Question 1

DOS utilities:  At a DOS prompt, which command displays a summary of memory usage and the amount of memory available?

Accepted Answer

Introduction / Context: Legacy DOS tools are still referenced in certification exams and basic troubleshooting. The MEM command provides a quick overview of conventional, upper, and extended memory usage, including drivers and TSRs, which is invaluable when diagnosing low-memory issues. Given Data / Assumptions: MS-DOS or DOS-compatible command line. Goal: see how much memory is free and where it is consumed. Common related tools include CHKDSK and MEMMAKER. Concept / Approach: MEM outputs totals and breakdowns of free and used memory. Switches like /C list drivers and TSRs with memory blocks, while /P paginates output. CHKDSK primarily checks disk and filesystem structures; MEMMAKER optimizes memory usage but does not directly display a live summary like MEM. Step-by-Step Solution: At the prompt, run MEM or MEM /C for detail.Read free conventional memory and upper memory blocs.Identify large TSRs or drivers and remove or relocate them if needed.Reboot after changes and verify improvements using MEM again. Verification / Alternative check: Compare MEM output before and after removing TSRs to confirm reclaimed memory. Why Other Options Are Wrong: EMM: not a DOS command; refers to Expanded Memory Manager conceptually. CHKDSK: reports drive and file structure statistics, not memory usage summary. MEMMAKER: optimization wizard, not the real-time summary tool. None of the above: incorrect because MEM is correct. Common Pitfalls: Confusing conventional memory limitations with XMS/EMS; forgetting that high memory loading depends on HIMEM/EMM386 drivers and device configurations. Final Answer: MEM

Question 2

PC security fundamentals: If you suspect a computer virus infection, which of the following components is generally not altered or directly infected by typical PC viruses?

Accepted Answer

Introduction / Context: Viruses and malware typically target storage and executable code: boot sectors, master boot records, operating system files, and user programs. Understanding common targets helps you prioritize scans and backups when an infection is suspected. Given Data / Assumptions: Classic PC environment with removable media and bootable disks. Viruses may infect boot sectors, executable files, and spread via floppies. CMOS is a small non-volatile memory that stores system configuration. Concept / Approach: Traditional viruses write to the boot sector or infect program files to gain control during startup or execution. They can also copy themselves to removable media like floppy disks. Direct modification of CMOS configuration values by viruses is uncommon; while some malware can change CMOS settings, this is not a typical or necessary infection vector because CMOS stores settings, not executable code. Step-by-Step Solution: Evaluate common infection vectors: boot sectors, executables, removable media.Recognize that CMOS contains parameters (time, boot order) and not general code.Select CMOS as the component least likely to be infected directly.Proceed with boot-sector and file-system scans and backups. Verification / Alternative check: Antivirus logs typically report infected files and boot records, not CMOS edits. BIOS setup changes might occur due to user error or battery issues rather than viral action. Why Other Options Are Wrong: Boot sector: historically a very common malware target. Program files: classic file-infecting viruses modify executables. Floppy disks: frequently used for propagation in legacy systems. None of the above: incorrect because CMOS is the least likely target. Common Pitfalls: Confusing malware side effects (like altered boot order) with direct CMOS infection; ignoring bootable media scans; neglecting offline backups before cleaning. Final Answer: CMOS

Question 3

Basic display troubleshooting steps:  When determining whether a PC display subsystem is functioning, which diagnostic questions should you ask or check first?

