Computer Freezing When Resuming from Sleep
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ZD421 and ZD621 Users Guide (En)
ZD421 and ZD621 Series Link-OS® Printers User Guide P1123730-01EN ZEBRA and the stylized Zebra head are trademarks of Zebra Technologies Corporation, registered in many jurisdictions worldwide. All other trademarks are the property of their respective owners. © 2021 Zebra Technologies Corporation and/or its affiliates. All rights reserved. Information in this document is subject to change without notice. The software described in this document is furnished under a license agreement or nondisclosure agreement. The software may be used or copied only in accordance with the terms of those agreements. For further information regarding legal and proprietary statements, please go to: SOFTWARE: zebra.com/linkoslegal COPYRIGHTS: zebra.com/copyright WARRANTY: zebra.com/warranty END USER LICENSE AGREEMENT: zebra.com/eula Terms of Use Proprietary Statement This manual contains proprietary information of Zebra Technologies Corporation and its subsidiaries (“Zebra Technologies”). It is intended solely for the information and use of parties operating and maintaining the equipment described herein. Such proprietary information may not be used, reproduced, or disclosed to any other parties for any other purpose without the express, written permission of Zebra Technologies. Product Improvements Continuous improvement of products is a policy of Zebra Technologies. All specifications and designs are subject to change without notice. Liability Disclaimer Zebra Technologies takes steps to ensure that its published Engineering specifications and manuals are -
Hang Analysis: Fighting Responsiveness Bugs
Hang Analysis: Fighting Responsiveness Bugs Xi Wang† Zhenyu Guo‡ Xuezheng Liu‡ Zhilei Xu† Haoxiang Lin‡ Xiaoge Wang† Zheng Zhang‡ †Tsinghua University ‡Microsoft Research Asia Abstract return to life. However, during the long wait, the user can neither Soft hang is an action that was expected to respond instantly but in- cancel the operation nor close the application. The user may have stead drives an application into a coma. While the application usu- to kill the application or even reboot the computer. ally responds eventually, users cannot issue other requests while The problem of “not responding” is widespread. In our expe- waiting. Such hang problems are widespread in productivity tools rience, hang has occurred in everyday productivity tools, such as such as desktop applications; similar issues arise in server programs office suites, web browsers and source control clients. The actions as well. Hang problems arise because the software contains block- that trigger the hang issues are often the ones that users expect to re- ing or time-consuming operations in graphical user interface (GUI) turn instantly, such as opening a file or connecting to a printer. As and other time-critical call paths that should not. shown in Figure 1(a), TortoiseSVN repository browser becomes unresponsive when a user clicks to expand a directory node of a This paper proposes HANGWIZ to find hang bugs in source code, which are difficult to eliminate before release by testing, remote source repository. The causes of “not responding” bugs may be complicated. An as they often depend on a user’s environment. HANGWIZ finds hang bugs by finding hang points: an invocation that is expected erroneous program that becomes unresponsive may contain dead- to complete quickly, such as a GUI action, but calls a blocking locks (Engler and Ashcraft 2003; Williams et al. -
What Is an Operating System III 2.1 Compnents II an Operating System
Page 1 of 6 What is an Operating System III 2.1 Compnents II An operating system (OS) is software that manages computer hardware and software resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function. Memory management Among other things, a multiprogramming operating system kernel must be responsible for managing all system memory which is currently in use by programs. This ensures that a program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. Cooperative memory management, used by many early operating systems, assumes that all programs make voluntary use of the kernel's memory manager, and do not exceed their allocated memory. This system of memory management is almost never seen any more, since programs often contain bugs which can cause them to exceed their allocated memory. If a program fails, it may cause memory used by one or more other programs to be affected or overwritten. Malicious programs or viruses may purposefully alter another program's memory, or may affect the operation of the operating system itself. With cooperative memory management, it takes only one misbehaved program to crash the system. Memory protection enables the kernel to limit a process' access to the computer's memory. Various methods of memory protection exist, including memory segmentation and paging. All methods require some level of hardware support (such as the 80286 MMU), which doesn't exist in all computers. -
User's Manual 2
