Question 1

MS-DOS drive letters and addressing capacity: DOS uses letters of the English alphabet (A: to Z:) to designate disk drives. How many different drive letters can DOS recognize in total?

Accepted Answer

Introduction / Context: DOS-era systems assign alphabetical letters to identify storage devices. Understanding the total addressable set of drive letters helps technicians reason about multi-drive setups, network mappings, RAM disks, and optical drives in legacy environments and emulations. Given Data / Assumptions: DOS uses single letters followed by a colon (for example, A:, C:, D:). The English alphabet has 26 uppercase letters. Letters are a naming convention; the underlying devices can be local, removable, or network drives. Concept / Approach: Count the available symbols used by DOS to label logical volumes. Each letter corresponds to a potential logical drive. Historically, A: and B: are often reserved for floppy drives, and C: typically denotes the first hard disk partition, but the counting question asks about total capacity, not about reservations. Step-by-Step Solution: Identify naming domain: letters A through Z.Compute the total number of distinct letters = 26.Conclude that DOS can recognize 26 different drive letters overall. Verification / Alternative check: In practice, DOS-based systems and Windows shells derived from DOS display drives from A: to Z:, confirming a 26-letter namespace. Even when some letters are unused or reserved, the address space itself remains 26 wide. Why Other Options Are Wrong: 4 and 16: Arbitrary smaller counts that do not match the A–Z convention. 1: Incorrect; clearly more than one drive can exist. None of the above: Incorrect because 26 is correct. Common Pitfalls: Confusing “usable” letters in a particular setup (for example, A:, C:, D:) with the theoretical maximum labeling space. Also, assuming that reserved letters reduce the total count; they reduce availability in practice, not the namespace size. Final Answer: 26

Question 2

SMARTDrive (SMARTDRV.EXE) usage: Which command-line switch displays SMARTDrive status and statistics output on DOS?

Accepted Answer

Introduction / Context: SMARTDrive (SMARTDRV.EXE) is a DOS/Windows 3.x era disk caching utility that accelerates disk access by buffering reads and writes. Knowing its command-line switches is important when tuning legacy systems or analyzing performance and write-caching behavior. Given Data / Assumptions: The question asks for the switch that shows status/statistics. SMARTDRV supports several flags for enabling/disabling write-behind, excluding drives, and printing summaries. We assume a typical DOS environment with SMARTDRV loaded. Concept / Approach: The summary/statistics switch prints the current cache configuration (cache sizes, write-behind state) and counters. This is typically invoked at the command prompt to verify settings after AUTOEXEC/CONFIG configuration changes. Step-by-Step Solution: Recall commonly used switches: /S (status/summary), /X (disable write-behind), /E: (exclude drives), and /O:n (set options).Match “displays status and statistics” with the summary output switch.Select /s as the appropriate switch. Verification / Alternative check: Running SMARTDRV without parameters after loading often displays a brief status; explicitly adding /S prints a fuller summary of cache settings and hits/misses on many versions, which technicians use to confirm effective caching. Why Other Options Are Wrong: /x: Disables write-behind caching; does not show a summary. /e:: Excludes a drive from caching; not a status switch. /o:n: Sets options; not for printing summary. None of the above: Incorrect because /s is correct. Common Pitfalls: Assuming /x shows information because it changes behavior. Also, confusing the informational output shown when SMARTDRV is run with no parameters with the explicit statistics output requested here. Final Answer: /s

Question 3

Hayes AT command set — manual dialing: Which command will manually dial the telephone number 123-4567 using a tone-dial modem?

