FLXIBM USERS GUIDE FOR RSX-11M V03.2 BL26 VAX / VMS V3.0 MARCH 1982 ERIK A. ROSDOL DISTRICT SOFTWARE SUPPORT AUEA/VIENNA PROJECT NR. VNB 707013 LIBRARY RETRIEVAL NR. UT004-79VN UT008-82VN Page 2 INDEX CHAPTER 1 PREFACE CHAPTER 2 PURPOSE OF F L X I B M CHAPTER 3 FUNCTIONAL SPECIFICATION 3.1 Hardware required . . . . . . . . . . . . . . 3-1 3.1.1 RSX-11/M . . . . . . . . . . . . . . . . . . 3-1 3.1.2 VAX/VMS . . . . . . . . . . . . . . . . . . 3-1 3.2 IBM Compatibility . . . . . . . . . . . . . . 3-2 3.2.1 Recording scheme . . . . . . . . . . . . . . 3-2 3.2.2 Logical format . . . . . . . . . . . . . . . 3-3 3.2.2.1 Header description . . . . . . . . . . . . . 3-3 3.2.2.2 Data field description . . . . . . . . . . . 3-3 CHAPTER 4 GENERATING F L X I B M 4.1 RSX-11/M Systems . . . . . . . . . . . . . . . 4-1 4.2 VAX / VMS Systems . . . . . . . . . . . . . . 4-3 CHAPTER 5 INVOKING FLXIBM 5.1 RSX-11/M Systems . . . . . . . . . . . . . . . 5-1 5.2 Installing FLXIBM in your system . . . . . . . 5-1 5.3 Invoking the permanently installed FLXIBM . . 5-1 5.3.1 Invoking FLXIBM and returning control to MCR 5-2 5.3.2 Invoking and passing control to FLXIBM . . . 5-2 5.3.3 Invoking FLXIBM to run under another UIC . . 5-2 5.4 Invoking uninstalled FLXIBM . . . . . . . . . 5-3 5.5 VAX / VMS Systems . . . . . . . . . . . . . . 5-4 CHAPTER 6 USING INDIRECT FILES CHAPTER 7 FILE SPECIFICATION 7.1 Entering command strings . . . . . . . . . . . 7-1 7.2 Entering file specifiers . . . . . . . . . . . 7-1 7.3 FLXIBM Switches . . . . . . . . . . . . . . . 7-3 7.3.1 Use of the "RS" switch . . . . . . . . . . . 7-3 7.3.2 Use of the "LI" switch . . . . . . . . . . . 7-3 7.3.3 Use of the "FU" switch . . . . . . . . . . . 7-3 7.3.4 Use of the "DE" switch . . . . . . . . . . . 7-4 7.3.5 Use of the "IN" switch . . . . . . . . . . . 7-4 7.3.6 Use of the "HE" switch . . . . . . . . . . . 7-4 Page 3 CHAPTER 8 3741 SPECIALS 8.1 Record length . . . . . . . . . . . . . . . . 8-1 8.2 File protection . . . . . . . . . . . . . . . 8-1 8.2.1 Bypass . . . . . . . . . . . . . . . . . . . 8-1 8.2.2 Write protect . . . . . . . . . . . . . . . 8-2 8.3 Multivolume datasets . . . . . . . . . . . . . 8-2 8.4 Space allocation . . . . . . . . . . . . . . . 8-2 CHAPTER 9 ERROR MESSAGES CHAPTER 1 PREFACE The RSX-11M/VMS FLXIBM Users Guide is a reference manual for general users of the operating system. This manual contains a description of the RSX-11M/VMS FLXIBM utility program, command formats and syntax rules for using services provided by the utility, and general usage information. General users are persons familiar with the services provided by the computer systems and who use such services regularly. General users use RSX-11M/VMS utility services to perform tasks of varying degrees of complexity; from relatively straightforward tasks, such as creating and maintaining clerical files, to more complex tasks, such as generating and maintaining the operating system at an installation. Other useful general-purpose commands are described in the operating system specific Operator's Procedures Manual. These documents describe services provided by the Monitor Console Routine (MCR) for RSX-11M or VMS. These documents also provide information on procedures and conventions associated with the operation of the RSX-11M operating system or the application migration executive (AME) under which FLXIBM is run on VMS. PREFACE Page 1-2 The information in this document is subject to change without notice and should not be construed as a commitment by Digital Equipment Corporation. Digital Equipment Corporation assumes no responsibility for any errors that may appear in this document. This software has a designated support category of customer installed/ customer supported [old category C], which means, that it is provided on an "as is" basis. Any software services, if available, will be provided at the then current charges. Digital shall have the right to make additional charges for any additional effort required to provide services resulting from customer use of other than the current unaltered release of the software operated, in accordance with this product specification. Digital reserves the right, without prior approval from or notice to the purchaser, to make changes to the products (a) which do not effect physical or functional interchangeability or performance at a higher level of assembly or (b) when required for purposes of safety or (c) to meet product specifications. CHAPTER 2 PURPOSE OF F L X I B M The purpose of the FBM utility is to provide the operator of an RSX-11M/VMS installation with RX01/RX02 with