Dave@avignon.gbdt.oz (Dave Moore) (01/23/91)
Just a brief question, On the 68000 minix(s), are you limited to 64k code 64k data? (I guessed you might be, as this is the easiest way to try and stop a task from trashing another task) Can the Amiga minix read Atari minix disks? Dave. ============================================================================ Dave Moore | EMail: Dave@avignon.gbdt.oz |My other computer is a PDP-8E. Disclaimer: Of course these are my opinions, whose else should I post?
mboen@peun33.sni.de (Martin Boening) (01/23/91)
In <04036@avignon.gbdt.oz> Dave@avignon.gbdt.oz (Dave Moore) writes: >Just a brief question, > On the 68000 minix(s), are you limited to 64k code 64k data? > (I guessed you might be, as this is the easiest way to try and > stop a task from trashing another task) Well, it's been my experience that you aren't! (GCC is an example) Programs can have a large code segment and allocate lots of memory. However, many system calls use 'int' arguments (read, malloc, etc. come to mind), so the maximum for a single call to malloc has in my experience been 32 KB. (With unsigned it it might have been 64KB, but we don't use unsigned int). The same with read - you can't read more than 64KB in one read. (Or was that 32KB as well I'll have to check). So if you need large memory segments you'll have to go through a loop. Maybe someday somebody will come up with a 32-bit kernel for minix st. > Can the Amiga minix read Atari minix disks? That I don't know. The Atari MINIX file systems reside on standard format disks, so far as sectoring etc. is concerned. The fs code is supposed to be identical between MINIX PC and ST, so why not AMIGAMINIX as well. Therefore I'd think if you AMiga can read disks formatted by TOS (i.e. read the physical sectors from the tracks) there should be no problems. But I haven't tried it, so don't bet on it. > Dave. So long. Maybe some minix guru can verify/contradict what I've said? Martin -- Email: in the USA -> mboening.pad@nixdorf.com outside USA -> mboening.pad@sni.de Paper Mail: Martin Boening, Nixdorf Computer AG, SNI STO SI 355, Pontanusstr. 55, 4790 Paderborn, W.-Germany (Phone: +49 5251 146155)
laverman@cs.rug.nl (Bert Laverman) (01/23/91)
> Just a brief question, I'll try to give brief answers. > On the 68000 minix(s), are you limited to 64k code 64k data? No :-) > (I guessed you might be, as this is the easiest way to try and > stop a task from trashing another task) Actually, they invented something else for that: chmem(1). You have to announce in advance your maximal usage, and that's what you'll get! Meaning that if you _don't_ use it all, there'll be a lot of dead space floating around. This is why people with an expensive processort try to introduce demand paging... > Can the Amiga minix read Atari minix disks? I am told this is the case. Never tried it though; I've got an ST, but no Amiga ;-) With harty greetings, Bert Disclaimer: Don't blame my Boss, He doesn't know what I'm saying either. _____________________________________________________________________ / \ | "The only problem with parameterization is that | | you never have enough parameters" - J.B. Goodenough | | at the RMISE Reuse Workshop | \_____________________________________________________________________/ Bert Laverman Dept. of Computing Science laverman@cs.rug.nl Groningen University bert@arrakis.nl.mugnet.org P.O.Box 800, 9700 AV Groningen The Netherlands (+31 50)/(050) 633948
eesrajm@cc.brunel.ac.uk (Andrew J Michael) (01/24/91)
In article <mboen.664614594@peun33>, mboen@peun33.sni.de (Martin Boening) writes: > In <04036@avignon.gbdt.oz> Dave@avignon.gbdt.oz (Dave Moore) writes: > > > > Can the Amiga minix read Atari minix disks? > > That I don't know. The Atari MINIX file systems reside on standard format > disks, so far as sectoring etc. is concerned. The fs code is supposed to be > identical between MINIX PC and ST, so why not AMIGAMINIX as well. Therefore > I'd think if you AMiga can read disks formatted by TOS (i.e. read the > physical sectors from the tracks) there should be no problems. But I haven't > tried it, so don't bet on it. > > > Dave. > > So long. Maybe some minix guru can verify/contradict what I've said? > > Martin OK. The ST and PC disk formats are NOT compatible due to endian problems in the way the disk structure is defined. The Atari and Amiga disks are entirely compatible unless the Atari owner has done something evil and used a non-standard disk format (which is why I deplore the "improvement" in the ST to allow it to access disks other than the original MINIX-ST format). The MacMINIX disks are wierd - they use a Mac format disk which thinks it is a MINIX file system, so you can't read them on anything except a Mac. I hope that makes it plain :-) Regards Andy Michael -- Andy Michael (eesrajm@cc.brunel.ac.uk) "You might think that. I 85 Hawthorne Crescent couldn't possibly comment." West Drayton Middlesex UB7 9PA