USER'S MANUAL 2 - © 2018. All Rights Reserved. Nitro 5 Covers: AN515-42 / AN515-52 This revision: March 2018 Important This manual contains proprietary information that is protected by copyright laws. The information contained in this manual is subject to change without notice. Some features described in this manual may not be supported depending on the Operating System version. Images provided herein are for reference only and may contain information or features that do not apply to your computer. Acer Group shall not be liable for technical or editorial errors or omissions contained in this manual. Register your Acer product 1. Ensure you are connected to the Internet. 2. Open the Acer Product Registration app. 3. Install any required updates. 4. Sign up for an Acer ID or sign in if you already have an Acer ID, it will automatically register your product. After we receive your product registration, you will be sent a confirmation email with important data. Model number: _________________________________ Serial number: _________________________________ Date of purchase: ______________________________ Place of purchase: ______________________________ Table of contents - 3 TABLE OF CONTENTS First things first 6 BIOS utility 39 Your guides ............................................. 6 Boot sequence....................................... 39 Basic care and tips for using your Setting passwords ................................. 39 computer.................................................. 6 Power management 40 Turning your computer off.......................... -
Getting Started with Symantec Endpoint Encryption for Bitlocker
Getting Started with Symantec Endpoint Encryption for BitLocker Version 11.3.0 Getting Started with Symantec Endpoint Encryption for BitLocker Legal Notice Copyright © 2019 Symantec Corporation. All rights reserved. Symantec, the Symantec Logo, the Checkmark Logo and are trademarks or registered trademarks of Symantec Corporation or its affiliates in the U.S. and other countries. Other names may be trademarks of their respective owners. This Symantec product may contain third party software for which Symantec is required to provide attribution to the third party (“Third Party Programs”). Some of the Third Party Programs are available under open source or free software licenses. The License Agreement accompanying the Software does not alter any rights or obligations you may have under those open source or free software licenses. Please see the Third Party Legal Notice Appendix to this Documentation or TPIP ReadMe File accompanying this Symantec product for more information on the Third Party Programs. The product described in this document is distributed under licenses restricting its use, copying, distribution, and decompilation/reverse engineering. No part of this document may be reproduced in any form by any means without prior written authorization of Symantec Corporation and its licensors, if any. THE DOCUMENTATION IS PROVIDED "AS IS" AND ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE DISCLAIMED, EXCEPT TO THE EXTENT THAT SUCH DISCLAIMERS ARE HELD TO BE LEGALLY INVALID. SYMANTEC CORPORATION SHALL NOT BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, PERFORMANCE, OR USE OF THIS DOCUMENTATION. -
Mac OS X: an Introduction for Support Providers
Mac OS X: An Introduction for Support Providers Course Information Purpose of Course Mac OS X is the next-generation Macintosh operating system, utilizing a highly robust UNIX core with a brand new simplified user experience. It is the first successful attempt to provide a fully-functional graphical user experience in such an implementation without requiring the user to know or understand UNIX. This course is designed to provide a theoretical foundation for support providers seeking to provide user support for Mac OS X. It assumes the student has performed this role for Mac OS 9, and seeks to ground the student in Mac OS X using Mac OS 9 terms and concepts. Author: Robert Dorsett, manager, AppleCare Product Training & Readiness. Module Length: 2 hours Audience: Phone support, Apple Solutions Experts, Service Providers. Prerequisites: Experience supporting Mac OS 9 Course map: Operating Systems 101 Mac OS 9 and Cooperative Multitasking Mac OS X: Pre-emptive Multitasking and Protected Memory. Mac OS X: Symmetric Multiprocessing Components of Mac OS X The Layered Approach Darwin Core Services Graphics Services Application Environments Aqua Useful Mac OS X Jargon Bundles Frameworks Umbrella Frameworks Mac OS X Installation Initialization Options Installation Options Version 1.0 Copyright © 2001 by Apple Computer, Inc. All Rights Reserved. 1 Startup Keys Mac OS X Setup Assistant Mac OS 9 and Classic Standard Directory Names Quick Answers: Where do my __________ go? More Directory Names A Word on Paths Security UNIX and security Multiple user implementation Root Old Stuff in New Terms INITs in Mac OS X Fonts FKEYs Printing from Mac OS X Disk First Aid and Drive Setup Startup Items Mac OS 9 Control Panels and Functionality mapped to Mac OS X New Stuff to Check Out Review Questions Review Answers Further Reading Change history: 3/19/01: Removed comment about UFS volumes not being selectable by Startup Disk. -