Accepted Answer

Introduction / Context: Classic dial-up modems use the Hayes AT command set. Understanding basic commands such as dialing is essential when testing, scripting, or troubleshooting dialers and communications software. Given Data / Assumptions: We are using a Hayes-compatible modem. Tone dialing is requested (as opposed to pulse dialing). The number to dial is 123-4567 (hyphen is ignored by the modem). Concept / Approach: The generic dialing command format is ATD followed by a dialing modifier. ATDT specifies tone mode; ATDP specifies pulse mode. The digits of the phone number follow immediately, with optional punctuation ignored. Step-by-Step Solution: Select the correct dial prefix: ATD (dial).Specify tone dialing: T gives ATDT.Append the number: ATDT1234567.Send the command on the terminal to initiate the call. Verification / Alternative check: Most terminal emulators and modem manuals show ATDT for tone dialing and ATDP for pulse. Issuing ATDT followed by a number audibly triggers touch-tone sequences on an analog line. Why Other Options Are Wrong: AT1234567: Missing the D (dial) and tone/pulse specifier. AT1234567DL: Not a recognized form for dialing. ATM 1234567: M controls speaker; the space and syntax are invalid for dialing. None of the above: Incorrect because ATDT1234567 is correct. Common Pitfalls: Forgetting the T (tone) or using ATDP on tone-only lines; including spaces where none are allowed; and mistaking ATZ (reset) or ATH (hang up) for dialing commands. Final Answer: ATDT1234567

Question 4

DOS boot sequence — system files checked at startup: Each time you power on a DOS PC, which core system files are loaded/checked during the bootstrap process?

Accepted Answer

Introduction / Context: Legacy DOS boot relies on a small set of critical system files. Technicians often need to know the minimum files for a bootable disk, especially when repairing corrupted systems or creating startup media. Given Data / Assumptions: DOS expects specific hidden system files in the root of the boot drive. File names vary slightly by DOS version, but the trio IO.SYS, MSDOS.SYS, and COMMAND.COM is canonical in MS-DOS. The question asks which files are checked/loaded at power-on. Concept / Approach: The BIOS loads the boot sector, which then loads the DOS system files. IO.SYS initializes hardware interfaces, MSDOS.SYS provides the DOS kernel services, and COMMAND.COM is the command interpreter. If any are missing or corrupted, boot typically fails or drops to a minimal shell. Step-by-Step Solution: BIOS executes boot sector from selected device.Boot sector loads IO.SYS and then MSDOS.SYS.DOS kernel invokes COMMAND.COM as the shell.System becomes ready for CONFIG.SYS and AUTOEXEC.BAT processing. Verification / Alternative check: Creating a bootable floppy with SYS A: places IO.SYS, MSDOS.SYS, and COMMAND.COM in the root, proving these three are required at startup. Why Other Options Are Wrong: COMMAND.COM, IO.SYS: Incomplete; missing MSDOS.SYS (the kernel). COMMAND.COM, DATE.COM, TIME.COM: DATE/TIME are utilities, not core boot files. CHKDSK.EXE: Diagnostic tool; not a boot prerequisite. None of the above: Incorrect because the correct trio is provided. Common Pitfalls: Assuming CONFIG.SYS or AUTOEXEC.BAT are required for boot; they are processed after the core files load. Also, mixing PC-DOS names and MS-DOS names across versions. Final Answer: COMMAND.COM, IO.SYS, MSDOS.SYS

Question 5

Viewing directory trees with paging: Which DOS command displays the subdirectory structure of the current drive and pauses after each screenful of output?

Accepted Answer

Introduction / Context: On DOS systems, long outputs scroll past the screen quickly. Piping commands through the MORE filter makes them readable page by page. Understanding how to combine commands increases efficiency at the command line. Given Data / Assumptions: TREE prints a graphical view of folders (subdirectories). MORE pauses output after each screenful, waiting for a key. The question asks specifically for showing the tree and pausing after each screen. Concept / Approach: Use a pipeline to send the output of TREE to MORE. This retains TREE’s hierarchical display while benefiting from paging. The syntax is straightforward and works with many commands that produce long output. Step-by-Step Solution: Generate subdirectory listing: TREE.Add pagination: pipe via | to MORE.Final command: TREE | MORE.Press a key to advance each page until output completes. Verification / Alternative check: Running TREE alone demonstrates scrolling. Running TREE | MORE clearly paginates the output, matching the problem’s requirement. Why Other Options Are Wrong: TREE: Shows the tree but does not pause. DELTREE /F: Deletes directories; dangerous and unrelated. DIR | MORE: Paginates file listings, not the hierarchical tree. None of the above: Incorrect because TREE | MORE is valid. Common Pitfalls: Accidentally using DELTREE instead of TREE (which can delete folders). Also, forgetting that MORE paginates any standard output, not only DIR output. Final Answer: TREE | MORE

Question 6

DOS formatting basics: When MS-DOS formats a disk, it automatically creates the top-level directory on the disk. What is this directory called?

