home *** CD-ROM | disk | FTP | other *** search
-
- DU-V77.DOC
- by Ward Christensen
- with additional notes by Ron Fowler and Keith Petersen
- (revised 7/23/81)
-
- HOW TO USE DU ver 7.7 DISK UTILITY
-
- INSTALLATION:
- The 7.0 and later versions of DU are designed to
- be installed with a minimum of trouble. In fact, in al-
- most all cases, no changes to the source file should be
- necessary to get DU up and running. This is because DU
- uses the disk paramter block of CP/M to determine the
- characteristics of the disk environment. (see the dis-
- claimer for certain non-standard versions of CP/M 1.4).
- The only parameter that should need to be changed
- will be the clock speed flag at 103H. Leave this byte
- zero if you have a 2 mhz clock. Patch it non-zero for
- 4 mhz. This is only needed for the "Z" (sleep) command.
-
- USE:
-
- Any valid command string may be placed as an
- operand of the original DU command, i.e.:
-
- A>DU G0;D;G2;=OK<D><A><1A>;D
-
- Functions supported:
-
- Tnn Seek to track nn (no read)
- Snn Position to sector nn, and read
- Gnn Position to group nn and read.
- G Shows current position
- V Views the current sector.
- (assumes ASCII data)
- Vnn Views nn sectors
- Fname print directory for file "name",
- then positions to its directory
- sector. (Won't position under
- CP/M 2.x, but see = command below.)
-
- =string Ascii search, starting at current
- sector. <xx> hex may be imbedded,
- or used alone: To find "IN 0FEH":
- =<db><fe>
- Ignores bit 7 unless <xx> is used.
-
- L Re-logs in the current disk. You may pull
- out a disk, put in a new, and "L" just
- to log it in.
-
- Lx Logs in disk 'x', such as: LB
-
- Ux Logs user 'x' for next F command. Gives
- '?' error if not CP/M version 2.x.
-
- D Dump sector, hex + ASCII
- A Dump sector, ASCII only
- H Dump sector, hex only
-
- note all dump commands (D, A, H) may be optionally
- followed by a starting and ending address:
- D0,7F is the same as just D
- D3,5
- A20,3F
-
- CHaddr,val,val,val... change hex in sector
- CAaddr,char string... change ASCII in sector
- NOTE that <xx> may be hex imbedded
- in the Ascii: ca0,OK<d><a><1a>
-
- ----> Use W to write changes to disk.
- Note that the C command echoes
- the overlaid data for verification.
-
- CHaddr-addr,byte
- or CAaddr-addr,byte repeats a change
-
- + advance 1 sector (if below track 2,
- this advances to next numerical, if
- 2 or >, advances based on CP/M's normal
- sector scrambling algorithm, i.e. so +
- will get the next logical sector of the file
-
- - backs up 1 logical sector
-
- Note + and - may take an amount:
- for example, +F steps in 15 sectors.
-
- Note also that "-" issued at the first logical
- sector of the disk will wrap back to the last.
- Further, "+" issued at the last sector will
- wrap forward to the first.
-
- ? Gives command summary
-
- # Prints the disk parameters
-
- M Dumps a map of the group allocations
- for files.
- Mn Shows which file is allocated to
- group "n".
-
- N Resets CP/M via the BDOS. This may
- make it possible under some implementations
- of CP/M to change the disk format (e.g., density,
- sides, etc)
-
- R Reads the sector currently positioned to
- into memory. Note R (Read) is implicit in
- the G, +, and - commands, but N-O-T in the
- S and T commands (I did it because I was
- tired of disk reading after T command before
- I had a chance to issue the S command)
-
- W Write back the current sector (N-O-T-E may
- not be used after an F command, as CP/M was
- used to find the file in the directory
-
- X Exit back to CP/M (Must press return). Ctl-c
- was too easy to hit over modem lines, so I
- decided on 2-byte (X, CR) to exit.
-
- P Toggle printer switch on/off
-
- Y Yanks current sector into sequential memory and
- prints ending address. This allows sectors to
- be written sequentially into memory starting at
- 3000H, for later recovery by DDT, etc.
-
- Z Sleep - causes the program to pause, such
- as to look at a dump. Z is 1 sec. Znn
- is nn tenths of a second on a 2 MHz 8080.
-
- < Saves current sector in a save buffer
-
- > Gets saved buffer. < and > may be used
- to move a sector to another place.
-
- / Repeats entire command. Defaults
- or /nn to "forever". NN may be 2 to 65535
-
- multiple commands may be separated by ";"
-
- Example: the following commands will erase the
- b disk directory to all E5's:
-
- lb log in b drive
- g0 position to dir.
- ch0-7f,e5 fill with e5
- < save the sector
- >;w;+;/16 restore, write, next,
- repeat 16
-
- ----This could be shortened to:
-
- lb;g0;ch0-7f,e5;<
- >;w;+;/16
-
-
-
- INTERPRETATION OF DIRECTORY DATA PRESENTED BY THE DU PROGRAM
-
-
- The following explains the format of a CP/M directory entry
- as shown by DU, using either the "F" (find file) command,
- or just doing "D" (dump) of the directory sectors, which
- are located in groups 0 and 1 on a single density disk.
- ----------------
- Sample result of "FSID.COM" command:
-
- 40 00534944 20202020 20434F4D 0000003A *.SID COM...:*
- 50 33343536 3738393A 00000000 00000000 *3456789:........*
-
- First line -
-
- 40 00534944 20202020 20434F4D 0000003A *.SID COM...:*
- || ||| | || || | |
- || ||^----hex file name-----^ || || ^file name^
- || || || || in ASCII
- || || extent-^^ ||
- || || ||
- || || file size in sectors-^^
- || ||
- || ^^-00 = file active
- || E5 = file erased
- ^^-displacement of line in directory sector
-
- Second line -
-
- 50 33343536 3738393A 00000000 00000000 *3456789:........*
- | |
- | |
- ^---allocation group numbers-------^
-
- END
-