scjones@thor.UUCP (Larry Jones) (01/29/91)
In article <5489@husc6.harvard.edu>, albert@endor.uucp (David Albert) writes: > Why is it the case that "SHARE must be loaded for large media" in > MS-DOS 4.01? I ran my computer with a full 40Meg hard disk for a > month without SHARE loaded, with no problems. Might something bad > have happened if I continued? SHARE is needed to allow the old DOS 1.0 FCB functions to work right on a large partition -- if it is not loaded, they wrap around and trash the partition. Since they are significantly faster in some cases than the newer functions that were supposed to replace them, they are still widely used. If you have a large partition and don't load SHARE, you're living on borrowed time. On the other hand, there's a small piece of public domain software that replaces SHARE -- rather than making the FCB functions work right, it intercepts the calls and returns a failure status (and also puts out a message indicating that it happened, I believe). That way you don't trash the disk and it takes up a whole lot less space. I don't remember the name, but it's undoubtedly on SIMTEL. ---- Larry Jones, SDRC, 2000 Eastman Dr., Milford, OH 45150-2789 513-576-2070 Domain: scjones@thor.UUCP Path: uunet!sdrc!thor!scjones Do you think God lets you plea bargain? -- Calvin
etxsral@california.ericsson.se (Lars Nilsson) (01/30/91)
In article <5489@husc6.harvard.edu> albert@endor.UUCP (David Albert) writes: >Why is it the case that "SHARE must be loaded for large media" in >MS-DOS 4.01? I ran my computer with a full 40Meg hard disk for a >month without SHARE loaded, with no problems. Might something bad >have happened if I continued? My version of MS-DOS 4.01 loads SHARE automatically if share can be found on root or in the dos-directory. You should be able to check this with the MEM-program. Give command MEM/PROGRAM or MEM/DEBUG to list resident-programs. /Lars Nilsson -- Lars Nilsson Ericsson Telecom AB , Stockholm - Sweden E-mail: etxsral@california.ericsson.se Fidonet: Lars Nilsson @ 2:201/108.7
toma@sail.LABS.TEK.COM (Tom Almy) (01/30/91)
In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >In article <5489@husc6.harvard.edu>, albert@endor.uucp (David Albert) writes: >> Why is it the case that "SHARE must be loaded for large media" in >> MS-DOS 4.01? >SHARE is needed to allow the old DOS 1.0 FCB functions to work right >on a large partition -- if it is not loaded, they wrap around and trash >the partition. [...] >On the other hand, there's a small piece of >public domain software that replaces SHARE -- rather than making the FCB >functions work right, it intercepts the calls and returns a failure >status (and also puts out a message indicating that it happened, I >believe). That way you don't trash the disk and it takes up a whole lot >less space. I don't remember the name, but it's undoubtedly on SIMTEL. The program is NOSHARE.COM. It is so small I am posting it here for those that are interested. I understand this program is officially "not recommended" by Microsoft. Naturally, use it at your own risk, but it sure beats SHARE, IMHO, as it is not only smaller but also allows programs that SHARE breaks to run. section 1 of uuencode 3.16 of file noshare.com by R.E.M. begin 644 noshare.com MZ0@`]`$`````"@"\FA_'!@4!F!^]_A^)+@<!_.@Z`+@`3,TA`````(#\#W0*` M@/P6=`4N_RZ``+#_SUY86EL>CMNT)<TA'__FM#7-(8G8C,/#N@H`N``QS2'H> M2@`'3D]32$%21>A1`.@\``M">2!4;VT@06QM>>@_`+@A`.C)_Z,D`8D>)@&ZB M)`%2NH``4KH6`%+H40",R%"ZA`!2NB$`4NB7_^FK_UN*!S#D0U-0`<-86E.)= MT^DA`+@-`.@)`+@*`.D#``$``*+&`;1`N0$`NL8!BQ[$`<TAPXG!B=J+'L0!; 3M$#-(<-;65]>XP:,V([`\Z3_XZ3_F `` end sum -r/size 53542/375 section (from "begin" to "end") sum -r/size 4841/244 entire input file -- Tom Almy toma@sail.labs.tek.com <<< Note new address Standard Disclaimers Apply
otto@tukki.jyu.fi (Otto J. Makela) (01/30/91)
In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes:
SHARE is needed to allow the old DOS 1.0 FCB functions to work right
on a large partition -- if it is not loaded, they wrap around and trash
the partition. Since they are significantly faster in some cases than
the newer functions that were supposed to replace them, they are still
widely used. If you have a large partition and don't load SHARE, you're
living on borrowed time.