Accepted Answer

Introduction / Context: Systematically narrowing down a “no video” complaint begins with simple, non-invasive checks. Power, basic POST beeps, screen controls, and physical signs of operation can quickly isolate whether the issue is the monitor, the GPU, the cable, or the system itself. Given Data / Assumptions: Desktop or CRT-era monitor is suspected of not displaying an image. We have access to the system unit, the display, and front-panel controls. Initial checks precede swapping parts. Concept / Approach: Always start with fundamentals: verify monitor power and brightness/contrast settings, ensure signal cables are secure, listen for motherboard POST beeps, and look for any on-screen activity or status LEDs. On CRTs, static on the glass indicates high-voltage circuits are active; on LCDs, backlight and power LEDs indicate life. Combining all of these quick checks gives a clearer direction before deeper diagnostics. Step-by-Step Solution: Check brightness/contrast or backlight levels.Listen for POST beeps or chimes indicating successful hardware init.Look for a cursor, OSD messages, or power/standby LEDs.Feel for CRT static or observe LCD backlight glow to confirm the display is energized. Verification / Alternative check: Swap with a known-good cable or monitor. If the system beeps normally and a second monitor works, the original monitor or cable is faulty. If no beeps and no video on either display, suspect the system or GPU. Why Other Options Are Wrong: Individual checks alone can miss the root cause; the best first answer is to do all of them quickly. Common Pitfalls: Overlooking a dimmed backlight, muted brightness, or a loose cable; skipping POST beep observation; assuming the GPU is bad without testing. Final Answer: All of the above

Question 4

Magnetic interference and data media:  Why should floppy disks, hard drives, and magnetic tape (for example, VCR or cassette tapes) be kept away from loudspeakers and other strong magnets?

Accepted Answer

Introduction / Context: Magnetic storage media rely on precisely oriented magnetic domains to encode data. External magnetic fields can disturb or erase these domains, causing data corruption or total data loss. Speakers contain permanent magnets and can create strong localized fields capable of damaging nearby media. Given Data / Assumptions: Devices: floppy disks, magnetic hard drives, and tapes store data magnetically. Speakers and certain motors produce strong magnetic fields. We are distinguishing electromagnetic interference (EMI) from radio-frequency interference (RFI). Concept / Approach: EMI refers to unwanted electromagnetic effects that can disrupt operation or stored states. For magnetic media, static or slowly varying fields can reorient magnetic domains. RFI is a subset of EMI at radio frequencies affecting signal integrity; while RFI can cause noise, the primary risk to magnetic media near a magnet is direct magnetic disturbance—best categorized as EMI. Step-by-Step Solution: Identify the hazard: strong permanent magnet adjacent to magnetic media.Recognize the mechanism: external field alters the media’s magnetic domains.Classify the interference: electromagnetic interference (EMI) rather than mere RF noise.Mitigate: maintain distance, use shielding or non-magnetic storage locations. Verification / Alternative check: Manufacturers warn against storing magnetic media near magnets. Testing with degaussing coils demonstrates how magnetic fields erase tapes and floppies. Why Other Options Are Wrong: RFI: focuses on radio-frequency emissions, not the static magnetic fields that erase media. EXE / FYI / IOU: unrelated acronyms, included as distractors. Common Pitfalls: Confusing magnetic erasure with RF noise; assuming modern hard drives are immune (strong fields can still damage or confuse servo tracking if sufficiently close). Final Answer: EMI

Question 5

Electrical units refresher:  In SI units, electric current is measured in which unit?

Accepted Answer

Introduction / Context: A quick review of SI electrical units helps avoid confusion during troubleshooting and measurement. Technicians must correctly select the meter function and range for current, voltage, resistance, and capacitance to obtain valid readings and prevent damage. Given Data / Assumptions: We are identifying the SI unit of electric current. Basic electrical quantities: voltage (V), current (I), resistance (R), capacitance (C). Common units: volt, ampere, ohm, farad. Concept / Approach: The ampere (amp) is the SI base unit for electric current. Voltage is measured in volts, resistance in ohms, and capacitance in farads. Correct unit recognition ensures proper meter usage: current requires placing the meter in series with the circuit and moving the probe to the current jack with an appropriate fuse rating. Step-by-Step Solution: Recall definitions: current = rate of charge flow in coulombs per second.SI base unit for current is the ampere (A).Therefore select “amps” as the correct unit.Use appropriate DMM settings and series connection when measuring. Verification / Alternative check: Any physics or electronics reference lists ampere as the unit of current; meter front panels label current ranges as A or mA. Why Other Options Are Wrong: Volts: unit of electric potential difference. Ohms: unit of resistance. Farads: unit of capacitance. Diodes: a component, not a unit. Common Pitfalls: Placing a meter across a source on the amps range (short-circuit risk); forgetting to move the probe back from the current jack after measurement. Final Answer: amps

Question 6

In which mode can two or more applications be stored in memory at the same time?