Accepted Answer

Introduction / Context: Filesystems in DOS/Windows organize files into a hierarchy that begins at a top-level directory. Knowing the correct terminology helps when describing paths, troubleshooting, and scripting. Given Data / Assumptions: Formatting creates filesystem structures including boot sector, file allocation tables, and the initial directory. The top-level directory has a specific, conventional name. This directory exists at the highest level of the drive's directory tree. Concept / Approach: The top-level directory is universally called the “root” directory. Path representations like C:\ and A:\ refer to the root. All other folders branch from this starting point, forming a tree structure underneath. Step-by-Step Solution: Consider the directory tree analogy: tree starts at a root.DOS path syntax shows a backslash from the drive letter to indicate root (for example, C:\).Therefore, the directory created automatically at format time is the root directory. Verification / Alternative check: DIR \ invoked at a drive letter lists the root contents. Documentation for FORMAT and filesystem structures always mentions the root directory as the top level. Why Other Options Are Wrong: Main, area, border: Not standard filesystem terms in DOS. Empty option: Not applicable. Common Pitfalls: Confusing “root directory” with “home directory” terminology from UNIX-like systems; DOS uses root to refer strictly to the top of the drive tree. Final Answer: root

Question 7

Redirecting printer output in DOS: Which DOS command correctly configures printing so that LPT1 output is redirected to the serial port COM1?

Accepted Answer

Introduction / Context: Legacy applications often send print jobs to parallel ports (LPT1). When only a serial printer is available, DOS can redirect output from LPT1 to COM1 using the MODE command. Correct syntax is vital for successful redirection. Given Data / Assumptions: Goal: redirect LPT1 jobs to COM1. DOS provides the MODE utility for device configuration and redirection. Printer and serial parameters may require additional MODE settings (baud, parity) after redirection. Concept / Approach: Use MODE to bind logical devices. The canonical form is MODE LPTn=COMm. After binding, any program printing to LPT1 actually transmits data through COM1, assuming compatible serial settings. Step-by-Step Solution: Invoke MODE with mapping syntax: MODE LPT1=COM1.Optionally set COM1 parameters: MODE COM1:9600,N,8,1 (as needed).Test by printing a small text file to LPT1 from an application or via COPY filename LPT1. Verification / Alternative check: After redirection, issuing a print test results in activity on the serial port. Documentation for MODE shows the LPT-to-COM mapping syntax exactly as above. Why Other Options Are Wrong: Parallel serial, Direct LPT1=COM1, MODE printer ()-serial (): Not valid DOS syntax. None of the above: Incorrect because MODE LPT1=COM1 is correct. Common Pitfalls: Forgetting to set serial parameters to match the printer, or overlooking that some applications bypass DOS and talk directly to hardware (rare), which can defeat redirection. Final Answer: MODE LPT1=COM1

Question 8

Purpose of the MS-DOS COPY command: What does the COPY command enable you to do?

Accepted Answer

Introduction / Context: File management at the DOS command line relies heavily on COPY. Recognizing the breadth of scenarios where COPY applies helps users move, duplicate, and back up data effectively across devices and directories. Given Data / Assumptions: COPY duplicates files from a source path to a destination path. Source and destination can be on different drives or machines (via mapped drives). Goal scenarios include transfer, backup, and media changes (for example, HDD to floppy). Concept / Approach: COPY accepts wildcard patterns, single files, or combinations (for example, concatenating text files). It works with any accessible drive letter, allowing movement between fixed disks, removable media, and network shares. Step-by-Step Solution: To transfer: COPY C:\DATA\LIST.TXT A:\To back up: COPY C:\CONFIG.SYS C:\BACKUP\To move to floppy: COPY C:\REPORT.DOC A:\Verify results with DIR on the destination path. Verification / Alternative check: After issuing COPY, DOS reports file(s) copied. Listing the destination shows the duplicates, confirming the operation across varied use cases. Why Other Options Are Wrong: Each of A, B, and C describes a valid use case; therefore the correct umbrella choice is “All of the above”. None of the above: Incorrect because COPY performs all listed actions. Common Pitfalls: Overwriting files unintentionally without confirmation; forgetting to include wildcards correctly; confusing COPY with XCOPY (which is better for directory trees). Final Answer: All of the above

