daniel@hexagon.pkmab.se (Daniel Deimert) (05/25/90)
In article <718@zinn.MV.COM> kgg@zinn.MV.COM (Kenn Goutal) writes: >You might also want to consider Mark Williams C and its companion >development system, the micro-shell. It sounds, from a previous >article, as if OS/9 is considerably more powerful. I've never >used OS/9 so I can't compare either performance, features, or price. >But I do use the MWC micro-shell and like it well enough. I don't think the MWC "msh" really is what he's looking for (Stefan is a friend of mine). It has no multi-tasking capabilities (minix has, I presume?), and it is not compatible with unix on a source code level. Maybe the Gnu gcc with David B's "RTX" would do the trick. Someone who knows where we can get hold of gcc and rtx? Are rtx released to the public domain or is it still sold?? We do not have access to ftp. -- Daniel Deimert, Fridstavagen 4, S-715 94 Odensbacken, SWEDEN Internet: daniel@pkmab.se or daniel@hexagon.pkmab.se
SA44@LIVERPOOL.AC.UK (Kevin Maguire) (05/30/90)
In article <669@hexagon.pkmab.se>, daniel@hexagon.pkmab.se (Daniel Deimert) says: > >In article <718@zinn.MV.COM> kgg@zinn.MV.COM (Kenn Goutal) writes: >>You might also want to consider Mark Williams C and its companion > I don't think the MWC "msh" really is what he's looking for (Stefan is >a friend of mine). It has no multi-tasking capabilities (minix has, I >presume?), and it is not compatible with unix on a source code level. >Maybe the Gnu gcc with David B's "RTX" would do the trick. Better sticking with minix and gcc. Yes minix is multi-tasking and gcc tex, flex, yacc you name it everything is available for ST minix. (Not PC though as the PC version has a limit of 64K for text and data space 128K for big (?) processes). The ST is only limited by memory size. OF course it's nice to have 4M as minix has no virtual memory, but my 2.5M system is fine and my older 1M system is okay for one user. You can have multiple logins via the rs232 and midi ports ;-) Kevin Maguire Nsfnet : sa44%liv.ac.uk@nsfnet-relay.ac.uk Uucp : ...!mcsun!ukc!liv-ib!sa44
baffoni@alcor.usc.edu (Juxtaposer) (06/07/90)
In article <90150.161022SA44@LIVERPOOL.AC.UK> SA44@LIVERPOOL.AC.UK (Kevin Maguire) writes: >space 128K for big (?) processes). The ST is only limited by memory size. >OF course it's nice to have 4M as minix has no virtual memory, but Disclaimer: I do not claim to know much about the ST architecture but... I was wondering if there are ANY (preferably transparent) programs out that will enable an ST to use its hard-drive as a source of virtual-memory: As long as the software you are using doesn't need to skip all over memory while it is running, this sure would be a nice way to give yourself an 8-meg machine (4meg chipped + swap 6meg or so [leaving 2meg for system,etc]) or some other exotic memory size by utilizing the memory storage most people already have. Or even give someone with a 1meg-machine 4meg of useable memory. Of course by using certain replacement policies you can speed up what could be excruciatingly slow, but for some programs like word processors, I can't see that it would slow it down that much if most of what is in memory (pages of information) were read into the ST in bursts. Would this be so impossible? Or have I been hitting the caffeine just a little too much ...:) > >Kevin Maguire > >Nsfnet : sa44%liv.ac.uk@nsfnet-relay.ac.uk >Uucp : ...!mcsun!ukc!liv-ib!sa44 -Mike Baffoni baffoni@alcor.usc.edu or baffoni@skat.usc.edu
hyc@math.lsa.umich.edu (Howard Chu) (06/07/90)
In article <10060@chaph.usc.edu> baffoni@alcor.usc.edu (Juxtaposer) writes: >In article <90150.161022SA44@LIVERPOOL.AC.UK> SA44@LIVERPOOL.AC.UK (Kevin Maguire) writes: >>space 128K for big (?) processes). The ST is only limited by memory size. >>OF course it's nice to have 4M as minix has no virtual memory, but > >Disclaimer: I do not claim to know much about the ST architecture but... > > > I was wondering if there are ANY (preferably transparent) programs out that >will enable an ST to use its hard-drive as a source of virtual-memory: As long >as the software you are using doesn't need to skip all over memory while it is >running, this sure would be a nice way to give yourself an 8-meg machine (4meg >chipped + swap 6meg or so [leaving 2meg for system,etc]) or some other exotic >memory size by utilizing the memory storage most people already have. Or even >give someone with a 1meg-machine 4meg of useable memory. Of course by using >certain replacement policies you can speed up what could be excruciatingly >slow, but for some programs like word processors, I can't see that it would >slow it down that much if most of what is in memory (pages of information) were >read into the ST in bursts. This seems to be impossible on a plain ST. A paged virtual memory system automatically implies page-faults - traps generated by accessing a virtual page that isn't currently in real memory. First there's no straightforward way to distinguish a virtual address from a physical address. This is pretty much essential, that is, you must be able to keep the two distinct. Second, assuming you have some way of recognizing an access to a virtual address, and generating a page fault if the corresponding page isn't in physical memory, you can't reliably restart the instruction that caused the fault to occur. (This is *really* a problem if you fault while accessing a memory mapped I/O device, but we'll leave that alone for now...) Before the advent of the 68010 with VM support on the chip, there were one or two 68000 based Unix systems on the market. I think Sun & Apollo used custom designed MMUs, which probably suspended the CPU in lieu of interrupting it. This implies that the VM management was handled almost entirely in hardware, with no input from the OS. Another approach was to use two 68000s running in parallel. On a page fault, one 68000 is suspended, the other traps & does the necessary VM magic, the suspended processor is resumed, and the 2nd processor re-syncs at the following instruction. So... Unless you can add in some whiz-bang hardware, I don't think you can get away with it. And even if you can, I don't think it'll run very quickly, but that's probably not important. The main thing is, you can get better performance using a chip that was designed to handle VM in the first place. (68010 on up. 68020 would probably be minimum, though I *think* you can use the PMMU with the 68010.) -- -- Howard Chu @ University of Michigan ... the glass is always greener on the side ...
rlcollins@miavx1.acs.muohio.edu (Ryan 'Gozar' Collins) (06/08/90)
In article <1990Jun6.225653.24296@math.lsa.umich.edu>, hyc@math.lsa.umich.edu (Howard Chu) writes: > In article <10060@chaph.usc.edu> baffoni@alcor.usc.edu (Juxtaposer) writes: >>In article <90150.161022SA44@LIVERPOOL.AC.UK> SA44@LIVERPOOL.AC.UK (Kevin Maguire) writes: >>>space 128K for big (?) processes). The ST is only limited by memory size. >>>OF course it's nice to have 4M as minix has no virtual memory, but >> >>Disclaimer: I do not claim to know much about the ST architecture but... >> >> >> I was wondering if there are ANY (preferably transparent) programs out that >>will enable an ST to use its hard-drive as a source of virtual-memory: As long >>as the software you are using doesn't need to skip all over memory while it is >>running, this sure would be a nice way to give yourself an 8-meg machine (4meg > > This seems to be impossible on a plain ST. A paged virtual memory system > automatically implies page-faults - traps generated by accessing a virtual > page that isn't currently in real memory. First there's no straightforward [ Stuff deleted] > So... Unless you can add in some whiz-bang hardware, I don't think you can > get away with it. And even if you can, I don't think it'll run very quickly, > but that's probably not important. The main thing is, you can get better > performance using a chip that was designed to handle VM in the first place. > (68010 on up. 68020 would probably be minimum, though I *think* you can use the > PMMU with the 68010.) > -- > -- Howard Chu @ University of Michigan > ... the glass is always greener on the side ... I thought OS-9 offered virtual memory? Or did I hear wrong.... Goz -- ~~~~~~~~~~~~~~~~~~~~~~~~~ Ryan 'Gozar' Collins ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "When you have Super Powers, rlcollins@miavx1.BITNET hard work is easy" rc1dsanu@miamiu.BITNET -Dufus from Ducktails ~~~~~~~~~~~~~~~~~~~~~~Yea, right, thats what I said.~~~~~~~~~~~~~~~~~~~~~~~~~