VM is all one wants at the moment, I don't think that the extra megabyte is worth the cost differential. However, I'm confused. I thought that the Mac OS currently supports *only* 8 megs of memory. Does Virtual patch this in some manner? In any case, with system 7.0, all restrictions on memory will be for all intents and purposes lifted (with the advent of 32-bit memory addresses). I don't know what > hardware differences exist that allow the IIci and IIfx to do better > than the other macs. As far as virtual memory is concerned, there are none. The PMMU is all you need, and with the '030, it's what you get. Does anyone know if the limitations for > Connectix' Virtual are the same? See above. > > -- > WILLETT,THOMAS > Georgia Institute of Technology, Atlanta Georgia, 30332 > uucp: ...!{allegra,amd,hplabs,ut-ngp}!gatech!prism!gt4586c > Internet: gt4586c@prism.gatech.edu Let me know if I have erred. I wish someone official like from Apple would post a full, clarificatory article on this topic, as I have seen *alot* of misinformation flying about (of which my current posting may be one). Bijan J. Parsia
gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) (05/04/90)
Here is some clarification of my earlier posting regarding differing
virtual memory capabilities for the IIcx and the IIci. According
to the June MacUser, regarding how much virtual memory your Mac can
use, "The rule is 14 megabytes minus 1 megabyte for each NuBus card.
For the SE/30, that means 14 megabytes; forthe Mac II, which has at
minimum a video card, no more than 13 megabytes can be used. The
exceptions are the IIci and IIfx, on which VM will simulate nearly a
gigabyte of memory, if you've got the disk space." These statements
refer to the virtual memory capability which will be made available
by System 7.0, whenever it may be released. I don't know what
hardware differences exist that allow the IIci and IIfx to do better
than the other macs. Does anyone know if the limitations for
Connectix' Virtual are the same?
--
WILLETT,THOMAS
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp: ...!{allegra,amd,hplabs,ut-ngp}!gatech!prism!gt4586c
Internet: gt4586c@prism.gatech.edurob@uokmax.uucp (Bolo) (05/04/90)
In article <8904@hydra.gatech.EDU> gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) writes: > >virtual memory capabilities for the IIcx and the IIci. According >to the June MacUser, regarding how much virtual memory your Mac can >use, "The rule is 14 megabytes minus 1 megabyte for each NuBus card. >For the SE/30, that means 14 megabytes; forthe Mac II, which has at >minimum a video card, no more than 13 megabytes can be used. The >exceptions are the IIci and IIfx, on which VM will simulate nearly a >gigabyte of memory, if you've got the disk space." ... >Does anyone know if the limitations for >Connectix' Virtual are the same? Virtual allows 15 mb - 1 mb per occupied slot. I'm running it on a Mac II with the obligatory video card and "About the Finder" shows 14,336k. I would guess that the comment about the ci and fx implies that the ROM Memory Manager has been made "32-bit clean" in those machines. It is apparently NOT clean in the earlier machines. Anyone know if a ROM swap is in the works, for those of us who can't afford the (quite reasonable) IIfx upgrade? Robert >WILLETT,THOMAS -- Robert K. Shull rob@uokmax.ecn.uoknor.edu chinet!uokmax!rob
cs223101@umbc5.umbc.edu (CMSC 223/01011) (05/04/90)
In regards to your comments, according to my Mac //ci manual the //ci can address 128 megs of ram, using 16 meg simms at one per slot. I believe someone said this earlier, but it may have been ignored. I can give page and paragraph references if required. Also, I find that I cannot use Virtual. Even having it in my system folder causes the system to hang upon booting. Anyone else experience this with a //ci? Do I just have an old version of Virtual ( can't remember off the top of my head which one I DO have)? [RICH]
hammersslammers1@oxy.edu (David J. Harr) (05/04/90)
Regarding the MacUser claim that the limit is 14Mbytes - 1Mbyte per slot: Running Virtual on a Mac II here, I see that my available memory is 15Mbytes under the Finder. The rule is 16 Mbytes minus one per slot (2^24 = 16Mbytes) NOT 14 Mbytes. As for the claim about the IIci and the IIfx, the only thing I can think of that is different between them and the others in the Mac '030 families is that the ROMs are supposedly 32 bit clean and so will allow the system to use 32 bit addressing. However, by the time the system catches up and is rewritten to handle 32 bit addressing (= 4 Gigabytes), the folks at Apple will have kindly put together the slew of patches necessary to allow the rest of us to run under 32 bit mode. There is nothing in the II, IIx, SE/30, or IIcx that inherently prevents them from addressing 32 bits of memory space; anyone who has run A/UX has used the CPU in the 32 bit mode. So, the only thing that is stopping us is the "unclean" system, which will be taken care of in 7.0. David
ts@cup.portal.com (Tim W Smith) (05/05/90)
Shouldn't the SE/30 lose a meg when a card is installed, since the SE/30 expansion slot acts like a NuBus slot to the software? Tim Smith
bill@cambridge.apple.com (Bill St. Clair) (05/06/90)
From: bparsia@eagle.wesleyan.edu Newsgroups: comp.sys.mac Date: 3 May 90 17:50:11 GMT Distribution: usa In article <8904@hydra.gatech.EDU>, gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) writes: [stuff deleted...] I believe that this is incorrect. The "14-1 per slot" rule is for Connectix' Virtual, not for system 7.0. 7.0 should let you access as much memory as you have disk space with *any* 68030 (or 68020 + a PMMU). As sys 7.0 is currently non-existing, the only way to get virtual memory is with Virtual. Not entirely true. System 7.0's virtual memory will have the same limitation ("14-1 per slot") as Virtual unless you have 32-bit clean ROMs (standard on the IIci & IIfx). The 32-bit clean ROMs will work in the IIcx, but you'll have to buy and install them (they come on a SIMM, but I know nothing about their where to buy them). The IIci *can* potentially have more VM than the IIcx, if one uses the on board video circutry rather than a NuBus video card. If VM is all one wants at the moment, I don't think that the extra megabyte is worth the cost differential. True. However, I'm confused. I thought that the Mac OS currently supports *only* 8 megs of memory. Does Virtual patch this in some manner? The limitation is that the ROM is expected to be at address 800000 hex (8 Megs). Virtual fools the finder into thinking that there is an application sitting in memory where the ROM is (or something like that). Thus your virtual address space is split up into an 8 Meg chunk and a "6 meg - 1 meg per filled NuBus slot" chunk. In any case, with system 7.0, all restrictions on memory will be for all intents and purposes lifted (with the advent of 32-bit memory addresses). And the Mac will be able to thrash almost like a real operating system. I don't know what > hardware differences exist that allow the IIci and IIfx to do better > than the other macs. No hardware differences, just the 32-bit clean ROMs. As far as virtual memory is concerned, there are none. The PMMU is all you need, and with the '030, it's what you get. Does anyone know if the limitations for > Connectix' Virtual are the same? Let me know if I have erred. I wish someone official like from Apple would post a full, clarificatory article on this topic, as I have seen *alot* of misinformation flying about (of which my current posting may be one). I work for Apple, but I'm no official, so I include the standard disclaimer that all my musings are my own opinions, not my employer's. Bill St. Clair bill@cambridge.apple.com