Question 9

Formatting floppies quickly: Which command syntax instructs DOS to perform a quick format of drive A:?

Accepted Answer

Introduction / Context: Quick format is a time-saving option that recreates filesystem structures without scanning the entire disk surface. Knowing the precise switch helps avoid lengthy operations and supports rapid media preparation. Given Data / Assumptions: We are formatting the A: floppy drive. We need the “quick” variant of FORMAT. Switch syntax follows standard DOS conventions. Concept / Approach: The FORMAT utility accepts /Q to request a quick format. This rebuilds the file allocation tables and root directory, marking all clusters as available, without low-level surface testing (which a full format performs). Step-by-Step Solution: Identify the utility: FORMAT.Specify the target: A:Add the quick switch: /Q.Final form: FORMAT A: /Q. Verification / Alternative check: Running FORMAT /? shows /Q as the quick format parameter, confirming the correct syntax in multiple DOS versions and Windows command shells that retain DOS compatibility. Why Other Options Are Wrong: /QUICK, /QU, /QF: Not standard FORMAT switches in DOS; they will error or be ignored. None of the above: Incorrect since /Q is valid. Common Pitfalls: Assuming quick format checks for bad sectors (it does not); using it on suspect media may leave undetected errors. For thorough verification, use a full format without /Q. Final Answer: FORMAT A: /Q

Question 10

Protecting files from modification in DOS: Which command makes the file CBT.EXE read-only to prevent subsequent changes?

Accepted Answer

Introduction / Context: DOS file attributes control visibility and mutability. Setting the read-only attribute prevents edits and overwrites by many utilities. Technicians frequently toggle attributes to protect executables and configuration files. Given Data / Assumptions: The file is CBT.EXE in the current directory. We want to prevent changes by setting read-only. DOS provides ATTRIB to manage file attributes (Read-only, Archive, System, Hidden). Concept / Approach: ATTRIB accepts +R to add the read-only attribute and -R to remove it. Once set, typical copy or editor operations will prompt or fail to overwrite unless attributes are cleared or forced by specialized tools. Step-by-Step Solution: Use the attribute utility: ATTRIB.Add the read-only flag: +R.Specify the target file: CBT.EXE.Run: ATTRIB +R CBT.EXE. Verification / Alternative check: Issue ATTRIB CBT.EXE after the command to display current attributes and confirm the R flag is set. Attempting to overwrite will now typically produce an access denied or confirmation prompt. Why Other Options Are Wrong: RENAME +r, COPY +r, MODE +r: These commands do not set attributes and the syntax is invalid in this context. None of the above: Incorrect because ATTRIB +R is correct. Common Pitfalls: Forgetting to remove the attribute when updating the file (use ATTRIB -R CBT.EXE). Also, note that some installers override attributes; verify after updates. Final Answer: ATTRIB +R CBT.EXE

Question 11

DOS directory navigation commands Which two commands in MS-DOS allow you to move between directories (change the current working directory)?