Does this mean that the COMMAND.COM delete command will trash the hard disk
if SHARE is not loaded ? And they don't say this in the manual ?
--
/* * * Otto J. Makela <otto@jyu.fi> * * * * * * * * * * * * * * * * * * */
/* Phone: +358 41 613 847, BBS: +358 41 211 562 (USR HST/V.32, 24h/d) */
/* Mail: Kauppakatu 1 B 18, SF-40100 Jyvaskyla, Finland, EUROPE */
/* * * Computers Rule 01001111 01001011 * * * * * * * * * * * * * * * * */roger@wrq.com (Roger Fulton) (01/30/91)
In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >SHARE is needed to allow the old DOS 1.0 FCB functions to work right >on a large partition -- if it is not loaded, they wrap around and trash >the partition. Since they are significantly faster in some cases than Does this warning apply to users of Compaq DOS 3.31? (This DOS breaks the 32M barrier.) I've been using this DOS for some time, and have had no disk problems with it. Roger Fulton roger@wrq.com
scjones@thor.UUCP (Larry Jones) (01/31/91)
In article <15404@milton.u.washington.edu>, roger@wrq.com (Roger Fulton) writes: > Does this warning apply to users of Compaq DOS 3.31? (This DOS > breaks the 32M barrier.) I've been using this DOS for some time, > and have had no disk problems with it. I'm not positive, but I don't believe that Compaq 3.31 needs SHARE just for large disks. ---- Larry Jones, SDRC, 2000 Eastman Dr., Milford, OH 45150-2789 513-576-2070 Domain: scjones@thor.UUCP Path: uunet!sdrc!thor!scjones I wonder if you can refuse to inherit the world. -- Calvin
scjones@thor.UUCP (Larry Jones) (01/31/91)
In article <OTTO.91Jan29194929@tukki.jyu.fi>, otto@tukki.jyu.fi (Otto J. Makela) writes: > In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: > SHARE is needed to allow the old DOS 1.0 FCB functions to work right > on a large partition -- if it is not loaded, they wrap around and trash > the partition. Since they are significantly faster in some cases than > the newer functions that were supposed to replace them, they are still > widely used. If you have a large partition and don't load SHARE, you're > living on borrowed time. > > Does this mean that the COMMAND.COM delete command will trash the hard disk > if SHARE is not loaded ? And they don't say this in the manual ? Well, the manual DOES say you need to load SHARE for >32M disks, although it sure would have been nice if it had explained WHY! The problem with FCBs is that, without share, any attempt to read or write past the 32M line wraps around to the beginning of the disk instead. A delete operation only writes the FAT and the directory, not the actual data. The FAT is always near the beginning of the disk, so it should always be below 32M. I would guess that most directories are too, although you certainly should be able to create a subdirectory above 32M. I don't know if that would cause delete to misbehave or not -- perhaps the FCB delete function doesn't use the FCB read and write functions to do it's work?!? On the other hand, what about those people with NOSHARE loaded instead of SHARE (NOSHARE intercepts the FCB function calls and returns a failure status) -- do wildcard deletes stop working, does NOSHARE not trap the FCB delete, or does the FCB call failure cause it to fall back and use the handle functions instead? ---- Larry Jones, SDRC, 2000 Eastman Dr., Milford, OH 45150-2789 513-576-2070 Domain: scjones@thor.UUCP Path: uunet!sdrc!thor!scjones You don't get to be Mom if you can't fix everything just right. -- Calvin
valley@uchicago (Doug Dougherty) (01/31/91)
roger@wrq.com (Roger Fulton) writes: >In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >>SHARE is needed to allow the old DOS 1.0 FCB functions to work right >>on a large partition -- if it is not loaded, they wrap around and trash >>the partition. Since they are significantly faster in some cases than >Does this warning apply to users of Compaq DOS 3.31? (This DOS >breaks the 32M barrier.) I've been using this DOS for some time, >and have had no disk problems with it. No, it applies only to DOS 4.0x+ (which is referred to as "DOS bug.oh" around here...)