Accepted Answer

Protected Mode

Question 7

RTS stands for:

Accepted Answer

request to send

Question 8

When connecting a ribbon cable to a connector, how do you know which direction to plug it in?

Accepted Answer

The colored line in the cable goes to pin #1

Question 9

In which phase of the laser printing process is a positive charge placed on the paper to pull the toner from the print drum?

Accepted Answer

Transferring

Question 10

To install a second IDE drive into a computer, you must:

Accepted Answer

Set the master-slave jumper to slave on the second drive

Question 11

How many pins on a VGA?

Accepted Answer

15.

Question 12

After trying to unload a TSR, you get an error message saying that other TSRs were loaded after the one you tried to remove. Which of the following commands could you use to see the current load order?

Accepted Answer

MEM /C (A SYS:

Question 13

Legacy NIC configuration (non–Plug and Play, no jumpers): When installing a network interface card that does not support Plug and Play and has no physical jumpers, which method is used to set the required IRQ (interrupt request) for the adapter?

Accepted Answer

Introduction / Context: Older network interface cards (NICs) sometimes lacked both Plug and Play (PnP) capability and physical jumper blocks. Technicians had to assign hardware resources such as IRQ, I/O base address, and sometimes DMA using vendor-provided tools. Knowing how these legacy cards are configured is vital when maintaining or restoring vintage systems. Given Data / Assumptions: The NIC has no jumpers or DIP switches. The NIC is not Plug and Play, so resources are not auto-assigned by BIOS/OS. Typical resources include IRQ, I/O port, and possibly DMA. Concept / Approach: Non-PnP, jumperless expansion cards commonly store settings in on-card nonvolatile memory (EEPROM). Vendors supply a DOS-based or utility-based configuration software that writes the chosen IRQ/I-O/DMA values to the card. BIOS setup (CMOS) does not directly set a particular card’s IRQ; at best it can reserve resources. The operating system can cooperate with settings, but it cannot program the hardware on such cards without the vendor utility. Step-by-Step Solution: Identify that the card is non-PnP and jumperless, so a software utility is necessary.Boot to a suitable environment (often DOS) and run the vendor’s configuration program.Select an available IRQ that does not conflict with other devices, then save to the card’s EEPROM.Verify in the OS that the selected IRQ is free and the driver matches the programmed settings. Verification / Alternative check: Use system resource viewers or diagnostics to confirm the NIC responds at the configured I/O port and IRQ. Successful packet transmission or link activity confirms correct configuration. Why Other Options Are Wrong: DMA: Some NICs use DMA, but DMA is not how you set the IRQ. CMOS: BIOS can reserve resources but does not program the NIC’s EEPROM. the OS: The OS relies on the card being configured; it typically cannot program non-PnP jumperless cards. None of the above: Incorrect because configuration software is the standard method. Common Pitfalls: Forgetting to document chosen IRQ/I-O; resource conflicts with sound cards or COM ports; mixing driver versions that assume different settings. Final Answer: configuration software

Question 14

Laser printer fuser maintenance: To prevent toner from sticking to a laser printer’s heated rollers, which substance is properly used as a release agent on the fuser mechanism?

