File: FUTIL.TX of Disk: Disks/PDP8-Net/diag-games-kermit
(Source file text)
FFFFFFF UU UU TTTTTTTT II LL
FF UU UU TT II LL
FFFF UU UU TT II LL
FF UU UU TT II LL
FF UU UU TT II LL
FF UUUUUU TT II LLLLLLL
OS/8 File UTILity program
Jim Crapuchettes
MENLO COMPUTER ASSOCIATES
(formerly FRELAN ASSOCIATES)
P.O. Box 298
Menlo Park, Calif. 94025
Futil Version 6.16
Writeup Version 6.5
March 1977 Page i
FUTIL - OS/8 File UTILity program
NEW FEATURES
This version of FUTIL represents a significant revision and
expansion over the previous version. The following is a capsule
summary of the changes and new features of this version:
1. Chaining support and CCL command addition for convenient setup
and startup. Restartable even after CCL command setup.
2. Addition of F4 support in the form of FPP instruction decoding
and .LD module mapping and header decoding (including overlay
specification).
3. Future MACREL/LINK support in the form of overlay
specification support for .SV files and extension of CCB
decoding for overlay information.
4. DIRECTORY output format to help in decoding crashed
directories and COS format for examination of COS-300 data
files.
5. SCAN command to do rapid check for read errors on the current
device.
6. Defaults of .SV, .LD and null for FILE command.
7. Modification to "limit" options for WORD and STRING commands
for more convenient usage.
8. FILLER variable, used by MODIFY command to fill in specified
words whose new contents are not given.
9. Additional output of VERSION, by itself and with ERRORS.
10. Several changes to command names and syntax for more logical
usage.
11. Swapping of error messages or write-locked operation (without
error messages), as needed.
12. Absolute block number display in MQ register (if available).
13. Order of magnitude improvement in performance for WORD and
STRING search commands; WORD is now as fast as SCAN!
These new features are paid for by a reduction of the IOT
table expansion area from 64 to 32 IOTS and by error message swapping
with the USR.
March 1977 Page ii
FUTIL - OS/8 File UTILity program
Acknowledgements
First, thanks need to go to Tom McIntyre of West Virginia
University for the use of RUNOFF for the generation of this manual.
The significantly increased readability of the manual is directly due
to the formatting, paginating and case conversion capabilities of
RUNOFF.
I want to especially thank several people who read this
writeup and commented on it and the program. Tim Clarke, one of my
associates, reviewed this writeup many times during its growth. Jim
Warren, currently editor of DR. DOBBS JOURNAL, and John Tubbs,
currently at the Palo Alto VA Hospital, each made many helpful
comments on the writeup. Dennis McGhie, currently at Stanford
Research Institute in Menlo Park, made several suggestions on possible
additions to the program, the error messages in particular. All of
these people were associated with Stanford University or Stanford
Medical Center during the time that I worked at Stanford. Also not to
be forgotten are many other users who made comments and suggestions
during the time that this program has been developing.
I also want to mention the groups whose computers were used in
the development of this program. The original program, XTAPE, was
developed on the PDP-8 belonging to the Tropospheric Propagation Group
of Stanford Electronics Labs. Most of the work on FUTIL Version 5 was
done on the PDP-8/E belonging to the Department of Anesthesia at the
Stanford Medical Center. The rest of the work on FUTIL Version 5 and
work on Version 6 was done on the PDP-12 belonging to the Department
of Cardiovascular Surgery at the Stanford Medical Center, on the
PDP-8/E belonging to the Department of Chemistry at Stanford
University and at whatever other computer I could find.