toma@sail.LABS.TEK.COM (Tom Almy) (02/01/91)
In article <145@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >[...]On the other >hand, what about those people with NOSHARE loaded instead of SHARE >(NOSHARE intercepts the FCB function calls and returns a failure >status) -- do wildcard deletes stop working, does NOSHARE not trap >the FCB delete, or does the FCB call failure cause it to fall back >and use the handle functions instead? There is no problem with the FCB delete, just with writing to files. NOSHARE traps the FCB open and create calls and returns "failure" which prevents writing to files with the FCB write call. -- Tom Almy toma@sail.labs.tek.com <<< Note new address Standard Disclaimers Apply
marc@rna.UUCP (Marc Johnson) (02/11/91)
In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >In article <5489@husc6.harvard.edu>, albert@endor.uucp (David Albert) writes: >> Why is it the case that "SHARE must be loaded for large media" in >> MS-DOS 4.01? I ran my computer with a full 40Meg hard disk for a >> month without SHARE loaded, with no problems. Might something bad >> have happened if I continued? > >SHARE is needed to allow the old DOS 1.0 FCB functions to work right >on a large partition -- if it is not loaded, they wrap around and trash >the partition. Since they are significantly faster in some cases than >the newer functions that were supposed to replace them, they are still >widely used. If you have a large partition and don't load SHARE, you're >living on borrowed time. On the other hand, there's a small piece of >public domain software that replaces SHARE -- rather than making the FCB >functions work right, it intercepts the calls and returns a failure >status (and also puts out a message indicating that it happened, I >believe). That way you don't trash the disk and it takes up a whole lot >less space. I don't remember the name, but it's undoubtedly on SIMTEL. >---- >Larry Jones, SDRC, 2000 Eastman Dr., Milford, OH 45150-2789 513-576-2070 >Domain: scjones@thor.UUCP Path: uunet!sdrc!thor!scjones >Do you think God lets you plea bargain? -- Calvin YIKES!!! I have had problems with SHARE on my 126Mbyte disk when running Windows 3.0. So, I removed SHARE from my config, and have noticed no other problems. But I am concered about this comment "living on borrowed time"! It doesn't seem to need SHARE to run fine, and with SHARE loaded, Windows has problems. What gives? Also, when my PC arrived from the manufacturer, SHARE was not in the config - obviously they didn't seem to think it was needed. Anyone have a definitive answer on this???? marc =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= = Marc Johnson BITNET: rna!marc@rockvax.bitnet = = Rockefeller Univ. Neurobiology UUCP: ...cmcl2!rna!marc = = New York City INTERNET: marc%rna@rocky2.rockefeller.edu = = (129.85.2.1) = = = = "Gimme the beat boys and free my soul, I wanna get lost in your rock & roll = = ...and drift away" = =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
act@softserver.canberra.edu.au (Andrew Turner) (02/13/91)
In article <1078@rna.UUCP> marc@rna.UUCP (Marc Johnson) writes: >In article <140@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >>In article <5489@husc6.harvard.edu>, albert@endor.uucp (David Albert) writes: >>> Why is it the case that "SHARE must be loaded for large media" in >>> MS-DOS 4.01? I ran my computer with a full 40Meg hard disk for a >>> month without SHARE loaded, with no problems. Might something bad >>> have happened if I continued? >> >>SHARE is needed to allow the old DOS 1.0 FCB functions to work right >>on a large partition -- if it is not loaded, they wrap around and trash >>the partition. Since they are significantly faster in some cases than >>the newer functions that were supposed to replace them, they are still >>widely used. If you have