--- title: "D.U.S. 4.0 Disk Utility System" id: 72133 type: "computer_media" slug: "d-u-s-4-0-disk-utility-system" url: "http://localhost/computer_media/d-u-s-4-0-disk-utility-system/" markdown_url: "http://localhost/computer_media/d-u-s-4-0-disk-utility-system.md" published_at: "2026-10-21T08:01:29+00:00" modified_at: "2026-10-26T20:22:18+00:00" author: "David Anderson" featured_image: url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg" excerpt: "More than thirty disk utilities for LKDOS, from copying, formatting and catalog sorting to block editing and recovering erased files, run from a scrolling boot menu." post_tag: - name: "Byte Power" slug: "byte-power" taxonomy: "post_tag" url: "http://localhost/tag/byte-power/" - name: "Downloadable" slug: "downloadable" taxonomy: "post_tag" url: "http://localhost/tag/downloadable/" - name: "TS 2068" slug: "ts2068" taxonomy: "post_tag" url: "http://localhost/tag/ts2068/" model: - name: "Timex/Sinclair 2068" slug: "ts-2068" taxonomy: "model" url: "http://localhost/model/ts-2068/" indiv: - name: "Kristian Boisvert" slug: "boisvert-kristian" taxonomy: "indiv" url: "http://localhost/indiv/boisvert-kristian/" genre: - name: "Utility" slug: "utility" taxonomy: "genre" url: "http://localhost/type/utility/" media_type: "Diskette" programmers: - name: "Kristian Boisvert" slug: "boisvert-kristian" taxonomy: "indiv" url: "http://localhost/indiv/boisvert-kristian/" download_url: "https://archive.org/download/timex-sinclair-software-archive/D.U.S.%204.0%20Disk%20Utility%20System%20%281989%29%28Boisvert%2C%20Kristian%29%28TS2068%29%28US%29%28Larken%20Disk%29.zip" tsrun_member: "D.U.S. 4.0 Disk Utility System (1989)(Boisvert, Kristian)(TS2068)(US)(Larken Disk)/disk files/BANAL.B1.tap" mediadate: "1989" producer_company: - id: 25181 title: "Byte Power" type: "company" url: "http://localhost/company/byte-power/" article_media: - id: 22742 title: "D.U.S. Disk Utility Software" type: "article" url: "http://localhost/article/d-u-s-disk-utility-software/" related_products: - id: 25185 title: "The D.U.S." type: "product" url: "http://localhost/product/the-d-u-s/" related_content: - id: 72734 title: "Larken System Utility Programs (Larken Edition)" type: "computer_media" url: "http://localhost/computer_media/larken-system-utility-programs-larken-edition/" media_type_tags: "Utility" license: false --- # D.U.S. 4.0 Disk Utility System Gathers more than thirty disk maintenance programs for the Larken LKDOS system on one disk, all run from a single boot menu. It needs a TS2068 with the Larken disk interface and has not been converted for tape. Booting the disk shows a title screen and then `BOOT.B1`, which lists the programs on the current drive as lettered entries A–P, scrolls the list with 6 and 7, switches drives with 0–4 and loads the chosen file with one keypress. Each utility is a short BASIC front end that asks for a drive (99 to quit), calls its machine code to do the work and then goes back to the menu. ## The Utilities The on-screen names of the programs, with their file names, are: - **Copying:** COPY DISK I, II, III and IV (`COPY I.B1`, `COPYII.B1`, `COPY 3.B1`, `COPY 4.B1`); COPY DISK III asks for one to four copies. - **Formatting and setup:** FORMAT DISK, FAST FORMAT, INITIALIZE CATALOG, CHANGE TRACKS & SIDES, FAST CHANGE TRACKS & SIDES, CHANGE HEAD SPEED, CHANGE DISK NAME and COLORED DISK NAME (`FORMAT`, `FASTF`, `INIT`, `TRKSID`, `FTRKSD`, `HEAD`, `DSKNAM`, `COLNAM`). - **Housekeeping:** CLEAN UP DISK, FAST CLEAN UP, FRESHEN DISK, FAST FRESHEN, SORT NAMES (puts the catalog in alphabetical order) and MAP OUT BAD BLOCKS (`CLENUP`, `FCLEAN`, `FRESHN`, `FFRESH`, `SORT`, `MAPOUT`). - **Inspection and editing:** DISK ANALYZER, FILE ANALYZER, BLOCK ANALYZER, BLOCK EDITOR and TRACK MAP EDITOR (`CHKDSK`, `FANALY`, `BANAL`, `BEDIT`, `TMAPED`). - **Recovery:** RECOVER