the capability of transferring data to or from an IBM 3741 formatted floppy disk. FBM provides the operator with an RSX-11M compatible utility capable of reading or writing EBCDIC characters to and from an IBM 3741 formatted floppy, utilizing the standard IBM 3741 file structure and the procedure for IBM basic data exchange. This means: o The dataset is organized sequentially. o Max. record length is 128. bytes. o Records are fixed length, unblocked, unspanned. o Dataset identifier (pos. 6-22) max. 8 positions. o No support for alternate physical record relocation. o Single density mode only on RX02. FBM also provides the operator with the capability of reading and writing files to or from a standard file structured device, using Digital Equipment's standard file structure, FILES-11, under RSX-11M and VMS. CHAPTER 3 FUNCTIONAL SPECIFICATION The FBM utility will provide the user with an RSX-11M compatible utility capable of reading/writing EBCDIC formatted characters from/to an IBM 3741 standard floppy disk. The utility will operate as an independent, unprivileged task under RSX-11M or an compatibility mode task under VMS and will read/write ASCII formatted characters from/to a Digital Equipment standard, FILES-11 structured disk, using RSX-11M standard file organization. Files created on VMS conform to version 2 of the on disk file structure ODS. Translation is transparent to the user because it is done by the AME. These files can then be processed by any VAX/VMS utilty. 3.1 Hardware required 3.1.1 RSX-11/M In order to run the FBM utility a standard RSX-11M configuration is required, with one or more additional RX01/RX02 floppy drives. Refer to the Software Product Description for RSX-11M V03.2 SPD 14.35 to obtain a detailed description of possible minimum hardware configurations. The minumum core requirements for the FBM utility is approximately 6K, which means that it can be run in the standard utility partition GEN. 3.1.2 VAX/VMS In order to run the FBM utility a standard VAX/VMS configuration is required, with one or more additional RX02 floppy drives. Refer to the Software Product Description for VAX/VMS V3.0 SPD 25.1.12 to obtain a detailed description of possible minimum hardware configurations. FUNCTIONAL SPECIFICATION Page 3-2 3.2 IBM Compatibility IBM compatibility can mean media, plug, or file compatibility. In the case of the RX01/RX02 we mean media compatibility - that is a diskette written on the RX01/RX02 may be read by an IBM machine or IBM compatible machine and vice versa. For software compatibility to occur, additional software efforts to achieve common file structure will have to be done. IBM media compatibility defines the physical, electrical, and logical aspects of data interchange with the 3740 and associated devices. In the following paragraph we will attempt to describe the significant characteristics of the 3740 scheme. 3.2.1 Recording scheme The recording scheme used is "double frequency". In this method, data is recorded between bits of a constant clock stream. The clock stream consists of a constant pattern of one flux reversal per 4 micro seconds. A data "one" is indicated by an additional reversal between clocks, doubling the bit stream frequency, hence the name. A data "zero" is indicated by no flux reversal between clocks. A constant stream of ones would appear as a "2F" bit stream, and a constant stream of zeros as of "1F" or fundamental frequency bit stream. 3.2.2 Logical format Data is recorded only on one side of the diskette. This surface is divided into 77 concentric circles or "tracks" numbered 0 through 76. Each track is divided into 26 sectors numbered 1-26. Each sector contains two major fields: the header field and the data field. 3.2.2.1 Header description - The header field is broken into 7 bytes of information and is preceded by a field of 33 "zero" bytes for synchronization. The bytes of the header field are allocated as follows: BYTE 1 - ID Address mark BYTE 2 - Track address BYTE 3 - Zeros (one byte) BYTE 4 - Sector address FUNCTIONAL SPECIFICATION Page 3-3 BYTE 5 - Zeros (one byte) BYTE 6 - CRC-16 first byte BYTE 7 - CRC-16 second byte 3.2.2.2 Data field description - The data field is broken into 131 bytes of information and is preceded by a field of zero's to identify the beginning of the data field. BYTE 1 - Deleted data address mark BYTE 2-129 - Data storage BYTE 130,131 - CRC-16 Checksum FUNCTIONAL SPECIFICATION Page 3-4 And that completes IBM media compatibility. Any physical identical media recorded as described in the preceding formats can be read by the 3740 family devices. If IBM