Accepted Answer

Introduction / Context: Navigating the directory tree is a foundational DOS skill for troubleshooting, file management, and software installation. MS-DOS offers commands that change the current working directory so you can access files and run programs located in different folders. Knowing exactly which commands perform directory changes (and which do not) prevents errors and streamlines command-line workflows. Given Data / Assumptions: The environment is MS-DOS or a DOS-compatible command interpreter. We want to change the current working directory. Commonly confused commands like MOVE and DIR are available but serve different purposes. Concept / Approach: Two synonymous commands, CD and CHDIR, are implemented internally by the command interpreter to alter the current directory context. Both accept relative and absolute paths and can show the current directory when used with no arguments. Other commands such as MOVE relocate files, not your working position in the directory tree. Step-by-Step Solution: Use CD foldername to descend into a subdirectory (for example, CD GAMES).Use CD .. to move up one level (parent directory).Use CD \ to jump to the root of the current drive.Use CHDIR exactly as CD; they are synonyms (for example, CHDIR C:\TOOLS).Type CD alone to display the current working directory. Verification / Alternative check: After running CD or CHDIR, issue DIR to list contents, confirming you are now in the intended directory. The prompt often reflects the new path, providing immediate feedback. Why Other Options Are Wrong: a or b alone: Each works, but the question asks for the pair enabling directory changes; the correct concept is that both are valid. c: MOVE moves files or directories to a new location; it does not change your current working directory. e: DIR lists directory contents; it does not navigate. Common Pitfalls: Forgetting quotes when paths include spaces in later shells; confusing moving files (MOVE) with moving the working directory (CD/CHDIR); omitting backslashes in absolute paths. Final Answer: CD and CHDIR

Question 12

DOS startup configuration The PATH command that defines executable search paths is usually placed in which startup file?

Accepted Answer

Introduction / Context: The PATH setting tells DOS where to look for executables beyond the current directory. Correctly placing the PATH command ensures utilities and applications run without needing fully qualified paths, streamlining everyday work and troubleshooting sessions. Given Data / Assumptions: DOS uses CONFIG.SYS for device drivers and system directives. AUTOEXEC.BAT is a batch file executed after DOS loads. We want the standard location for setting the PATH environment variable automatically at each boot. Concept / Approach: Environment variables, including PATH, are typically configured in AUTOEXEC.BAT because it is a batch script executed during startup in user context, ideal for initializing variables, launching TSRs, and setting prompt styles. CONFIG.SYS handles low-level drivers and memory managers; it is not the conventional place for the PATH command. Step-by-Step Solution: Open AUTOEXEC.BAT in a text editor.Add a line such as: PATH C:\DOS;C:\UTIL;C:\TOOLSSave and reboot to apply changes automatically.At the prompt, type PATH to verify the configured directories.Adjust order so the most frequently used tools appear earlier for faster resolution. Verification / Alternative check: Temporarily run PATH from the prompt to test new values. If it works interactively, placing the same line into AUTOEXEC.BAT will persist the setting across reboots. Why Other Options Are Wrong: a: CONFIG.SYS configures drivers (for example, DEVICE=) and memory; it is not the standard location for PATH. b and c: These filenames are nonstandard and not used by DOS for startup. e: Not applicable because AUTOEXEC.BAT is correct. Common Pitfalls: Exceeding environment size limits; forgetting semicolons between paths; setting PATH in the shell only (lost after reboot) rather than in AUTOEXEC.BAT. Final Answer: AUTOEXEC.BAT

Question 13

Display mode switching in MS-DOS Which MODE command switches from a color display to the monochrome (black-and-white) text display?

Accepted Answer

Introduction / Context: Legacy DOS systems supported multiple display adapters and text modes. The MODE command configures console characteristics, including redirecting output to monochrome adapters or switching among text modes. Knowing the exact syntax avoids confusing display settings and illegible output. Given Data / Assumptions: System has a functioning display adapter capable of monochrome mode. We are operating at the DOS command prompt. We need a command that explicitly selects monochrome behavior for text output. Concept / Approach: MODE MONO directs output to the monochrome display. Other MODE options (such as CO40, CO80) select columns and color settings for color adapters but do not switch to monochrome output devices. Syntax must match DOS expectations exactly. Step-by-Step Solution: At the prompt, type MODE MONO and press Enter.Confirm that the system routes text output to the monochrome configuration.Use MODE CO80 to return to an 80-column color text mode if desired.Check readability and contrast after switching modes.Persist the choice by adding to AUTOEXEC.BAT if frequently used. Verification / Alternative check: Run commands that produce text output (for example, DIR) and observe the adapter used. Switching back and forth with MODE commands demonstrates the effect in real time. Why Other Options Are Wrong: a and b: Not valid DOS syntax; MODE does not accept “BLACK” or “B/W”. d: MODE CO40 selects 40-column color text mode, not monochrome. e: Not applicable because MODE MONO is correct. Common Pitfalls: Mis-typing parameters; assuming that MODE commands will work identically across all DOS variants or modern shells—hardware and drivers must support the mode. Final Answer: MODE MONO