Accepted Answer

Introduction / Context: The fuser assembly in a laser printer bonds toner to paper using heat and pressure. Without a suitable release agent, molten toner can adhere to the hot roller surface, causing smearing, ghosting, and paper wrap. Understanding the correct maintenance material protects print quality and the fuser’s lifespan. Given Data / Assumptions: A laser printer uses a hot fuser roller and pressure roller to fix toner. We need a material that prevents toner offset and roller sticking. Safety and compatibility with fuser materials (silicone rubber, Teflon sleeves) are required. Concept / Approach: Manufacturers specify a high-temperature, non-reactive silicone oil or equivalent release agent for the fuser area. This oil creates a thin film that reduces adhesion between toner and the roller surface. Alcohol and ammonia are cleaning agents; they evaporate quickly, can damage rollers, and do not provide the necessary release film. Non-technical substances (e.g., alcoholic beverages) are inappropriate and unsafe. Step-by-Step Solution: Identify the function: reduce toner adhesion at high temperature.Select a release agent stable at fuser temperatures (silicone oil).Apply according to the service manual (light, uniform application or oil web mechanism).Test print to confirm elimination of offset and sticking. Verification / Alternative check: After service, continuous multi-page prints should show clean areas and no repeating defects matching roller circumference. If sticking persists, inspect the fuser sleeve or pressure roller and confirm correct oil grade. Why Other Options Are Wrong: Alcohol: Degreases and dries; not a release film and may damage coatings. Ammonia: Corrosive/cleaner; unsuitable for fuser surfaces. Beer or Jack Daniels: Not technical lubricants; unsafe and ineffective. None of the above: Incorrect because specified oils are used in many fuser designs. Common Pitfalls: Over-oiling causing smears; using the wrong viscosity; touching hot parts and ignoring safety; forgetting that many modern printers use oil-less fusers—follow the specific model’s service guide. Final Answer: Oil

Question 15

Laser printing process (conditioning step): During the conditioning phase of a laser printer, a uniform charge of what magnitude and polarity is placed on the photosensitive drum?

Accepted Answer

Introduction / Context: Laser printers form images using electro-photography. A key step is conditioning (primary charging), where the drum receives a uniform electrostatic charge to prepare it for exposure by the laser. Knowing the typical charge level and polarity helps diagnose print defects such as backgrounding or light prints. Given Data / Assumptions: The printer uses a standard organic photoconductor (OPC) drum. A primary charge is applied by a corona wire or primary charge roller (PCR). We seek the typical magnitude and polarity used in many engines. Concept / Approach: Most laser printers bias the drum to a negative potential before laser exposure. Common targets are around -600 V (model-dependent). This uniform negative charge is selectively discharged by the laser to form the latent image. Positive values such as +600 V are atypical for common office printers, and low values like +12 V are far below operational requirements. Step-by-Step Solution: Recall: Conditioning sets a uniform charge on the drum.Identify the usual level as several hundred volts negative.From the options, select -600 volts as the representative value. Verification / Alternative check: Service manuals specify PCR bias values; measuring with high-voltage probes or reading diagnostic logs confirms the operating range. Print-quality symptoms often correlate with improper drum bias. Why Other Options Are Wrong: +1000 volt / +600 volts: Incorrect polarity for typical systems. -1000 volts: Possible in some designs, but -600 V is the commonly cited standard value in many office printers. +12 volts: Far too low for drum conditioning. Common Pitfalls: Confusing developer bias, transfer bias, and drum bias; overlooking that exact values vary by model; assuming corona-wire systems when a PCR is used. Final Answer: -600 volts

Question 16

PC startup configuration: When you change the system start-up boot sequence (for example, USB first, then SSD), which system area are you modifying?