March 1977 Page iii
FUTIL - OS/8 File UTILity program
TABLE OF CONTENTS:
Introduction
Why bother with FUTIL? . . . . . . . . . . . . 1
Running FUTIL (including CCL) . . . . . . . . 3
Special characters used in this writeup . . . 5
Special characters used in FUTIL . . . . . . . 5
Access method . . . . . . . . . . . . . . . . 7
Referencing words on the device . . . . . . . 9
Numeric items (or numbers) . . . . . . . . . . 10
Errors (and error messages). . . . . . . . . . 11
Single character (ODT-like) commands . . . . . . . . . 12
"Symbolic" output formats . . . . . . . . . . 14
Word-type commands . . . . . . . . . . . . . . . . . . 16
Output formats . . . . . . . . . . . . . . . . 17
DUMP . . . . . . . . . . . . . . . . . . . . . 18
LIST . . . . . . . . . . . . . . . . . . . . . 19
MODIFY . . . . . . . . . . . . . . . . . . . . 20
Search limits . . . . . . . . . . . . . . . . 23
WORD (search) . . . . . . . . . . . . . . . . 23
STRING (search) . . . . . . . . . . . . . . . 24
SMASK . . . . . . . . . . . . . . . . . . . . 25
SET . . . . . . . . . . . . . . . . . . . . . 27
SHOW . . . . . . . . . . . . . . . . . . . . . 28
FILE . . . . . . . . . . . . . . . . . . . . . 31
WRITE . . . . . . . . . . . . . . . . . . . . 32
SCAN . . . . . . . . . . . . . . . . . . . . . 32
REWIND . . . . . . . . . . . . . . . . . . . . 33
EXIT . . . . . . . . . . . . . . . . . . . . . 33
EVAL . . . . . . . . . . . . . . . . . . . . . 34
Additional examples . . . . . . . . . . . . . . . . . 36
Miscellaneous information
Assembling, loading & CREFing the program . . 43
Program execution and memory allocation . . . 43
List device output . . . . . . . . . . . . . . 45
Implementation notes . . . . . . . . . . . . . 45
Command summary . . . . . . . . . . . . . . . . . . . 48
Single-character command output format summary . . . . 49
March 1977 Page 1
FUTIL - OS/8 File UTILity program
INTRODUCTION:
Why bother with FUTIL?
----------------------
The most obvious answer is that you want or need to use it!
This immediately leads to the question: What does it do? FUTIL
enables a user to examine and modify from the console terminal the
contents of mass storage devices for which an OS/8 handler is
available. It is the only program currently available which can be
used to patch programs which contain overlays (MACREL/LINK or F4/LOAD
outputs). Other possible uses include: application of patches to
system programs as reported in Digital Software News; examination and
repair of clobbered OS/8 directories; bad block checking and fixup on
a device; decimal/octal conversion of double precision numbers; output
of the CCB of ".SV" files and the HEADER of ".LD" files; examination
of non-OS/8 devices; creation of special directories. Its closest
relatives in the form of DEC-supported software are ODT and EPIC. ODT
is not used for patching files on devices, however, so the
relationship is in form and philospohy. EPIC can patch files on
devices and can also compare files (see OCOMP by Dennis McGhie for
those comparisons and device independent output that you really wish
EPIC would do) and output special paper-tapes of files (if you can't
get by with a simple SV2BIN program, at least one of which has been
floating around for some time, you'll have to use EPIC). However,
though FUTIL does not do comparisons or punching, it does a much more
convenient job of patching files on devices, including over thirty
(30) commands with many options, four (4) accessing modes for the
device, four (4) data input formats, two (2) searches, eighteen (18)
status and information outputs and twelve (12) output formats, all of
which allow for easy examination of words or blocks on a device in the
most understandable way. Supporting these functions is signed
double-precision arithmetic expression evaluation which can be used by
itself (ever try to convert -135748 to octal?) or in any place in the
command syntax that a numeric value is needed.
Two simple examples at this point may entice you to read
further. Assume that you would like to know what CCL remembers of
your last ".UA" command. The remembrances are stored on block 65
(octal) of the system device. As described in the source of CCL, each
of the remembrances is allocated 40 (octal, 32 decimal) words in this
block, the first four of which contain binary information and the last
34 of which contain the last input command, stored as packed ascii
characters. The lines contain the inputs for the commands as follows:
TECO and MAKE (line 0), EDIT and CREATE (line 1), COMPILE and EXECUTE
and PAL (line 2), UA (line 3), UB (line 4), UC (line 5), and,
possibly, FUTIL. So the saved ".UA" command can be listed by
outputting the contents of the 4th through 37th words of area 3 in
block 65 as packed ascii characters as follows--
.R FUTIL<cr> --call FUTIL from OS/8
EVAL 3*40+4<cr> --calculate start displacement
= 00000144 ( 0000100) -- of the 3rd "line" (=144[8])
March 1977 Page 2
FUTIL - OS/8 File UTILity program
INTRODUCTION:
now list the words of this line with the LIST
command, specifying the output format to be PACKED
ascii characters and the words to list to be block
65 locations 144 (from above) through 144+33 (the
expression for the location of the last word of
this "line"). FUTIL responds with the start
location and a line characters, and the next
location with a multiple of 10[8] as an address
and a line of characters.