a large partition and don't load SHARE, you're >>living on borrowed time. On the other hand, there's a small piece of >>public domain software that replaces SHARE -- rather than making the FCB >>functions work right, it intercepts the calls and returns a failure >>status (and also puts out a message indicating that it happened, I >>believe). That way you don't trash the disk and it takes up a whole lot >>less space. I don't remember the name, but it's undoubtedly on SIMTEL. >>---- >>Larry Jones, SDRC, 2000 Eastman Dr., Milford, OH 45150-2789 513-576-2070 >>Domain: scjones@thor.UUCP Path: uunet!sdrc!thor!scjones >>Do you think God lets you plea bargain? -- Calvin > >YIKES!!! >I have had problems with SHARE on my 126Mbyte disk when running Windows 3.0. >So, I removed SHARE from my config, and have noticed no other problems. >But I am concered about this comment "living on borrowed time"! It doesn't >seem to need SHARE to run fine, and with SHARE loaded, Windows has problems. >What gives? Also, when my PC arrived from the manufacturer, SHARE was not >in the config - obviously they didn't seem to think it was needed. > >Anyone have a definitive answer on this???? > >marc > >=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= >= Marc Johnson BITNET: rna!marc@rockvax.bitnet = >= Rockefeller Univ. Neurobiology UUCP: ...cmcl2!rna!marc = >= New York City INTERNET: marc%rna@rocky2.rockefeller.edu = >= (129.85.2.1) = >= = >= "Gimme the beat boys and free my soul, I wanna get lost in your rock & roll = >= ...and drift away" = >=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= If you use "modern" programs all the time you may never run into problems using Large-Partitions(over 32M). BUT BEWARE!!!!!!!!!!!!!!!! The deal is that the old FCBs cannot hold pointer information in its "reserved fields", on files that are located past 32 M. When used in a Large-Partition environment, FCB's can be okay as long as the file is physically within the 32M range of the partition. However, if part of the file is past the 32M range, say in the 38th Megabyte area of the partition, the FCB doesn't chuck-up or give an error, it just rolls the pointer value over, the FCBs zero, and it gives Dos a new garbage value as an internal disk pointer - Yippee. The next disk read gives junk to your program, the next disk write junks your disk. It's great fun. The reason Share is the solution is that it was already doing the required fix for a different reason in small partitions. To give file sharing protection in multi-user environments Share would make a copy of the programs FCB in a new local copy within Share and perform the file open from Share's copy of the FCB. In doing so, it technically owned the file, and could effectively perform traffic-cop duty regarding multi-access activity on the file. Since old programs using hardcoded FCB's had to be given a way to run in large-partitions, something had to be done to the FCB disk pointer problem. The solution was to copy the original FCB from within the program to a new "extended" format of the FCB that would be in control by the operating system. The extended form of the FCB with larger fields would be able to support Large-Partitions, and any other extensions in the future. This FCB copy capability was already in FCB's in the current Share facility. Share was just upgraded to not just copy the FCB into it's own area for file access control but to copy it into an extended FCB format, when applicable, for Large-Partition access. As nobody knows the internal code of the programs they run everyday, you can never be positive if a program is using File Handles via extended File FCB's or old FCB's. (Actually if you specify a path, it's 99.44% likely to be extended file FCB's using a file handle.) Since the use of FCB's in Large-FCB's, when accessing the disk