- What are the size limits and PDF format restrictions on PDF files I can use?
- Filesize is determined by the memory handling facilities of the target devices. For PCs and Macs large file sizes (e.g. 100Mbytes or more) should work in most cases, but on mobile devices their memory handling is much less sophisticated and they slice the memory up into 64Mb chunks per application. We recommend that for distribution reasons (reliable downloading/fast downloading) and for memory management reasons, files should be kept to under 50Mb and preferably under 30Mb - the number of pages does not really matter - it can be 1000s. PDF files can be saved in a reduced size manner to ensure files are not too large and of course for screens (which have relatively low resolution) there is no need to use very hi-resolution print-ready PDF formats. Some publishing systems, like InDesign and Word, allowing you to export the content as "For screen display" or "Minimum filesize" so this is the recommended approach. If the files are still too large then we recommend splitting them into 2 or more "volumes". As the files are viewed interactively it is important to include a Contents list (also known as a bookmark tree or outline) for fast navigation, particularly for mobile devices. PDF files converted should not be set with Adobe-style protection and should not include embedded media such as 3D models or video clips. To provide video and audio support use links to separately hosted mp4 and mp3 files. See also our "All about PDF files" page: here
- What operating systems are supported?
- All modern mainstream operating systems and variants are supported in the Javelin end user software (secure PDF readers): MS Windows, Apple macOS/OSX, Apple iOS/iPadOS and Google Android. ChromeOS is not supported but Chromebooks can run Javelin3 for Android directly via its support for Android apps installed via the Android App Store. Unix platforms can be used if MSWindows virtualization software is provided. The DrumlinPublisher and AdminApp software requires MS Windows with .NET 4.5 or later. Windows 7 users who wish to take advantage of using the Javelin3 readers must make sure they have .NET 4.5 or later installed and associated updates to their operating system otherwise the program will not run (earlier versions of Javelin for Windows should then be used). Windows Server users with Remote Desktop (RDP) access should contact us for advice on implementation, but this environment is supported. Windows RT devices are not supported - a keyboard and mouse are required in most cases. Publishers and end users should be aware that each mainstream operating system has many variants and implementations, so it is vital that the appropriate version of Javelin for their target platform is installed. Some operating system and hardware setups may experience problems from time to time, e.g. after a major operating system "upgrade" and it is helpful to us if users and publishers report any such issues to us so we can check these
- Can other file formats, for example Word, Excel or PowerPoint, be converted and made secure?
- Yes - to convert Word, Excel or PowerPoint files they are typically first converted to PDF using the Export to PDF facility in the MS Office suite - this produces the best/highest quality results. With our online (webdoxx) service PDF and Powerpoint (PPT) files can be made available to standard web browser users via a secured HTML5 conversion with a range of access security controls
- How do authorization codes work to enable end users to view secured files?
When a publisher uses our free DrumlinPublisher software to create a new secure PDF in our encrypted format, the file itself (source PDF and encrypted PDF) remain on your local system. The DrumlinPublisher software exchanges metadata regarding the file with our DRM server, and the DRM server assigns the file a unique DocumentID or DocID when it is converted. This DocID information is stored within the DRM server and in an encrypted form within the secured PDF itself. The publisher in question also has a userID, so the DRM server also stores the ownership of every document alongside the DocID and other related data. When you want to make the secured file available (e.g. to sell it) to a third party, you need to provide them with the secure document itself, instructions for how to obtain the Javelin reader for their device, and details on how to download the file they have ordered. Let us suppose that the user purchases a document called myflightcourse.pdf and this has already been converted by you (or us on your behalf) to a secure (drmz) file, called myflightcourse.drmz and let us also suppose this document has been assigned a unique DocID of 123456 by our DRM server. In order for the user to be able to view the file they require some form of authorization, and to make this a very simple and automated process, the way this is done (as standard) is to provide the end user with an authorization code.