halderen@fwi.uva.nl (Berry A.W. van Halderen (I88)) (01/25/91)
mboen@peun33.sni.de (Martin Boening) writes: >> Can the Amiga minix read Atari minix disks? >That I don't know. The Atari MINIX file systems reside on standard format >disks, so far as sectoring etc. is concerned. The fs code is supposed to be >identical between MINIX PC and ST, so why not AMIGAMINIX as well. Therefore >I'd think if you AMiga can read disks formatted by TOS (i.e. read the >physical sectors from the tracks) there should be no problems. But I haven't >tried it, so don't bet on it. >> Dave. >So long. Maybe some minix guru can verify/contradict what I've said? AmigaMinix does use the same kind of diskformat as STminix, so you can read, write, and execute (!? I though so) ST disks. This is why AmigaMinix is kinda slow when accessing disks (the amiga diskdrive doesn't like to read and write IBM-formatted disks). Cu, Berry Email: halderen@fwi.uva.nl /*****************************************************************************/ /* Money doesn't come / / Berry van Halderen */ /* in large quantities / / Student at the University of */ /* \ \/ / Amsterdam, the Netherlands */ /* \/\/ Email: halderen@fwi.uva.nl */ /* ..!hp4nl.nluug.nl!fwi.uva.nl!halderen */ /*****************************************************************************/
tsarna@polar.bowdoin.edu (Tyler Sarna) (01/28/91)
In comp.os.minix, "Berry A.W. van Halderen (I88" <halderen%FWI.UVA.NL@VM1.NoDak.EDU> writes: > AmigaMinix does use the same kind of diskformat as STminix, so you can > read, write, and execute (!? I though so) ST disks. Yes, this is true. > This is why AmigaMinix is kinda slow when accessing disks (the amiga > diskdrive doesn't like to read and write IBM-formatted disks). Not true! I beleive this to be a problem with the floppy driver in minix - recent posts point to this. Amiga floppy drives are physically the same as PC/ST drives - unlike Mac drives. The difference between the native formats of the PC/ST and the Amiga is due to software/controller issues. AmigaDOS reads/writes whole tracks, which are broken into sectors only logically. This is why the AmigaDOS driver is called "trackdisk.device". They also use two different encoding methods - I beleive the PC/ST uses GCR and the Amiga MFM. There are two main side-effects of the Amiga native format: 1) More data can be stored on a disk: 880K for AmigaDOS versus 720K for PC/ST and 800K for the MAC. 2) Most PC (I don't know about the ST) floppy controllers simply can't deal with the whole-track layout, which is why the PC/(ST ?) can't be made to read AmigaDOS disks. On the other hand, the Amiga can be easily made to read and write other disks, since the drive hardware is the same. There are several approaches to this: 1) A program that reads/writes PC (or minix) disks, such as Dos-2-Dos (or minix transfer). 2) A new driver/filesystem, such as MSH or a commercial program whose name escapes me a the moment. With MSH, for example, you simply install a new new device-driver (messydisk.device) and a new filesystem handler (MessyFileSystem) [note: pokes at MS-DOS ("Messy-DOS") brain damage are the MSH author's, not my own :-)]. The user sets up the correct mounlist entry, and then does "mount msh:". From then on, device msh: acts just like any other amiga drive, except that it has "8.3" filename constraints. As a sidenote, due to the lovely modular design of AmigaDOS, one can use StandardFileSystem with messydisk.device to get an Amiga filesystem on PC layout disks (which could presumably be read by someone with a PC who wanted towrite a program to traverse the Amiga filesystem). One can also use MessyFileSystem with trackdisk.device to make MS-DOS disks which can't be read on an MS-DOS machine, or with scsi.device for someone who wants a MS-DOS filesystem hard drive. These are all pretty useless ideas, but it's nice not to be limited. What DOES sound like it might be useful is to use a PD handler (I forget the name) which makes a raw stream device out of trackdisk.device, allowing someone to, say, use tar and write to the floppy as if it were a file. This handler allows and .device to be used, so my idea is to use it with messydisk.device from MSH and be able to exchange tar disks between AmigaDOS and Minix. I haven't tried this yet, but if it works it would be far superior than transfer. Another possibility is to write a MinixFileSystem to use with messydisk.device, and have transparent access to minix disks. It could even support file links under AmigaDOS 2.0! ------///------------------------------------------------------------ /// Tyler "Ty" Sarna E-Mail: tsarna@polar.bowdoin.edu \\\/// "The Electric Monk was a labour-saving device..." --\XX/---------------------------------------------------------------