past 32M will corrupt the poor user's disk, IBM is alleged to have said(disclaimer here): "this is serious", and even forced the FCB's process to automatically search for Share in the root directory if it had not been explicity loaded in the config file. AAAHHHHHHHH...and that explains why "modern" people who had used only "modern" programs with File Handles(no FCB's) never had any problems. Right. BUT NOT completely safe. Just lucky. The reason Share is an absolute necessity in systems with Large-Partitions is this: An IBM Dos programmer is alleged to have said that even today Dos itself still uses some of the old FCB's for some unspecified internal disk functions! God help us, Microsoft sure didn't. Dos still runs some original Dos 1.1 file access code that requires Share in order to some day wipe out your hard disk. My ego would like to take credit for this stuff but I lifted it out of an article in an Aussie magazine subscription "PC Support Advisor" witten by a Richard Fink, RainTree Computer Systems, PO Box 2339, Mill Valley, CA 94941 USA. So there!!! :-( :-( :-( Grimace, Groan, Moan Grunt. Apologies for the length of this article, but maybe this will be definitive enough. There's sure still to be disbelievers. -- Andrew Turner :-) | E-mail : act@csc.canberra.edu.au Comp. Services Centre | +61 6 2522414 / +61 6 2522401 University of Canberra |________________ fax +61 6 2522400 P.O. Box 1 BELCONNEN ACT 2616 AUSTRALIA |
otto@tukki.jyu.fi (Otto J. Makela) (02/14/91)
In article <1991Feb13.130613.13467@csc.canberra.edu.au> act@softserver.canberra.edu.au (Andrew Turner) writes:
[very informative article...]
An IBM Dos programmer is alleged to have said that even today Dos itself
still uses some of the old FCB's for some unspecified internal disk
functions!
God help us, Microsoft sure didn't. Dos still runs some original Dos 1.1
file access code that requires Share in order to some day wipe out your
hard disk.
[...]
Well, I know that DEL, the COMMAND.COM builtin uses FCB wildcards to get the
job done quickly. Does anyone with a large hard disk care to try this ?
Just remove SHARE.EXE from your \DOS directory and reboot (you should get a
warning message "Share should be loaded"), then delete files in a directory
you know is beyond the 32M barrier (note that you might not have such -- many
disk organizers move all directories adjecent to the root directory -- use a
disk doctor program to check where the directory is located).
If your hard disk gets trashed, you will know that this FCB stuff is true :-)
--
/* * * Otto J. Makela <otto@jyu.fi> * * * * * * * * * * * * * * * * * * */
/* Phone: +358 41 613 847, BBS: +358 41 211 562 (USR HST/V.32, 24h/d) */
/* Mail: Kauppakatu 1 B 18, SF-40100 Jyvaskyla, Finland, EUROPE */
/* * * Computers Rule 01001111 01001011 * * * * * * * * * * * * * * * * */toma@sail.LABS.TEK.COM (Tom Almy) (02/15/91)
In article <1078@rna.UUCP> marc@rna.UUCP (Marc Johnson) writes: >>If you have a large partition and don't load SHARE, you're >>living on borrowed time. On the other hand, there's a small piece of >>public domain software that replaces SHARE -- rather than making the FCB >>functions work right, it intercepts the calls and returns a failure >>status (and also puts out a message indicating that it happened, I >>believe). That way you don't trash the disk and it takes up a whole lot >>less space. I don't remember the name, but it's undoubtedly on SIMTEL. >YIKES!!! >I have had problems with SHARE on my 126Mbyte disk when running Windows 3.0. >So, I removed SHARE from my config, and have noticed no other problems. >But I am concered about this comment "living on borrowed time"! It doesn't >seem to need SHARE to run fine, and with SHARE loaded, Windows has problems. You are only "running on borrowed time" if you have programs that write to files using FCBs. "Modern" programs don't use FCBs, so if your software is all recent you are probably safe. On the other hand, here is the small program that replaces SHARE. Use it for a while and see what breaks (failures are graceful -- you can't open or create any files using FCBs). section 1 of uuencode 3.16 of file noshare.com by R.E.M. begin 644 noshare.com MZ0@`]`$`````"@"\FA_'!