file structures are adhered to, then the operating systems can also communicate. CHAPTER 4 GENERATING F L X I B M 4.1 RSX-11/M Systems The FBM utility is distributed on a standard floppy disk only. It contains an object library, an overlay description file and the task-build command files for mapped and unmapped systems. The following is a list of all files on the distribution medium: UIC=[1,2] FLXIBM.HLP ;FLXIBM Help file UIC=[1,20] FBM.OLB ;FLXIBM Object library FBMBLD.CMD ;Build command file un- mapped UIC=[1,24] FBMBLD.CMD ;Build command file mapped UIC=[77,10] FLXIBM.RNO ;Manual in RUNOFF format FLXIBM.MEM ;Manual in Print format UIC=[200,200] FBMGEN.CMD ;FLXIBM Generation CMD file DYDRV.MAC ;Patched RX02 driver DYDRVASM.CMD ;DY assembly command file DYDRVBLD.CMD ;DY task build command file The complete generation process is controlled by an indirect command file "FBMGEN.CMD", which guides the user through all necessary steps of the generation process. GENERATING F L X I B M Page 4-2 First mount the distribution floppy and copy [200,200]FBMGEN.CMD to the system disk: >SET /UIC=[200,200] >PIP SY:/NV=DX:[200,200]FBMGEN.CMD Now invoke the indirect command file "[200,200]FBMGEN.CMD" and answer all questions according to your configuration. >SET /UIC=[200,200] >@FBMGEN >; >; COPY DISTRIBUTION KIT >; >* WHAT IS YOUR DIST. DEVICE [DXn:, DYn: [S]]: DX0: >ALL DX0: >MOU DX0:FBM >SET /UIC=[1,1] >PIP SY:[*,*]*.*/NV/FO/UF=DX:[*,*]*.* >DMO DX: >DEA DX0: >; >; GENERATE FBM >; >SET /UIC=[1,24] >TKB @FBMBLD >INS [1,54]FBM >; >; FBM GENERATION COMPLETE ! >; At this point FBM is generated and ready to use. Refer to chapter 5 for detailed operating instructions. Observe, that the generation command file installs this utility in the core resident system only. If you want to install FBM permanently, you must use the Virtual Console Routine VMR, in order to install FBM in the system image file on the system disk. As mentioned above, the kit contains the source and generation files for the RX02 device driver (DYDRV). If you are using the RX02 for FLXIBM you have to include the new driver into your system. If you have not included loadable driver support into your RSX-11/M system you have to regenerate the whole system, if you have loadable driver support, you may use the provided command files to rebuild the driver. GENERATING F L X I B M Page 4-3 4.2 VAX / VMS Systems The FBM utility is distributed on a standard floppy disk only. It contains an object library, an overlay description file and the task-build command files as well as the documentation source files in RUNOFF format. The following is a list of all files on the distribution medium: [SYSUPD] FBMVAX.COM ;Installation command file FBM.EXE ;FBM Image FLXIBM.HLP ;FBM help file FBMVAX.RNO ;Manual RUNOFF file The complete generation process is controlled by the standard VMSUPDATE procedure. Following steps are necessary to install FLXIBM: o Log on to the console terminal under the privileged system manager's account. o Prevent user from logging in into the system by typing: $SET LOGINS/INTERACTIVE=0 o Place the kit volume (FBMVAX01) which contains the FBM distribution kit in your consol Floppy. o Establish the following defaults: $SET UIC [1,4] $SET DEFAULT SYS$UPDATE o Initiate the installation operation by executing the command procedure VMSUPDATE.COM. This installs the FLXIBM utility on your system. If you intend to use FLXIBM from a non-privileged account you have to take additional actions so normal unprivileged users can operate FLXIBM. These are: 1. Every unprivileged user must have the VOLPRO privilege assigned in his user authorization record in order to mount the Floppy with the /FOREIGN qualifier. 2. The System Manager has to modify the user specific startup file SYS$MANAGER:SYSTARTUP.COM to include installation of the AME related shared images: GENERATING F L X I B M Page 4-4 SYS$SYSTEM:RSX.EXE SYS$SHARE:RSXSHR.EXE SYS$SHARE:RSXUSR.EXE 3. The System Manager has to install the FLXIBM utility with amplified privileges so unprivileged users may operate this utility from their private account, i.e.: $MC INSTALL INSTALL>SYS$SYSTEM:FBM.EXE/OPEN/HEAD- _/PRIV=(LOG_IO,PHY_IO) If this images are not installed correctly, FLXIBM can only be operated under a privileged account. If FLXIBM prints the error message FBM -- Unrecoverable floppy I/O error then the above mentioned images are not installed or not installed correctly. CHAPTER 5 INVOKING FLXIBM 5.1 RSX-11/M Systems There are five direct methods for invoking the FBM utility. FBM can also be invoked by means of indirect files. For systems in which utilities are permanently installed, you can use any of the five direct methods. For systems where not all utilities are installed, there are two direct methods invoking FBM. This section describes the five direct methods for invoking FBM. Also included is a brief description of how to invoke a utility that can accept commands from an indirect file. The operator can invoke FBM when the RSX-11M MCR routine prompts for commands. 