Question 14

Upgrading to a newer DOS version Which item is LEAST likely to interfere with a smooth DOS upgrade on a typical PC?

Accepted Answer

Introduction / Context: Before upgrading DOS, technicians consider hardware compatibility, storage layout, and disk utilities that might conflict with setup. Some items commonly complicate upgrades, while others are neutral or even beneficial. Identifying the least problematic element reduces risk and downtime. Given Data / Assumptions: The system currently runs an older DOS version. We may encounter drive compression software (for example, DoubleSpace/DriveSpace). Standard PC hardware (ROM BIOS, video controller) is present. Backup files exist on local or external media. Concept / Approach: Compressed drives can impact boot sequence and file locations, requiring special handling during upgrades. Firmware or BIOS idiosyncrasies can also affect installation. By contrast, having existing backups is a safety net, not an obstacle—backups should assist recovery rather than interfere with the upgrade process. Step-by-Step Solution: Audit the system: identify compression utilities and confirm compatibility.Check vendor notes for ROM BIOS or controller-related issues.Verify sufficient free space and proper CONFIG.SYS/AUTOEXEC.BAT configuration.Ensure backups are complete and stored safely offline before proceeding.Perform the upgrade following vendor guidance. Verification / Alternative check: Simulate the upgrade in a virtual machine with and without compressed drives. You will find compressed setups require additional steps, while the presence of backup files has no negative impact. Why Other Options Are Wrong: a: Some older BIOS versions need updates or special settings for newer DOS features. b: Display adapters occasionally need compatible modes or drivers. c: Drive compression layers can complicate boot and file access during upgrades. e: Not applicable because backups are the least likely to interfere. Common Pitfalls: Upgrading without disabling or preparing drive compression; failing to verify BIOS settings; not creating verified backups before starting. Final Answer: Existing backup files

Question 15

Checking the system clock in DOS If you do not know the current time, which single DOS command displays (and optionally sets) the system time?

Accepted Answer

Introduction / Context: Time and date stamps control file versioning, backup policies, and audit trails. In DOS environments, simple built-in commands let you view and set the system clock without third-party utilities. Choosing the correct command avoids accidental file operations or system changes. Given Data / Assumptions: User is at a DOS prompt. Goal is to display or set the current system time. Standard internal commands are available. Concept / Approach: TIME is an internal command that displays the system time and prompts for a new value if you wish to change it. It works together with DATE for complete timestamp management. Other commands (VER, COPY, FORMAT) serve unrelated purposes and will not show the clock. Step-by-Step Solution: Type TIME and press Enter to display the current time.When prompted, press Enter to keep the same time or type a new time (for example, 14:05:00).Confirm that subsequent file operations show correct timestamps.Use DATE to verify or adjust the date as needed.Consider adding TIME/DATE prompts to batch files for logging. Verification / Alternative check: Create a test file, then run DIR to confirm the timestamp. If you changed the time, the file’s modified time should reflect the new setting, verifying the command’s effect. Why Other Options Are Wrong: a: COPY duplicates files; it does not interact with the clock. b: VER shows DOS version, not time. d: FORMAT prepares media and should not be used casually; unrelated to time. e: Not applicable because TIME is correct. Common Pitfalls: Entering an invalid time format; forgetting to check DATE, which can also impact logs and backups; assuming modern NTP-like synchronization exists by default in DOS. Final Answer: TIME

Question 16

Viewing compression ratios on DoubleSpace/DriveSpace disks Which DIR option displays a column showing the compression ratio for each file (feature introduced in DOS 6.00)?