LIST PACKED 65.144-(144+33)<cr> --list the words wanted
0065.00144: DIR R:FUT???.*/E/R=3
0065.00160: --that's it!
NOTE on <cr>
For the examples above and below, the symbol "<cr>"
is used to show that you need to terminate your
command lines with a "carriage return". All other
lines above are output by the program.
Now lets assume that you would like to make the simple patch
for OS/8 FORTRAN IV users with an FPP-8/A to use the lockout feature
of the FPP-8/A, as given in the August 1976 Digital Software News.
This requires changing the contents of location 15776 of FRTS (the
Fortran Run Time System) from 400 to 410 (which adds the lockout bit).
After doing this you also want to update the date word of the
directory entry for FRTS (the 4th word beyond the start of the entry)
to show that the file has been updated. You would do the following--
.R FUTIL<cr> --call it
SET MODE SAVE<cr> --set FUTIL to a mapped mode
FILE FRTS<cr> --look up the file to map
FRTS.SV 0671-0722 0032 (0026) 1.327 12/31/75
--"1.327" is start of entry!
Now use "ODT" command "/" to open and change 1
word.
15776/ 0400 410<CR> --add LOCKOUT bit
SET MODE NORMAL<cr> --switch to unmapped
now use "ODT" command "/" with an expression to
open the date word, command "@" to output it in
"date" format and then put today's date (as an
expression) in its place!
March 1977 Page 3
FUTIL - OS/8 File UTILity program
INTRODUCTION:
1.(327+4)/ 6375 @12/31/75 (D)<CR> --change file date
WRITE<cr> --send out this change
NOTE on device access
First the file FRTS.SV is changed, and then the OS/8
directory is updated to the current date. Changing
the address desired from FRTS to the directory
automatically writes out the modified block of FRTS
before reading in the directory segment that
contains the file name. However, the changed
directory segment must be written out explicitly
because there are no other blocks to examine for
this example.
The command set of FUTIL is divided into two groups of
commands, as seen above. The first group uses single letters to
direct the program in the examination and modification of single words
on the device. These commands are very similar to the commands used
by OS/8 ODT in both form and function. Examples would be "/", "+" and
";". The second group of commands uses command words to direct the
program in the dumping, listing, modifying and searching of the device
more or less on a by-block basis. Also included in this group is a
set of commands to direct the program in some auxiliary functions
including setting and resetting switches and variables within the
program, showing their settings and values, etc. Examples of these
would be 'DUMP', 'SET' and 'EVALUATE'.
Running FUTIL (including CCL):
------------------------------
FUTIL can be called into execution by either the OS/8 Monitor
commands "R FUTIL" (as seen above) or "RU dev:FUTIL" or by the CCL
command "FUTIL ...", which may optionally include the specification of
a device name and/or a file name (with optional extension) and/or
several switches. The CCL command is an addition which requires that
the standard version of CCL be modified. When execution begins due to
an "R" or "RU ..." command, FUTIL performs some initialization
(described in more detail in the section on program execution), types
a carriage-return and line-feed and is at your command. When
execution begins due to the CCL command, FUTIL performs the same
initialization, loads any device handler requested, acts on any
switches given, performs a 'FILE' command if a file name is specified
(with output as described for this command) and is at your command.