@4!F!^]_A^)+@<!_.@Z`+@`3,TA`````(#\#W0*` M@/P6=`4N_RZ``+#_SUY86EL>CMNT)<TA'__FM#7-(8G8C,/#N@H`N``QS2'H> M2@`'3D]32$%21>A1`.@\``M">2!4;VT@06QM>>@_`+@A`.C)_Z,D`8D>)@&ZB M)`%2NH``4KH6`%+H40",R%"ZA`!2NB$`4NB7_^FK_UN*!S#D0U-0`<-86E.)= MT^DA`+@-`.@)`+@*`.D#``$``*+&`;1`N0$`NL8!BQ[$`<TAPXG!B=J+'L0!; 3M$#-(<-;65]>XP:,V([`\Z3_XZ3_F `` end sum -r/size 53542/375 section (from "begin" to "end") sum -r/size 4841/244 entire input file -- Tom Almy toma@sail.labs.tek.com Standard Disclaimers Apply
ts@uwasa.fi (Timo Salmi) (02/17/91)
In article <8975@sail.LABS.TEK.COM> toma@sail.LABS.TEK.COM (Tom Almy) writes: : >section 1 of uuencode 3.16 of file noshare.com by R.E.M. > >begin 644 noshare.com : I understand that you mean well and try to help out the community. We do appreciate that. So don't take this as a flame, it is not meant to be one, but please consider this: 12. ***** Q: May just go ahead and I post binaries in non-moderated groups? A: I would strongly advise against it. On top of that I seem to recall that the net rules don't like it (news.announce.newusers has more information), let's look at this from a purely practical point of view. If netters start posting binaries, several problems will soon occur: 1) The traffic will explode, since it is bound to be more or less haphazard. This is bound to invoke action sooner or later from the systems along the feed and/or net administration. 2) There are no guarantees against trojans and other nasties. (This does not mean that the other methods are absolutely safe, but the likelihood is smaller by far.) 3) The probability of commercial material being posted over the net increases, with all the consequent repercussions. 4) The idea is very wasteful of net resources. Remember that there are over 70000 readers in eg comp.binaries.ibm.pc.d. Much better to put/get stuff into/from the orderly moderated groups, or use anonymous ftp, mail servers, or good BBSes. ................................................................... Prof. Timo Salmi Moderating at garbo.uwasa.fi anonymous ftp archives 128.214.12.37 School of Business Studies, University of Vaasa, SF-65101, Finland Internet: ts@chyde.uwasa.fi Funet: gado::salmi Bitnet: salmi@finfun
iverson@bang.uucp (Tim Iverson) (02/24/91)
In article <OTTO.91Feb14125220@tukki.jyu.fi> otto@tukki.jyu.fi (Otto J. Makela) writes: >In article <1991Feb13.130613.13467@csc.canberra.edu.au> act@softserver.canberra.edu.au (Andrew Turner) writes: >> An IBM Dos programmer is alleged to have said that even today Dos itself >> still uses some of the old FCB's for some unspecified internal disk >> functions! >> God help us, Microsoft sure didn't. Sure they did. Check out comp.com. >Well, I know that DEL, the COMMAND.COM builtin uses FCB wildcards to get the >job done quickly. Does anyone with a large hard disk care to try this ? > > Otto J. Makela <otto@jyu.fi> Works fine. The delete function doesn't exercise the bug, only read and write do. If you'd like to find out if a program uses FCBs, just set the device open/close bit in the DOS "kernel"; as well as causing open/close calls to go to the driver, it also has the side effect of disabling FCBs. When a program uses FCBs, you'll see an 'abort, retry' message (sorry, DOS can't ignore this one!). If you don't like hacking your "OS", you could use a recent copy of the SpeedStor device driver with the /nofcb option. This has roughly the same effect. - Tim Iverson iverson@xstor.com -/- uunet!xstor!iverson