5.2 Installing FLXIBM in your system RSX-11M systems provided in the distribution kits require the MCR RUN command to invoke a utility. Utilities must be installed permanently in the system before the operator can invoke a utility by its name. To install FBM permanently on the system, use the MCR INSTALL command. MCR commands are described in the RSX-11M Operators Procedures Manual. 5.3 Invoking the permanently installed FLXIBM There are three primary methods for invoking the permanently-installed FBM; this section describes those three methods. Note that the task name of the installed FBM is "...FBM". The solicited input request prompt looks therefore like "FBM>". The name of the task image file is FLXIBM.TSK. INVOKING FLXIBM Page 5-2 5.3.1 Invoking FLXIBM and returning control to MCR Use the following form of command line to invoke FBM to execute a function and then to return control to MCR. >FBM COMMANDSTRING Using this method to invoke FBM allows the operator to enter a single line of commands for execution. FBM is loaded from the device, from which it was installed, the command is executed, and control returns to MCR. The method described below allows the operator to enter more than one command line, because control returns to FBM rather than to MCR. 5.3.2 Invoking and passing control to FLXIBM Use the following form to invoke FBM and to pass control to it: >FBM This form of command does not execute a function; rather, it makes FBM available for execution of more than one function without returning control back to the Monitor Console Routine MCR. When invoked using this form the utility responds with the prompt. FBM> Then you may enter the command string that specifies the function you want to be executed. To terminate FBM and return to MCR, enter CTRL/Z by pressing the CTRL key and the Z key at the same time. Note, that this method forces the executive to keep FBM resident in core as long as it is terminated by CTRL/Z. 5.3.3 Invoking FLXIBM to run under another UIC To invoke FBM to run under another UIC other than the current UIC, use the following command form: RUN ...FBM/UIC=[group,member] This command invokes FBM to run under the specified UIC. When FBM gains control, it prompts for command lines as described in the preceding section. CTRL/Z terminates the utility and resets the UIC to the UIC in effect before FBM was invoked. This procedure is useful, when access rights to a directory, other than the owner, are required. This command can only INVOKING FLXIBM Page 5-3 be executed if the issuing terminal is privileged. NOTE This method of invoking FBM should not be used on multi-user RSX-11M systems under any circumstances. 5.4 Invoking uninstalled FLXIBM There are two methods for invoking uninstalled utilities. These methods are useful for smaller systems where not all utilities are installed. Both methods use the MCR RUN command to bring FBM into memory and give control to it. The first method invokes FBM by means of the following command: RUN $FLXIBM RUN is the MCR RUN command; the dollar sign ($) directs MCR to search the system directory for FBM to bring it into storage. When FBM gains control, it displays the prompt: FBM> and waits for the operator to enter a function for execution. The utility continues to prompt you after each function is executed. To terminate FBM, enter CTRL/Z, which both terminates the utility and removes it from storage. The second method for invoking an uninstalled copy of FBM is the same as the first, except that it allows FBM to run under a UIC other than the current UIC: RUN $FLXIBM/UIC=[group,owner] When the utility gains control, it prompts for functions to execute until the operator enters CTRL/Z, as described in the preceding paragraphs. INVOKING FLXIBM Page 5-4 5.5 VAX / VMS Systems FLXIBM can be invoked on VMS by means of the MCR FBM command. If this command is given to DCL without an argument, then FLXIBM promts with the FBM> prompt. You may, however, initiate FLXIBM in an RSX type fashion, where the commandline itself contains the command to FLXIBM as well. NOTE Before using FLXIBM you must mount the floppy diskette with the /FOREIGN qualifier. Failing to do so may lead to