When started without further direction, FUTIL is set up to
access the system device, the 'ERROR' message output mode is set to
'LONG', the access 'MODE' is set to 'NORMAL' and no file is known. To
March 1977 Page 4
FUTIL - OS/8 File UTILity program
INTRODUCTION:
access some other device, either use the CCL command and specify the
name of the device desired (including a ":") or give the command 'SET
DEVICE dev' (without a ":"). To set the 'ERROR' mode to 'SHORT',
either add "/E" to the CCL command, or give the command 'SET ERROR
SHORT'. To use some other access mode, either add a mode switch to
the CCL command ("/L", "/O" or "/S") or give a 'SET MODE <mode>'
command with a <mode> of 'LOAD', 'OFFSET' or 'SAVE' (note switch to
mode correspondence). When in 'OFFSET' mode, the 'OFFSET' to be used
can be specified by either adding "=oooo" to the "/O" added to the CCL
command, or the command 'SET OFFSET oooo' can be given. Lastly, a
file lookup can be done either by adding a file name to the CCL
command or by giving a 'FILE' command (with three default extensions).
The following is a summary of the options of the CCL command
for FUTIL:
.Futil [dev:][file[.ex]] [/E][<mode switch>]
where only the first character of the command must be given but any
other, if specified, must be correct (the standard for CCL commands)
and where the <mode switch> can be one of the following:
/L set: access mode to LOAD, default .ex to .LD only
/O=oooo set: access mode to OFFSET, offset to "oooo"
/S set: access mode to SAVE, default .ex to .SV only
Finally, when using the CCL command, CCL remembers the command
line, requiring the desired options to be entered only once per day
until it is desired to change them. To call FUTIL with no options and
without using a previously entered command, add an unused switch (such
as "/X") to the command.
NOTE on second example above
The use of this extension to CCL would have somewhat
simplified the second example given previously
because the command string "FUT FRTS/S" would have
called FUTIL, 'SET' the 'MODE' to 'SAVE' and
executed the 'FILE' command, all in one swoop!
Information on addition of this command is provided in the
source of the patch file FUTCCL.PA which is provided with the other
FUTIL release files.
March 1977 Page 5
FUTIL - OS/8 File UTILity program
INTRODUCTION:
Special characters used in this writeup:
----------------------------------------
To help reduce the confusion brought about when this writeup
is output in upper case only, the characters single quote ('), double
quote ("), angle brackets (< and >) and square brackets ([ and ]) have
been used to help separate special items from the words around them.
The single quote character is used to surround a word-type command,
e.g. the 'FORMAT' option 'SET's up the format in which output is to be
done. The double quote is used to surround an item whose actual name
is being used, e.g. the "RETURN" key is the key on the Teletype that
has that word printed on it. The angle brackets are used to surround
the name of a type of item (a syntactical type), e.g. "<n>" means that
a NUMERIC ITEM is to be used. The square brackets are used to
surround optional items, e.g. "w[ord]" would indicate that the
characters "ord" may be supplied optionally.
Special characters used in FUTIL:
---------------------------------
Several characters, when keyed, cause immediate action from
the program. Typing either "CTRL"-"P" (which prints "^P") or
"CTRL"-"C" (which prints "^C") will immediately cause the program to
stop whatever it is doing. "CTRL"-"P" then causes the program to go
back to command input mode and wait for you, while "CTRL"-"C" calls
the OS/8 Monitor (as it does with most system programs).
During console terminal input, three other keys can be used to
help with editing the input string of characters. These keys are
"RUBOUT", "CTRL"-"U" (which prints "^U") and "CTRL"-"R" (which prints
"^R"). The action of "RUBOUT" and "CTRL"-"U" is exactly the same as
it is for the OS/8 Monitor and Command Decoder. The action of
"CTRL"-"R" is the same as that of the "LINE-FEED" key for the Monitor
and Command Decoder (a different key was required due to the fact that
"LINE-FEED" is used for other things in this program so the key picked
is the same one used by TOPS-10 for this function).
For those users with upper-lower case terminals, the program
translates all lower case characters received from the keyboard to
upper case. The characters are echoed and handled internally as upper
case characters. While this makes use easier, it obviously does not
allow any lower-case characters to be input directly. In those cases
where lower-case codes are needed in the modification of a file,
either use the codes directly or use a text editor. Note that this
translation occurs only on input! Lower case characters in a file
will be printed to the best ability of the output device.