ERASED FILE, RECOVER BAD DISK and RECOVER CATALOG (`RECOVR`, `RECBAD`, `RECCAT`). - **Batch file work:** BATCH MOVE, BATCH ERASE, BATCH RENAME and NAME THIEF, which works between a source and a target drive (`MOVE`, `ERASE`, `RENAME`, `THIEF`). - **Booting:** the `BOOT.B1` menu, the `SCREEN.CS` title screen and `MINIBT.B1`, a “tiny boot for Larken LKDOS” that picks a file from a grid with Q, A, O and P and loads it with ENTER. `BOOT.B1` can be set to show or hide code files in its list. Seven of the programs (CLEAN UP, COPY DISK II, COPY DISK IV, FORMAT, FRESHEN, RECOVER CATALOG and CHANGE TRACKS & SIDES) come with four versions of their machine code, with the endings `.CA`, `.CL`, `.CO` and `.CR`. Each has to be customized before its first use: as found, it stops with “THIS PROGRAM MUST BE CUSTOMIZED!” and lists the line where the owner puts the letter of the version to load. ## Provenance The programs credit Kris (Kristian) Boisvert and Byte Power on screen. Most modules are dated 1989, while COPY DISK III and IV, FAST FORMAT, FAST CLEAN UP, FAST FRESHEN, FAST CHANGE TRACKS & SIDES, RECOVER BAD DISK, BLOCK ANALYZER, BLOCK EDITOR, TRACK MAP EDITOR, FRESHEN DISK and NAME THIEF say 1990, and a REM in `BOOT.B1` still reads 1988. Byte Power sold the package as The D.U.S. for the LKDOS cartridge. This copy comes from a disk labelled “Dus4.0”, which also holds a copy of Bob Swoger’s `L.B1` loader (V4.9L3, 1992) that is not part of the package. The download holds the raw image of the original disk and every file on it as a TAP. The download now also includes the D.U.S. manual, from a separate Larken disk labelled “D.U.D. V4.0 Manual”. It holds Kristian Boisvert’s help texts as 36 Tasword files: a table of contents, a foreword, notes on using the package, and one page for each program. They are joined in `D.U.S. 4.0 Manual.txt` in the order of the manual’s own table of contents, and the original `.CT` files are in the `manual` folder as TAPs. The manual answers the question left open above: the programs that must be customized (COPY DISK II and IV, FORMAT DISK, CLEAN UP DISK, FRESHEN DISK, RECOVER CATALOG and CHANGE TRACKS & SIDES) load the machine code for the owner’s disk cartridge, so the letter typed into `LET A$=""` is “L” for Larken, “A” for Aerco, “R” for Ramex or “O” for Oliger, matching the `.CL`, `.CA`, `.CR` and `.CO` files. The foreword describes D.U.S. as public domain, free to copy for other LKDOS users, with updates and a printed manual available from Byte Power. The manual disk also has each text a second time as a `.Cm` file, apparently for the copy of MScript 5.5 that is also on the disk; these and MScript were left out. Boisvert’s street address and phone number have been blanked in the text and in the two `.CT` files that gave them. ## Source Code ``` 0 REM FORMAT DISK WRITTEN BY K BOISVERT COPYRIGHT 1989 BYTE POWER 10 GO TO 30 20 LET L=USR 65281 30 POKE 23658,0 40 PLOT 0,173: DRAW 20,0: DRAW 0,-3: DRAW -2,0: DRAW 0,-2: DRAW 2,0: DRAW 0,-15: DRAW -20,0: DRAW 0,20 50 CIRCLE 10,164,3: PRINT #4: CIRCLE 3,160,1: PRINT #4: CIRCLE 3,165,1 60 INVERSE 1: PLOT 9,158: DRAW 0,-3: DRAW 1,0: DRAW 0,3: DRAW 1,0: DRAW 0,-3: INVERSE 0 70 PRINT AT 0,10;"FORMAT DISK";AT 1,4;"WRITTEN BY KRIS BOISVERT";AT 2,8;"*1989 BYTE POWER" 80 PLOT 0,147: DRAW 255,0: DRAW 0,1: DRAW -255,0 90 LET l=USR 61337 100 LET A=PEEK 65535: LET DR=0: IF A=4 THEN LET DR=1 110 IF A=8 THEN LET DR=2 120 IF A=16 THEN LET DR=3 130 IF A=128 THEN LET DR=4 140 PRINT #4: GO TO DR: PRINT #4: LOAD "BOOT.B1" 150 INK 0: PAPER 7: BORDER 7: CLEAR 44999: RANDOMIZE USR 100: OPEN #4,"DD" 160 LET a$="": IF a$="" THEN PRINT AT 5,0;"THIS PROGRAM MUST BE CUSTOMIZED!"''': BEEP .25,0: BEEP .25,0: LIST 160: STOP 170 PRINT #4: LOAD "FORMAT.C"+a$CODE : RUN 20 9999 RANDOMIZE USR 100: SAVE "FORMAT.B1" LINE 150 ```