ken@dali.gatech.edu (Ken Seefried iii) (09/21/90)
--- Is Acorn and/or VLSI Technologies working on an updated MMU for the ARM? Surely noone 'round there thinks 32MB processes and a 4MB physical memory is remotely adequate.... -- ken seefried iii ken@dali.gatech.edu "Vee haf veyz off making you talk...release da veasles..."
rcpieter@svin02.info.win.tue.nl (Tiggr) (09/21/90)
ken@dali.gatech.edu (Ken Seefried iii) writes: >Is Acorn and/or VLSI Technologies working on an updated MMU for the >ARM? Surely noone 'round there thinks 32MB processes and a 4MB >physical memory is remotely adequate.... Ahem. The numbers should read 32Mb logical address space (i.e. the kernel must fit in there somewhere as well), and 16Mb physical memory space (by using 4 memory controllers (the maximum)). The 32Mb _is_ imposed by MEMC1. But remember that the ARM only has 26 address lines, giving 64Mb addressable memory. Hacking it to have it have more address lines is non trivial, since the software model of the CPU would change, because the 32 bit PC register also contains the status and mode flags... But this doesn't answer your question... Tiggr
d6b@psuecl.bitnet (09/24/90)
In article <1436@svin02.info.win.tue.nl>, rcpieter@svin02.info.win.tue.nl (Tiggr) writes: > Ahem. The numbers should read 32Mb logical address space (i.e. the kernel > must fit in there somewhere as well), and 16Mb physical memory space (by using > 4 memory controllers (the maximum)). Does Acorn actually sell a computer that is upgradable to 16MB, or is this just theory? Acorn's machines are OK, but they remind me of Atari STs... (I'm an Amiga fan). -- Dan Babcock
kers@hplb.hpl.hp.com (Chris Dollin) (09/24/90)
d6b@psuecl.bitnet writes: | [Quote omitted] | Does Acorn actually sell a computer that is upgradable to 16MB, or is this | just theory? Acorn's machines are OK, but they remind me of Atari STs... | (I'm an Amiga fan). Yes, Acorn sell 16Mb machines, the recently-announced Unix R*40 machines (I can't recall the digit that the * replaces); they're also fitted with ARM 3's, so they run pretty (30MHz clock?) fast too. I'm looking forward to upgrading my home machine sometime to Arm 3 + 8Mb (no, of *course* I'm not running Unix on it). Why do the Acorn machines remind you of STs? Regards, Kers. -- Regards, Kers. | "You're better off not dreaming of the things to come; Caravan: | Dreams are always ending far too soon."
gcwilliams@watdragon.waterloo.edu (Graeme Williams) (09/25/90)
In article <13942@hydra.gatech.EDU> ken@dali.gatech.edu (Ken Seefried iii) writes: > >Is Acorn and/or VLSI Technologies working on an updated MMU for the >ARM? Surely noone 'round there thinks 32MB processes and a 4MB >physical memory is remotely adequate.... I hope so - I have one of Acorn's animals (one of the very first Archimedes, an A310 circa 1987) and have been contemplating upgrading it as soon as 1. The ARM3 (24Mhz ??) chip becomes available as the CPU (not as an add on co-processor). The ARM2 in my machine is only idling at 8Mhz - though it'll still blow the doors off of all but the hottest 386's. 2. The MMU is altered so one could extend physical memory to more than 4 Mb - I seem to recall that Acorn initially designed the MMU to address 64Mb of physical memory, but lopped 4 address lines off once in production. Is this so?? If it is, it wouldn't be difficult to pop them back on. As an aside, I'm in Canada and news about Acorn products is *NON-EXISTANT* - further *NOBODY* I know here has ever heard of an Archimedes let alone knows what it is, or what it can do! So if there's anyone out there who could tell me about recent Acorn products ??? New machines?? Upgrades?? 32-bit colour?? Thanks. Graeme Williams gcwilliams@watdragon.waterloo.edu
andras@alzabo.uucp (Andras Kovacs) (09/25/90)
Some news about Acorn, Archimedes and MMU:
Acorn does have an ARM3 with 8 KB on-chip cache. It is available in 20 MHz
and 30 MHz versions (2 micron and 1.5 micron is the difference). The faster
one is roughly about 650 pounds (I mean on a card with the new - faster -
MMU so you just plug it in); VERY steepy price indeed for North Americans
who are accustomed to IBM PC clone prices. But in your old Archimedes 310
(with 8 MHz bus clock) it supposedly around 10-12 MIPS.
So Acorn has that mentioned UNIX machine. They just announced a new non-UNIX
one, the Archimedes A540. It has
- ARM3 (30 MHz) with 12 MHz RAM speed
- 4 MB RAM expandable to 16 MB by plug-in modules
(they use their new MEMC - MMU - for it so they can drive it 12 MHz
but one MEMC can handle only 4 MB. So they master-slave together max.
five of them - one master and four slaves - which increases the max.
RAM to 16 MB. But there they hit a hard limit; without redesigning the
MEMC they cannot go beyond 16 MB)
- 100 MB SCSI 18 ms drive
- RISC-OS (not bad for an OS)
- 13.5 MIPS
- apparently it runs with standard VGA and SVGA monitors
And now:
!!! With (software) PC Emulator it runs as fast as an AT !!!
Whoa!
Price: 2995 pound sterling
I have an A310 which I am very happy with; the only problem is to upgrade.
I paid 200 pounds for a ST-506 hard drive controller (without drive :-) );
some third party developers in England want around 575 pounds for a 4 MB
upgrade card. I am doing 4 MB upgrade DIY but it is very tedious; I have
to "remap" 7 pins on a 256x4 Kbit chip to match the pinout of a 64x4 Kbit
one. And there is 32 of the suckers on the motherboard. Of course all 32
chips are soldered into a 4-layer board; I succeeded to de-solder them and
put in sockets but now I have to do the RAMs.
Anyway, if anyone wants more info send me a mail.
Egeszsegetekre
Andras Kovacs
...@alzabo.andrasd6b@psuecl.bitnet (09/26/90)
In article <KERS.90Sep24132344@cdollin.hpl.hp.com>, kers@hplb.hpl.hp.com (Chris Dollin) writes: > Why do the Acorn machines remind you of STs? Both depend on a single, central, memory controller that can only handle 2 banks. So if you buy with 1MB, it's a hack to upgrade it to 4MB, and once at 4MB, it's non-expandible. Also, I don't believe DMA from plug-in cards is possible (at least not that I can see). HOWEVER, as several people have pointed out via email and posting, the latest Acorn machines are much more sophisticated. I have the same problem the poster from Canada has: no information! -- Dan Babcock > Regards, Kers.