All of the commands are taken in context, i.e. many of the
characters which are used in the single character command set will not
be considered to be commands if they are included in a line which
March 1977 Page 6
FUTIL - OS/8 File UTILity program
INTRODUCTION:
begins with a command word or if they are embedded within expressions.
The carriage-return ("RETURN") always starts command
execution, and is the terminator for all word-type command lines.
March 1977 Page 7
FUTIL - OS/8 File UTILity program
INTRODUCTION:
Access method:
--------------
The program accesses the OS/8 device one OS/8 block (256
words) at a time. For every location specified, the real block and
word are determined and compared with the current block in memory. If
the desired block and current block are not the same, the
<something-changed> flag is checked to see if anything has been
changed in the current block. If nothing has been changed, the new
block is read in. If something has been changed, the current
(modified) block is first written out and then the new block is read
in. This action happens correctly even when the access mode is
changing because it is done at the level of the OS/8 block number
right before calling the current 'DEVICE' handler.
The contents of the OS/8 device are therefore not changed
unless the block in which changes are made is written out either
implicitly, as described above, or explicitly, using the 'WRITE'
command (which is discussed near the end of the section on word-type
commands). The result is that typing "CTRL"-"C" before writing out
the current block (assuming it has been modified) will return to the
Monitor without actually modifying the contents of the device itself.
Note, also, that only one implicit write attempt is ever made by the
program. Should an error occur when the write is attempted (e.g.
write locked device), an explicit 'WRITE' command must be given to
actually write out the block.
If the words within some block are changed accidentally, the
<something-changed> flag can be reset by using the 'SET' command to
reset the 'DEVICE' (described further along in this writeup) to the
same device currently being used. This will reset the
<something-changed> flag, the current block in memory, and the file
start block and core-control-block/header-block (if they had been set
by a 'FILE' command). The resetting of the current block in memory
will cause the next access to the device to read in the block desired.
The resetting of the file information will require a new 'FILE'
command to be given to set it back up. If you can't remember what is
the current setting of the 'DEVICE', use 'SHOW DEVICE' first and then
'SET' it the same.
Files stored on an OS/8 mass-storage device generally fall
into one of four categories. The program has four corresponding modes
for accessing the device. The current 'MODE' of the program can be
set by the 'SET' command or by chaining (as described previously) and
examined by the 'SHOW' command (to be described later).
The three categories and their corresponding modes are:
1) General (binary, ascii and data) files - 'NORMAL' mode
2) Core image (save) files - 'SAVE' mode
3) FORTRAN IV load modules - 'LOAD' mode
4) System overlays - 'OFFSET' mode
March 1977 Page 8
FUTIL - OS/8 File UTILity program
INTRODUCTION:
The actual operation of the program for each of these modes is
as follows:
'NORMAL' The high order 7 bits of the 15 bit address are added
to the current block number to get the actual block
number. The low 8 bits of the 15 bit address are used
to specify the desired word within that block.
'SAVE' The file to be examined must be set up by a 'FILE'
command. "Block" numbers are used to specifiy an
overlay number (future MACREL/LINK support) and must
be exactly zero ("0") for files without overlays
(generated by the monitor "SAVE" command). The core
segment data (pages and fields) from the file's CCB
(core-control-block) is used to determine where on the
device the desired word is to be found. This is done
by first determining the correct block from the file's
CCB and then using the low 8 bits of the address to
specify the desired word within that block.
Specifying a nonexistent address or overlay for one of
the single-character (ODT) commands will cause an
error. Specifying a nonexistent address or overlay
for any of the word-type commands will cause the
program to ignore the address and access no data.
'LOAD' The file to be examined must be set up by a 'FILE'
command. Block number specifications are actually
taken as overlay specifications and must be contained
within the file. The information from the OIT
(overlay-information-table) in the header block of the
file is used to determine where on the device the
desired word is to be found. Nonexistent addresses
are handled the same way as for 'SAVE' mode.
'OFFSET' The 12 bit 'OFFSET' (which is set by the 'SET' command
or by chaining with "/O=oooo" and examined by the
'SHOW' command) is subtracted from the low order 12
bits of the address and then the same arithmetic as
with the 'NORMAL' mode is used. This mode is used
mostly with system overlays whose start block number
and actual loading address is known. By setting the
'OFFSET' to the loading address (which can only be a
12 bit number), the 12 bit "actual" addresses of the
overlay can be used.