Accepted Answer

Introduction / Context: DOS 6.x introduced disk compression utilities (DoubleSpace/DriveSpace) and enhanced DIR options to display per-file compression information. This helps users assess savings and identify unusually large or poorly compressed files when managing limited storage. Given Data / Assumptions: The system is DOS 6.00 or later with compression features enabled. We want a DIR switch that adds a compression column. Other DIR switches alter format (wide, bare) or include recursion. Concept / Approach: DIR /C augments the listing to include compression ratios for each file when using DoubleSpace/DriveSpace. This is distinct from listing styles or recursion depth. The switch acts as a reporting aid, not a compression action by itself. Step-by-Step Solution: At the prompt, type DIR /C and press Enter.Review the compression column shown for files on compressed volumes.Use DIR /C /S to include subdirectories if needed.Identify candidates for archiving or deletion based on poor compression or size.Document findings for storage planning. Verification / Alternative check: Run DIR with and without /C on a compressed volume; observe that the additional column appears only when /C is used and the volume supports compression stats. Why Other Options Are Wrong: a: /W uses wide format; no compression column. b: /S includes subdirectories; still no compression column. c: /B shows bare names; it removes extra columns entirely. e: Not applicable because /C is correct for compression ratio display. Common Pitfalls: Expecting /C to compress files; it only reports ratios. On uncompressed volumes, the column may not be meaningful. Final Answer: DIR /C

Question 17

Setting system date and time in DOS Which two DOS commands are used to display or set the system's date and time?

Accepted Answer

Introduction / Context: Accurate system timekeeping is essential for file timestamps, backups, and logs. In MS-DOS, built-in commands allow an operator to display and modify both the date and the time without additional utilities. Knowing the correct pair prevents confusion with unrelated commands such as VER (version). Given Data / Assumptions: User needs to verify or change both date and time. Standard DOS internal commands are available. No third-party clock utilities are required. Concept / Approach: TIME handles the system clock; DATE handles the calendar. Each command, when typed alone, displays the current value and prompts for a new one, allowing the user to press Enter to keep the existing setting or type a replacement using the expected format (regional format may vary). Step-by-Step Solution: Type DATE and press Enter to display the current date; optionally enter a new date.Type TIME and press Enter to display the current time; optionally enter a new time.Confirm changes by creating a test file and checking its timestamp via DIR.Document changes if auditing is required.Repeat as necessary whenever the system battery is replaced or time drifts. Verification / Alternative check: Run VER to confirm OS version differences; note that VER does not display time or date. Timestamps on newly created files will reflect the updated settings, serving as a practical verification. Why Other Options Are Wrong: a: VER reports DOS version; it does not set time. c and d: HOUR and DAY are not valid DOS commands for clock management. e: Not applicable because DATE and TIME are correct. Common Pitfalls: Entering invalid formats; forgetting to adjust both date and time; overlooking timezone implications when moving files across systems. Final Answer: DATE and TIME

Question 18

DOS virus scanning utilities Which DOS utility is used to scan memory and disk for computer viruses and remove infections?

Accepted Answer

Introduction / Context: Before modern antivirus suites, DOS-era systems used Microsoft Anti-Virus tools to detect and remove malware from memory and disks. Selecting the correct tool matters because maintenance utilities like SCANDISK or DEFRAG do not address malicious code and could even spread infections if used carelessly on infected media. Given Data / Assumptions: The system is DOS 6.x with Microsoft Anti-Virus utilities installed. Goal: scan memory and storage, and remove discovered viruses. Utilities named are standard DOS-era tools with distinct purposes. Concept / Approach: MSAV (Microsoft Anti-Virus) performs on-demand scans of memory and disks to detect and clean known viruses. VSAFE is a TSR that provides passive monitoring and alerts but is not a full removal scanner. DEFRAG optimizes file placement; SCANDISK checks and repairs file-system errors. Only MSAV fulfills both scanning and cleaning roles in this list. Step-by-Step Solution: Run MSAV from the DOS prompt.Select memory and full disk scan options.Quarantine or clean infected files as prompted.Reboot and rescan to confirm removal.Update virus definitions if available for the specific MSAV version. Verification / Alternative check: After cleaning, run VSAFE resident protection and repeat the scan. Also, verify system integrity with SCANDISK to ensure file-system structures were not damaged by infection. Why Other Options Are Wrong: b: DEFRAG defragments; it does not detect or remove viruses. c: SCANDISK repairs disk/file-system errors, not malware. d: VSAFE is a resident monitor; it alerts but is not a comprehensive cleaner. e: Not applicable because MSAV is correct. Common Pitfalls: Scanning only the boot drive and forgetting removable media; not rescanning after cleaning; confusing improved performance from DEFRAG with malware removal. Final Answer: MSAV