unpredictable results. CHAPTER 6 USING INDIRECT FILES An indirect file is a file containing a sequence of command strings that can be interpreted by a single task, usually a system-supplied task such as a utility, MACRO-11 or the Task Builder. These command strings appear in the indirect file exactly as they were entered from the operator's terminal. The command strings contained in the indirect file are executed when the indirect file is invoked. For example, an indirect file might contain a series of FBM command strings. To invoke such an indirect file, enter the following command: >FBM @COMMANDS.CMD (RSX) or $MCR FBM @COMMANDS.COM (VMS) In this example, FBM is invoked and accesses the file "COMMAND.CMD", which contains the sequence of FBM command strings. FBM executes the commands and returns control to MCR when all command lines in the indirect file are processed. RSX-11M/VMS allows the operator to invoke indirect files directly from the MCR/DCL environmet without first invoking FBM. Such an indirect file may contain command strings for more than one utility and is invoked by entering only the file specification preceded by the "at" sign: >@INDIRECT.CMD (RSX) or $@INDIRECT.COM (VMS) The default values for indirect file specifications are: dev = SY0: uic = The current UIC USING INDIRECT FILES Page 6-2 filename = No default filetype = .CMD version = The latest version of the file For complete information of how to use indirect files, refer to the RSX-11M Operators Procedures Manual. VMS users should refer to the VAX/VMS Command Language Users Guide. CHAPTER 7 FILE SPECIFICATION 7.1 Entering command strings The general format for entering command strings to RSX-11M utilities is: outfile,...outfile=infile,...infile where outfile and infile are file specifications for the output and input files to be operated by the utility. RESTRICTION FBM can operate on one input and one output file specification only. This general format varies from utility to utility; some use the entire command string and others use the abbreviated forms of the command string. The utilities also accept indirect files containing command strings, as described in chapter 4 of this manual. 7.2 Entering file specifiers In the command string format described above, outfile and infile represent file specifications. The number of file specifiers for FBM is limited to one for input and one for output. The maximum length of the file specifier is restricted to 80 bytes. FILE SPECIFICATION Page 7-2 The format for entering file specifiers is: dev:[group,member]filename.type;version/sw.../subsw... where: dev: is the physical device on which the volume containing the desired file is mounted. The name consists of 2 ASCII characters followed by an optional 1- or 2-digit octal unit number and colon. [group,member] is the group and member number associated with the UIC containing the desired file. filename is the name of the file. RSX-11M filenames can comprise up to 9 alphanumeric characters. type is the extension to the filename, which identifies the type of file. The filetype provides a convenient means of distinguishing different forms of the same file. The filetype may be up to 3 alphanumeric characters. version is an octal number that specifies different versions of the same file. Version numbers may range from 0 through 77777 (octal). /sw is a 2-character ASCII name specifying a switch associated with a function to be executed. Switches can take one of three forms: /sw invoke function /-sw negate function /nosw negate function Switches may take arguments in the form of ASCII strings and numeric strings. /subsw is a 2-character ASCII name specifying a subswitch to a switch. FILE SPECIFICATION Page 7-3 7.3 FLXIBM Switches There are 6 switches available with FBM. They are used to identify the file-system on which a file is to be operated and some general actions. The switches have the following meaning and form: /RS File is a FILES-11 structured file /LI List directory in short form /FU List directory in full format /DE Delete a specified file from floppy /IN Initialize a floppy with 3741 structure /HE Print content of help file 7.3.1 Use of the "RS" switch This switch is used to tell FBM what file is to be operated in "FILES-11" mode and what file in "3741" mode. A copy operation from IBM to DEC can look as follows: >FBM DK3:OTTO.MAC/RS=DX:DATEI1 The "/RS" switch is appended to the file specification "OTTO.MAC" in order to declare it as a "FILES-11" file. 7.3.2 Use of the "LI" switch This switch is used to print a directory listing of a "3741" formatted floppy in short form, that is, only