Why Can't I Wake My Jetdrive 850 up from Hibernation Mode? Why Can't I
Why can't I wake my JetDrive 850 up from Hibernation Mode? If you encounter this problem while the JetDrive 850 is running on battery power, please note that this issue will happen with all NVMe SSDs, including Apple's native NVMe SSD. Our current assumption is that the NVMe driver of the Mac OS is causing it. Please run Terminal on your Mac and enter "sudo pmset -a hibernatemode 3" to reset the mode to its default value: 3. You can also check if the hibernatemode has been successfully altered by entering the command "pmset -g". Why can't I boot from my JetDrive SSD after system migration? If, after installation, your system won't recognize the JetDrive SSD as the default boot drive, and shows you an icon same as the one in the pic below, it could be because the MacOS has upgraded its security level for drives. This is more likely to occur in the 10.14 (Mojave) version. How to solve this: 1. If you have an enclosure for the JetDrive SSD, please place Apple's native SSD in it, and connect the enclosure to your Mac. If you don't have an enclosure, please use an external HDD or SSD with the MacOS installed. 2. Start your Mac, and press the "Option" key. 3. Click on any drive to enter MacOS. 4. Go to System Preferences. Go to "Startup Disk". 5. Select the installed JetDrive SSD as the default boot disk. How to clean install MacOS on the JerDrive 855/850 It is entirely normal to encounter problems attempting to clean install OS to your JetDrive 855/850, as the internet recovery will reinstall to your JetDrive the original operating system that came the same year with the Mac, and since the JetDrive 855/850 only works with High Sierra or later versions (10.13 or later), a clean install of an earlier MacOS is out of the question. -
Green Computing Tips.Pmd
Green Computing Guide For further assistance, additional green computing tips, or more copies of this brouchure, contact: IUE Teaching & Learning Center (765) 973-8561 [email protected] www.iue.edu/tlc Reduce Your Impact on the Acknowledgement Much of the text for this document was Environment adapted from the “University of Buffalo Green Computing Guide” written by Walter Simpson, University of Buffalo Energy Officer. in Two Simple Steps! To manually put the computer and monitor to FAQS How to Reduce Energy sleep: 1. Click on the Apple (OSX) Won’t turning equipment on and off In 2 Simple Steps or go to “Special” on the menu bar at top of your shorten its life? screen (OS9). 2. Select “Sleep.” No. You are far more likely to replace your equipment due to obsolescence! Heat and 1 RIGHT NOW: Waking Up from Sleep Mode time are the primary wear factors. Hard drives Just hit a key to quickly wake up your system. are designed to handle many thousands of on/ Enable Your Power Management Feature off cycles. Most computers and monitors can be TIP: Do you have a flat panel display? Turning programmed to automatically power down to a 2 ONGOING: it off when not in use not only saves energy, low power state (also called “sleep” or Turn It Off Whenever Possible but will conserve the backlight and extend the “standby”) when they are not being used. The life of your monitor. EPA has estimated that enabling sleep mode • When not in use for an extended period of time, reduces a computer’s energy use by 60 to 70 turn off your computer and/or peripherals I thought my computer used about the same percent! (monitor, printer, etc.) wattage as a light bulb. -
Recipe for Mobile Data Security: TPM, Bitlocker, Windows Vista and Active Directory
Recipe for Mobile Data Security: TPM, Bitlocker, Windows Vista and Active Directory Tom Olzak October 2007 If your business is like mine, laptops regularly disappear. Until recently, centrally managed mobile storage encryption solutions for Windows environments were either too costly, required users to carry a key-resident device, or relied on keys residing on local disk. Sometimes the best solution under these circumstances was the presence of administrative controls (i.e. policies) prohibiting users from storing sensitive information on local laptop drives. With the proliferation of TPM 1.2 across most laptop platforms and the release of Microsoft Windows Vista, most roadblocks to laptop data encryption have been removed. In this paper, I explore the challenges facing security managers responsible for laptop data security, TPM technology, and how the features of a TPM can integrate with Microsoft’s Bitlocker and Active Directory technologies to provide for more secure data on the road. The Challenges Vulnerable Laptop Data When a mobile user’s laptop is stolen, a variety of data might be potentially exposed. The following is a short list of some of the most common types of sensitive information that might be found on a laptop drive: ¾ ePHI – Electronic Protected Health Information, protected under the HIPAA, is any information that can be used to uniquely identify a health care recipient. ¾ PII – Essentially, Personally Identifiable Information is any data that can be used to steal a person’s identity. Most states have passed laws requiring businesses to take steps to protect this information as well as to notify and assist victims if this information is compromised. -