Accepted Answer

Introduction / Context: Choosing the order in which a PC searches devices for a bootable OS is fundamental to troubleshooting and deployment. This configuration resides in firmware settings rather than operating system startup files, so technicians must know where to make changes. Given Data / Assumptions: We want to change device priority (e.g., USB, optical drive, NVMe, SATA). Modern systems use UEFI/BIOS menus stored in nonvolatile memory (commonly termed CMOS settings). Legacy DOS files (CONFIG.SYS, AUTOEXEC.BAT) run after boot begins. Concept / Approach: The boot order is set in firmware configuration (BIOS or UEFI). The settings are stored in nonvolatile memory historically called CMOS. CONFIG.SYS, AUTOEXEC.BAT, and COMMAND.COM are operating-system components loaded after a boot device has already been selected; they do not decide which device is attempted first. Step-by-Step Solution: Enter firmware setup (e.g., by pressing Del/F2/Esc depending on vendor).Navigate to Boot or Startup options.Reorder devices and save (settings persist in CMOS).Reboot to verify the new boot sequence is honored. Verification / Alternative check: Use a one-time boot menu to confirm device selection; if the firmware shows the new device order and the system boots accordingly, the change is in effect. Why Other Options Are Wrong: CONFIG.SYS / AUTOEXEC.BAT: Control drivers and environment under DOS after boot begins. COMMAND.COM: DOS command interpreter, not the boot selector. None of the above: Incorrect because BIOS/CMOS is the correct area. Common Pitfalls: Confusing firmware boot order with OS boot loader order; Secure Boot or UEFI-CSM settings interfering; forgetting to save changes before exit. Final Answer: BIOS/CMOS

Question 17

Legacy drive setup workflow: After performing a low-level format on a hard drive, what is the next step to prepare the disk for use by the operating system?

Accepted Answer

Introduction / Context: Classic drive initialization involved distinct stages: low-level formatting (physical), partitioning (logical layout), and high-level formatting (file system). Understanding the correct order avoids wasted effort and ensures the OS recognizes the disk properly. Given Data / Assumptions: A low-level format has just been completed (rare on modern drives, common historically). The OS expects a partition table defining at least one usable partition. High-level format creates the file system inside a selected partition. Concept / Approach: After a low-level format defines physical tracks/sectors, you must create partitions using a tool such as FDISK (or modern equivalents). Only after partitioning can you run a high-level format (e.g., FORMAT C:) to put a file system in place. Installing the OS comes last, after a formatted, mounted partition exists. Step-by-Step Solution: Run partitioning utility to create primary/extended/logical partitions.Mark the active partition if required for booting.Perform high-level format on the new partition(s) to create the file system.Proceed with OS installation onto the formatted target. Verification / Alternative check: Disk management tools should show the created partition table; drive letters mount; a directory structure appears after high-level format, confirming readiness for OS installation. Why Other Options Are Wrong: Format DOS partition: Premature if you have not created the partition yet. Install operating system: Requires an existing, formatted partition. Configure DMA/interrupt: Not a typical step in standard disk prep. None of the above: Incorrect because partitioning is the proper next step. Common Pitfalls: Skipping the active flag on the primary partition; formatting the wrong drive; mis-sizing partitions for the chosen file system’s limits. Final Answer: Partition hard disk

Question 18

ESD safety practice: For a conductive (ESD-safe) workbench, what is the best and correct ground reference to connect to for safe static discharge control?

Accepted Answer

Introduction / Context: Electrostatic discharge (ESD) control requires all conductive surfaces, wrist straps, and tools to share a common reference to earth ground. A properly grounded ESD workbench minimizes potential differences that can damage sensitive components. Given Data / Assumptions: The facility provides three-prong outlets with a verified safety ground. Bench mats and wrist straps include ground leads with resistors (typically 1 megaohm). Goal is a reliable, consistent earth reference for dissipating static safely. Concept / Approach: The recommended ground for ESD benches is the verified earth/safety ground provided by the building’s AC outlet ground pin or a dedicated earth ground point. Connecting to another device’s chassis can create ground loops or float if that device is not properly grounded. Vague or misspelled options such as “Ground to bend” are not recognized standards. The AC outlet ground (tested and verified) is the correct, code-compliant reference. Step-by-Step Solution: Verify the outlet ground with an outlet tester.Connect the bench ground cord to the outlet’s ground (often via a banana-to-ground adapter) through a 1 megaohm safety resistor.Connect wrist straps to the bench common point ground.Confirm low-resistance continuity to earth ground while maintaining the series safety resistor. Verification / Alternative check: Use a continuity/ground monitor or ESD workstation tester to confirm proper grounding and resistance. Observe reduced ESD incidents and stable handling for ICs. Why Other Options Are Wrong: Ground to bend: Not a recognized or meaningful standard connection. To another device: Risky; the other device may be floating or poorly grounded. Chassis ground: Only acceptable if the chassis is verified earth-grounded; the safest and intended reference is the AC outlet earth ground. None of the above: Incorrect because the AC outlet ground is correct. Common Pitfalls: Using painted screws with poor conductivity; bypassing the series resistor; failing to routinely check ground integrity. Final Answer: AC outlet