Question 19

Copying text files to a floppy disk in DOS Which single command copies all files with the .TXT extension from the current drive and directory to drive A?

Accepted Answer

Introduction / Context: Wildcards provide fast, flexible file operations in DOS. When moving groups of files to removable media, the COPY command combined with the asterisk pattern simplifies backups and transfers. Using the correct source–destination order prevents overwriting the wrong location. Given Data / Assumptions: You are in the source directory containing .TXT files. Drive A: is present and writable (for example, a floppy disk). Goal: copy all .TXT files from here to A: in one step. Concept / Approach: The syntax is COPY source destination. A wildcard pattern like *.TXT means “all files ending in .TXT” in the current directory. The destination is specified as a drive or path. The command does not delete originals; it simply duplicates them to the target. Step-by-Step Solution: Insert a formatted disk in drive A:.At the prompt, type COPY *.TXT A: and press Enter.Observe the “n file(s) copied” message indicating success.Run DIR A: to verify the new files are present.Label the floppy and store it securely if used as a backup. Verification / Alternative check: Create a new text file locally and repeat the COPY command; confirm it appears on A:. This validates the pattern and the source–destination order. Why Other Options Are Wrong: a: Reverses source and destination; it attempts to copy from A: to the current directory. c: Copies to C:, not A:. d: Copies multiple files into a single file named ALL.TXT, which is not the goal. e: Not applicable because option b is correct. Common Pitfalls: Forgetting to include the colon after drive letters; insufficient disk space on A:; unintentionally overwriting existing files on the destination without confirmation. Final Answer: COPY *.TXT A:

Question 20

Conserving laptop battery power in DOS 6.x Which DOS 6.x utility enables power management to reduce energy use and extend battery life on portable PCs?

Accepted Answer

Introduction / Context: Mobile DOS systems benefit from software power management that idles the CPU and peripherals when inactive. DOS 6.x included a lightweight utility to enable or tune Advanced Power Management settings, helping prolong battery life without special third-party tools. Given Data / Assumptions: System is running MS-DOS 6.x on portable hardware with APM support. User wants to reduce power draw at idle. Candidate utilities resemble power-related names but may be fictitious or unrelated. Concept / Approach: POWER.EXE is the MS-DOS power management utility. It enables and configures system power-saving policies, such as standby behavior and CPU idling. Correct usage can materially extend run time between charges when paired with compatible BIOS and drivers. Step-by-Step Solution: At the prompt, run POWER to view usage or enable power management.Optionally add POWER to AUTOEXEC.BAT so it loads at startup.Adjust BIOS APM settings to cooperate with DOS power management.Test idle behavior and resume to ensure stability.Monitor battery life improvements across typical workloads. Verification / Alternative check: Compare idle power draw and run time with POWER enabled versus disabled. If the BIOS supports APM, you should observe cooler operation and longer battery life when the utility is active. Why Other Options Are Wrong: a, c, d: These filenames are nonstandard or incorrect for DOS power management. e: Not applicable because POWER.EXE is the correct utility. Common Pitfalls: Expecting aggressive power savings on hardware lacking APM/BIOS support; failing to add the command to startup; confusing POWER with screen savers or CPU throttling tools not present in pure DOS. Final Answer: Power.exe

Disk Operating System (DOS) Questions