The 'SAVE' and 'LOAD' modes are mentioned together throughout
this writeup as MAPPED modes because their method of address
translation uses a descriptor block from the file of interest to
control access to the file in a non-contiguous manner.
March 1977 Page 9
FUTIL - OS/8 File UTILity program
INTRODUCTION:
NOTE on block number display
For all access modes, the OS/8 "actual" block number
for the block to be read is stored (for display) in
the computer MQ register (if present). The value is
stored before checking if the current block needs to
be written. It is particularly useful for following
the progress of the 'SCAN' command.
Referencing words on the device:
--------------------------------
The words on the OS/8 device are referenced by their
<location> (often abbreviated as <l>). This <location> consists of an
optional <block> or <overlay> number (which must be followed by a "."
if present), and an <address> or <displacement>. The
<block>/<overlay> number is a 12-bit number which must be in the range
0 thru 7776 (octal), or 4094 (decimal). Block number 7777 (or 4095,
decimal) does not exist under OS/8, and the program will ignore this
number. The <overlay> number is further limited to the number of
overlays at a given address. Whenever the <block>/<overlay> part of
the <location> is not used, the program will use the last specified
value. The <address>/<displacement> is a 15 bit number (5 octal
digits), but leading 0's need not be specified. Thus the forms are:
<block>.<displacement> e.g. 1201.37524
or
<overlay>.<address> e.g. 3.57633
or
<address> e.g. 15721
or
<displacement> e.g. 223
NOTE of caution on device handlers
Neither this program nor the OS/8 handlers generally
include checking for legal block numbers! It is
simply assumed that all accesses to the device will
be done after checking with the directory for legal
file start blocks and lengths, which is the normal
mode of operation under OS/8. This can have very
interesting results with this program, e.g. the
RK8/E handler, given a block number greater than
6257 (octal) on device RKA0, will simply continue on
into device RKB0! Use some (or MUCH) caution!
For the rest of this document, unless otherwise stated, block
will mean <block> or <overlay> and address will mean <address> or
March 1977 Page 10
FUTIL - OS/8 File UTILity program
INTRODUCTION:
<displacement>, depending on usage. Therefore the definition will be:
[block.]address = <location> = <l>
Since these location references are numeric input, all of the
characteristics described next can also be used when specifying
locations.
Numeric items (or numbers):
---------------------------
Two switches are used by the program to allow the input of
either octal, decimal or mixed numeric input where ever numeric input
is used. Each new command line always resets the input mode to octal.
The character "CTRL"-"D" (printed as "^D") switches the input mode for
any following input to decimal. The character "CTRL"-"K" (printed as
"^K") switches the input mode back to octal. These two switches may
be located anywhere in numeric input.
For example, when inputting a string of numbers, the input
would be alternately decimal and octal if it were
^D100,^K100,^D200,^K200,^D300,^K300
Two other characters, double quote (""") and single quote
("'"), may be used for numeric input. The double quote functions the
same way in this program as it does in PAL8--the 8-bit ascii value of
the following character is used as a number. As with all character
input, the special characters described earlier cannot be used. The
single quote functions in a way similar to the way that the "TEXT"
pseudo-op operates in PAL8--the following two characters are masked to
6-bits each and packed into a 12-bit word. There must always be
exactly two characters following the single quote. If it is desired
to pack one half of the word with a 6-bit 00, use the character "@".
For example, a string equivalent to the file-name "PIP.SV" would be
represented by the string
'PI,'P@,0,'SV
Expressions may also be used for numeric input when enclosed
in parentheses. The parenthesis pair "(" and ")" must surround the
expression. When this is so, all the options of the 'EVAL' command
are available for numeric input. For example, the contents of the
switch register can be used for a number by the expression "(S)", or
the current block number + 5 could be used by the expression "(B+5)".
See the discussion of the 'EVAL' command for the other options
available.
March 1977 Page 11
FUTIL - OS/8 File UTILity program
INTRODUCTION:
NOTE on expressions
"(" and ")" must completely surround the expression!
Neither digits nor the switch characters may be
outside of the parentheses or an error will result.