Bitleaker: 0 1 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 0 1 0 1 0 0 1 Subverting Bitlocker with One Vulnerability1 1 1
1 1 0 1 0 1 1 0 BitLeaker: 0 1 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 0 1 0 1 0 0 1 Subverting BitLocker with One Vulnerability1 1 1 Seunghun Han, Jun-Hyeok Park (hanseunghun || parkparkqw)@nsr.re.kr Wook Shin, Junghwan Kang, Byungjoon Kim (wshin || ultract || bjkim)@nsr.re.kr Who Are We? - Senior security researcher at the Affiliated Institute of ETRI - Review board member of Black Hat Asia and KimchiCon - Speaker at USENIX Security, Black Hat Asia, HITBSecConf, BlueHat Shanghai, KimchiCon, BeVX, TyphoonCon and BECS - Author of “64-bit multi-core OS principles and structure, Vol.1&2” - a.k.a kkamagui, @kkamagui1 - Senior security researcher at the Affiliated Institute of ETRI - Speaker at Black Hat Asia 2018 ~ 2019 - Embedded system engineer - Interested in firmware security and IoT security - a.k.a davepark, @davepark312 Previous Works Goal of This Presentation - We present an attack vector, S3 Sleep, to subvert the Trusted Platform Modules (TPMs) - S3 sleeping state cuts off the power of CPU and peripheral devices - We found CVE-2018-6622, and it affects a discrete TPM (dTPM) and a firmware TPM (fTPM) - We introduce a new tool, BitLeaker - BitLeaker extracts the Volume Master Key (VMK) of BitLocker from TPMs - BitLeaker can mount a BitLocker-locked partition with the VMK DISCLAIMER - We do not explain BitLocker’s encryption algorithm - We focus on the protection mechanism for the VMK - Especially, the mechanism only with a TPM! - It is a default option of BitLocker - We do not consider combinations of a TPM and other options (PIN or USB startup -
Recovering from Operating System Crashes
Recovering from Operating System Crashes Francis David Daniel Chen Department of Computer Science Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign University of Illinois at Urbana-Champaign Urbana, USA Urbana, USA Email: [email protected] Email: [email protected] Abstract— When an operating system crashes and hangs, it timers and processor support techniques [12] are required to leaves the machine in an unusable state. All currently running detect such crashes. program state and data is lost. The usual solution is to reboot the It is accepted behavior that when an operating system machine and restart user programs. However, it is possible that after a crash, user program state and most operating system state crashes, all currently running user programs and data in is still in memory and hopefully, not corrupted. In this project, volatile memory is lost and unrecoverable because the proces- we use a watchdog timer to reset the processor on an operating sor halts and the system needs to be rebooted. This is inspite system crash. We have modified the Linux kernel and added of the fact that all of this information is available in volatile a recovery routine that is called instead of the normal boot up memory as long as there is no power failure. This paper function when the processor is reset by a watchdog. This resumes execution of user processes after killing the process that was explores the possibility of recovering the operating system executing when the watchdog fired. We have implemented this using the contents of memory in order to resume execution on the ARM architecture and we use a periodic watchdog kick of user programs without any data loss. -
Policy on Computer Power Management
Policy on Computer Power Management Purpose The Stephen M. Ross School of Business at the University of Michigan (“Ross”) has established computer power settings to achieve energy cost savings across the enterprise for all managed desktop and laptop computers. Power management is a feature of computers, monitors, printers and copiers that turns off the power or switches the system to a low-power state when inactive in order to save energy. Power management becomes even more important across an enterprise such as Ross due to the significant amount of energy being used the costs associated with that energy use. More Energy Less Energy Always On Sleep/Standby Desktop Laptop Faster Processor Slower Processor Older Processor Newer Processor Windows PC Apple Mac Heavy Use (Stats, Gaming) Light Use (Microsoft Office, Email) Online Offline Data gathering and research shows that, on average, Ross can save 200 kilowatt-hours (kWh) per computer per year by simply turning off computers when not in use. A typical computer and monitor use 200 kWh when active and only 2 to 3 watts in sleep mode. Using the UM electricity rate of $0.07/kWh against the1,200 computers and laptops at Ross, and considering hours of operation and typical use pattern, Ross would conservatively save $20,000 per year. Basic power management for the Ross environment also saves 1,500 trees and effectively removes 80 automobiles from the roads each year through lower CO2 emissions. Finally, basic power management prolongs battery life for laptops, reduces total building cooling requirements, reduces noise, and reduces operating costs for energy and cooling.