the non-deleted file entries. It may have the following form: >FBM DX1:/LI ** DIRECTORY OF DX1: ** HDR1 FILE 1 80 1001 26005 26004 HDR1 FILE 2 80 26005 41007 41006 The example above shows the layout of a directory printout. It provides information about the filename, recordlength, starting track/sector, end of dataset allocation, last track/sector of the file. 7.3.3 Use of the "FU" switch This switch is the same as the "LI" switch, however, it prints a full directory listing including all deleted files. It may have the following form: FILE SPECIFICATION Page 7-4 >FBM DX1:/FU ** DIRECTORY OF DX1: ** HDR1 FILE 1 80 1001 26005 26004 HDR1 FILE 2 80 26005 41007 41006 DDR1 FILE 3 80 41007 56013 56012 The above example shows also the deleted file entries. Note, that DDR1 points out that FILE 3 represents a deleted dataset. 7.3.4 Use of the "DE" switch This switch is used to delete an IBM file from the floppy directory. It is not possible to delete "FILES-11" structured files. It may have the following form: >FBM DX0:IBMFILE/DE The above command deletes the file "IBMFILE" from floppy DX0:. 7.3.5 Use of the "IN" switch This switch is implemented to allow the user to reformat a floppy, which is highly fragmented because of many delete/write functions. In order to format the floppy it is necessary, to rewrite the directory context on the floppy in track 0. Before initializing the floppy you must confirm that you really want to destroy the contents on the medium and answer a question for the volume label string. Great care should be taken in initializing a floppy. Disk resident data will be completely destroyed. After the initialization process the floppy has a standard 3741 formatted directory. However, the floppy is setup with a dataset "DATA", which occupies the whole floppy space. In order to free this space up, you must type the following command: >FBM DX:DATA/DE which makes the floppy available for use now. FILE SPECIFICATION Page 7-5 7.3.6 Use of the "HE" switch This switch is implemented to provide the user with a quick reference to all functions and switches available with FBM. The content of the help file is printed on the requesting terminal. The help file is copied to SY:[1,2]FLXIBM.HLP or SY:[SYSHLP]FLXIBM.HLP as part of the generation process. CHAPTER 8 3741 SPECIALS This chapter is intended to explain some 3741 specials as they are defined by the IBM basic dataset interchange and used by FLXIBM 8.1 Record length The dataset descriptor (directory entry in our terms) of a 3741 floppy specifies a record length of either 80 or 128 bytes. This represents the maximum length a record can have. If a record is shorter, the rest of the datafield is padded with EBCDIC blanks. When FLXIBM reads and converts this records it truncates it to the normal unpadded size and writes the FCS standard variable record format (FD.VAR) to the RSX file. On output to 3741 format FLXIBM padds all records to the maximum record length. FLXIBM looks into the fileheader of the RSX file (max. record size) to determine if it should use 80 or 128 byte records. 8.2 File protection As defined in the IBM specifications two protection fields are provided. The so called "Bypass indicator" and the "Write protect" Field 8.2.1 Bypass Bypass means, that a program, which tries to read the file is not allowed to. If FLXIBM determines this field active (it contains "B")during a read operation, it prints an error message and terminates the function. The bypass can only be turned off and on an IBM or IBM compatible 3741 machine. 3741 SPECIALS Page 8-2 8.2.2 Write protect This field protects an area on the disk (normally a dataset or file) against deletion and reusage by another dataset. As with the bypass field, FLXIBM terminates the function (in most cases a delete) and issues an error message. 8.3 Multivolume datasets A multivolume dataset is a file which is not fully contained on one floppy. It is allowed to be spread over more than one volume. Care however must be taken. The dataset descriptor (directory entry) has a field which contains three possible characters, a blank for no continuation, a "C" for continued and a "L" for last part. If you have floppies containing multivolume files you have to take care about the correct sequence in which the dataset is spread over the volumes. The 3741 format has no sequence numbering scheme to identify the correct order of the volumes. FLXIBM supports multivolume datasets on read, write and delete operations. 