Question 19

DOS device drivers: Match the driver HIMEM.SYS to its correct function in classic DOS/Windows environments.

Accepted Answer

Introduction / Context: Legacy DOS systems relied on CONFIG.SYS drivers to extend memory functionality. Two commonly confused components are HIMEM.SYS (extended memory) and EMM386.EXE (expanded memory emulation). Correct identification helps when tuning memory for older software. Given Data / Assumptions: System is MS-DOS or early Windows (real/standard mode) era. HIMEM.SYS is loaded via CONFIG.SYS. We differentiate extended vs. expanded memory services. Concept / Approach: HIMEM.SYS is the XMS (Extended Memory Specification) manager. It enables access to memory above 1 MB (beyond the 1 MB real-mode barrier) using the High Memory Area (HMA) and extended memory blocks. EMM386.EXE, by contrast, uses the 80386’s paging to emulate EMS (Expanded Memory Specification) from extended memory. ANSI.SYS handles terminal features; code page switching is managed by DISPLAY.SYS/KEYB and related utilities. Step-by-Step Solution: Identify HIMEM.SYS as the XMS driver.Recall that XMS = extended memory management, not EMS.Select the option describing “manages the use of extended memory.” Verification / Alternative check: Examining CONFIG.SYS lines and boot messages shows “HIMEM is testing extended memory.” DOS utilities like MEM display XMS availability when HIMEM.SYS is active. Why Other Options Are Wrong: ANSI terminal emulation: Provided by ANSI.SYS. Uses expanded memory on a 80386: That is EMM386.EXE, not HIMEM.SYS. Code page switching: Managed by internationalization drivers, not HIMEM.SYS. None of the above: Incorrect; the extended memory management description is correct. Common Pitfalls: Confusing XMS with EMS; forgetting load order (HIMEM.SYS before EMM386.EXE); overlooking that some programs require EMS specifically. Final Answer: Manages the use of extended memory

Question 20

DOS memory query: In classic DOS, which command do you type to display how much memory is available and how it is allocated (conventional, UMB, XMS/EMS)?

Accepted Answer

Introduction / Context: Before modern GUIs, memory layout and optimization were performed at the command line. DOS provided built-in tools to report memory usage and help troubleshoot drivers and TSRs that consumed conventional memory. Given Data / Assumptions: The user needs a quick readout of free/used memory categories. System may have XMS/EMS providers like HIMEM.SYS and EMM386.EXE. We want the standard DOS command, not third-party utilities. Concept / Approach: The MEM command displays memory status, including conventional memory, upper memory blocks (UMBs), and the presence of XMS/EMS. CHKDSK focuses on disk and file system checking. MEMMAKER is a separate utility that attempts to optimize memory use, not simply display it. “EMM” is not a standard DOS command by itself. Step-by-Step Solution: Open the DOS prompt.Type MEM (optionally with switches like /C or /P for details).Read the report showing free and used memory areas. Verification / Alternative check: Compare MEM output before and after loading drivers or TSRs to see changes. Use MEM /C to list modules occupying conventional memory. Why Other Options Are Wrong: EMM: Not a standard reporting command. CHKDSK: Disk integrity tool, not a memory usage reporter. MEMMAKER: Optimizes memory layout; does not just display it. None of the above: Incorrect because MEM is correct. Common Pitfalls: Misinterpreting EMS vs. XMS; forgetting that MEM’s detail switches provide deeper insights; assuming MEM exists in all non-DOS environments. Final Answer: MEM

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