This is required because many of the non-alphabetic
characters have multiple meanings (commands or
operators) so the use of the parenthesis pair
"(...)" provides the necessary context to remove
ambiguity.
Errors (and error messages):
----------------------------
Whenever the program recognizes an error of some type, it
outputs out an error message to inform you what went wrong. The
message tells both what went wrong and where in the command line the
error was made. Depending on the setting of the 'ERROR' mode switch,
either 'SHORT' or 'LONG' messages are output.
The error messages have the forms:
"?<ee> at <cc> <error message>" -'LONG'
or
"?<ee> at <cc>" -'SHORT'
where <ee> is the error code, <cc> is the number of the column in the
command line where the program stopped scanning and <error message> is
the message itself. There are currently 45 error conditions with
corresponding codes and messages to assist the user of this program.
The error codes and their messages can be printed out by the 'SHOW'
'ERRORS' command. The 'ERROR' mode is set by the 'SET' command or by
chaining with "/E" set.
The error messages are swapped with the USR, but not in the
normal manner, allowing write locked startup with the loss of the
message text (see the section on program execution for more
information).
March 1977 Page 12
FUTIL - OS/8 File UTILity program
SINGLE CHARACTER (ODT-LIKE) COMMANDS:
These commands allow the examination and modification of words
on an OS/8 device in the same way that ODT allows the examination and
modification of the memory in the computer.
In all of the following commands where <n>--a numeric item--is
specified, the operation of "closing" the location is to place the
value of <n> into the word if it is open. If the current location is
not open, or if <n> is not specified, no change takes place. Refer to
the "Introduction to Programming" (DEC handbook) and the OS/8 Handbook
sections on ODT for more information if needed. Note that (as
mentioned previously) "[<n>]" with the following commands means that a
numeric item may be optionally supplied.
<l>/ Open & output the contents of location <l> in the
current 'OUTPUT' mode.
/ Re-open the last location opened by one of these
commands and output its contents in the current
'OUTPUT' mode.
[<n>]# Close the current location, re-open it and output its
contents in 'BCD' (3 digit binary-coded decimal).
[<n>]$ (dollar sign) Close the current location, re-open it and output
its contents in 'OS/8' ascii.
[<n>]% Close the current location, re-open it and output its
contents in 'BYTE' octal (8 bits with OS/8 packing).
[<n>]& Close the current location, re-open it and output its
contents in 'COS' format packed ascii.
[<n>]: Close the current location, re-open it and output its
contents in 'SIGNED' decimal.
[<n>]< Close the current location, re-open it and output its
contents in 'OCTAL'.
[<n>]= Close the current location, re-open it and output its
contents in 'UNSIGNED' decimal.
[<n>]> Close the current location, re-open it and output its
contents in 'PDP' (symbolic).
[<n>]? Close the current location, re-open it and output its
contents in 'DIRECTORY' format [negated DECIMAL, DATE
and PACKED (ascii)].
[<n>]@ Close the current location, re-open it and output its
contents in 'DATE' format ("mm/dd/yr", 2 digits each).
March 1977 Page 13
FUTIL - OS/8 File UTILity program
SINGLE CHARACTER (ODT-LIKE) COMMANDS:
[<n>][ Close the current location, re-open it and output its
contents in 'ASCII'.
[<n>]\ Close the current location, re-open it and output its
contents in 'FPP' (symbolic).
[<n>]] Close the current location, re-open it and output its
contents in 'PACKED' ascii.
[<n>]$ ("ALT-MODE" or "ESCAPE" keys) Close the current location,
re-open it and type its contents as specified by the
current 'FORMAT'.
[<n>]"RETURN" Close the current location.
[<n>]; Close the current location and open the next
sequential location. Neither address nor contents are
output, but one space is echoed.
NOTE on use of ";" command
The ";" command can be used to advance through
addresses without outputting their value in octal
when some other format is really more helpful. For
example, when examining a directory, the file name
and extension can be output u )@`4^l\;w_o^):qs_9)lQr-P( 4^Z&=i^ApMawWas(rH;rE:j3Df).7G`g&L"^`w:>Kd(x<MBNreiMr(agq]ry/