8.4 Space allocation The 3741 structure is very simple. On writing a file, there is no check if the dataset would fit onto a particular floppy. If you delete a dataset, there is no check whether the previous or next dataset is also deleted, so the space could be merged to one big deleted dataset. This leads to a fragmentation problem on the floppy if it was used for a long period of time with a lot of dataset creations/deletions. If you run in this fragmentation problem, FLXIBM provides a way to correct it by means of the /IN switch. The floppy resident data, however, will be destroyed, so you have to save all necessary datasets before initializing the floppy. CHAPTER 9 ERROR MESSAGES FLXIBM issues many warning or error messages. This chapter provides a short description of every message and some actions which should be taken if necessary. FBM -- Read bypass on, request killed. The directory entry of this file has the read bypass bit set. You cannot read this file with FLXIBM. FBM -- File protected, request killed The file is protected against reading or deleting. FBM -- Load next floppy and type when ready : This message appears on a multivolume operation during a read, write or delete function. On read or delete the volume sequence number is checked for correctness. You must type CONT in uppercase letters. FBM -- Multivolume transfer terminated This message appears on multivolume operations, if the repeat count is due, the wrong volume loaded, an unrecoverable hardware error occured or the next floppy in the set has not a valid 3741 structure. FBM -- Error reading HELP file This message shows a problem with the help file. Check SY:[1,2]FLXIBM.HLP, if there is any problem with the file. If you cannot read it with PIP, for example, copy the help file from the distribution Floppy. FBM -- Floppy data will be destroyed, confirm with : This is just a confirmation message when you try to ERROR MESSAGES Page 9-2 initialize a Floppy by means of the /IN switch. It tries to warn you that, when you initialize the floppy, all data on it will be destroyed. You must type Y in uppercase letters. FBM -- I allow you to try it again, be careful This is a warning message, which appears on multivolume operations, when you put the next volume in the drive and the sequence number does not match. There is a repeat count which limits the number of wrong tries you have. You can set up this repeat count in FBMBLD.CMD in SY:[1,20] or SY:[1,24]. FBM -- File not found A specified file on RSX volumes or on 3741 volumes has not been found. Reenter correct filename. FBM -- Multivolume DELETE aborted A multivolume delete operation has been aborted, because of a wrong sequence number of one of the volumes. FBM -- Unrecoverable system I/O error A system error has occured during reading or writing an RSX file. Check, if the volume on which this file resides is write enabled and online. It may also be caused by a parity error (bad block) on the device. FBM -- Unrecoverable floppy I/O error In most cases a parity error on the floppy. Try to copy as much as possible files from this floppy and don't use it anymore. The file 3741 file structure does not take care about bad blocks, because physical block relocation is not supported. FBM -- Device already attached by another user The floppy device on which you tried to start an operation is currently used by another user. Try again later or use another drive. FBM -- System error - AT fault ->> restart ! The indirect command file processor has detected an internal error. Restart operation. FBM -- Output device full Either the RSX file device or the 3741 floppy is ERROR MESSAGES Page 9-3 full. Try again with another volume which has enough free space. FBM -- RSX close lun error An error has occured while closing an RSX file. See the I/O reference manual provided with the standard RSX documentation set for more details. FBM -- Invalid IBM 3741 format The floppy which you have mounted in a particular drive does not have the standard 3741 dataset format. Check the floppy, and if possible initialize it by using the /IN switch. FBM -- Duplicate floppy file spec. The file you want to copy to the floppy cannot be entered into the directory because there is a file already on the volume, which has the same name. FBM -- Open failure for RSX - file Most likely an indication, that the file does not exist on the specified RSX volume. FBM -- Operation aborted due to operator request This message appears if you did not confirm the initialization process or a multivolume operation. FBM -- Invalid drive assignment This error message is printed out, when you try to do an 3741 operation on a device, which is not a floppy. It may also point out that you have setup the /IB switch incorrectly.