An authorization code is just a (random) text string that has been pre-generated via the Codes tab on the DrumlinPublisher software. DrumlinPublisher will only allow you to generate codes for files that you created/own, and when it generates a set of codes (e.g. 50 codes for 30 separate titles, so 1500 codes altogether - essentially this is simply a block of text strings, one per line, that are your current "stock" for these publications) each code includes on the DRM server details of the DocID it refers to and a usage count, typically 1 or 2 - this count specifies on how many devices the code can be used.
So now we have 50 codes for DocID 123456 and another 50 for another DocID etc. We load the codes onto our web server (or you do this on your web server or third party server) and then when the purchaser places an order for an item the cart system sends them a brief email, as you would for any product, but the email should include the next un-issued code from your stock for that particular DocID. Manual distribution of codes is also possible of course and is suitable for small volume sales. We have template email instructions and you can see the basic idea: here - The user follows the instructions, and when they first open the file it asks for a code for that file. The user enters the code and it is checked on our DRM server to make sure it is valid for that particular file and has a usage count > 0 and has not expired and is enabled. If it passes these checks the DRM server tells the user's device that it is OK to view that file and decrements the usage count on the DRM server record for that code, so if it started as 2 it would then be 1 and if it was 1 it would go to 0 and could no longer be used - in fact if someone tries to use a code that has a count of 0 that is also logged for you to see.
The above is the normal manner that publishers use the service - some publishers with only a few documents and small-scale sales issue the emails and codes manually, but most do so with an automated system of the kind previously described. Special facilities exist for dealing with courses that have many modules, common in many situations particularly in education and training - for example, it is possible to generate a block of codes for all 30 PDFs in a course set, where the text string for the code for each document is the same, e.g. abcdefghi, 123edf567 etc thus making it very simple for the end user and allowing for "bundle' products to be sold with a single code. Also note that codes can be disabled centrally and optionally reset to allow re-use (e.g. if a user changes device after a couple of years) and codes are NOT decryption keys - the files downloaded by end users remain encrypted even after authorization - this is because it is the DEVICE that is authorized to view the DocID in question, the file itself remains unaltered.
Now, when the end user authorizes the file it creates an activity log record on our DRM server and you have full access to this for your publications and clients - various end user actions are logged in this way, together with the date, time, ipaddress, device information, doc information etc. There are many facilities available with this model and it works extremely well for PDF publications across all the main tech platforms because it is so simple, requires very little service management, and there are no software costs involved, just fees for service usage.
- Can access to secured files be disabled?
Yes, there are a range of facilities to enable/disable access to files, even after they have been distributed and accessed by an end user. The principal mechanisms are reducing the usage count of the issued code to 0 and selecting the Disable code option in DrumlinPublisher via the Codes tab which sets the code status from 1 to 0 (disabled) and remotely disables furture access to the document for which the code has been issued.
- E-commerce: Do I need special software or services to use the Offline DRM service to sell books, newletters, newspapers etc?
- There are two main options: (i) accept orders via your existing e-commerce platform and then manually send an email to the customer with the authorization code they need for that file - this method is easy and ideal for small volume sales of one or two titles; or (ii) accept orders via some automated facility that send the emails out automatically, with the necessary authorization code included in the email. In this second scenario there are several options: (a) if your existing e-commerce system supports digital distribution with either "license codes" or "codes" etc then you can use that facility - for some e-commerce platforms this is a standard facility, for others it is available as a third-party add-ins or plug-ins, and for others it can be provided via a development using their toolsets and APIs (requires a developer of course); (b) there are several web-based services that specialize in providing digital distribution, including GetDPD, SendOwl, PayLoadz, Fetchapp and others. For Woocommerce users the license manager plugin can be used - see: Woocommerce License Manager; (c) for PayPal-based sales we can provide a managed service which enables you to sell direct from your website or via a catalog page on our website, with all purchase receipts going direct to your PayPal account (there is no commission charge from us for this service, although we do charge a setup cost and monthly service subscription for codes and support). For ecommerce service advice please see our E-commerce page and for subscription sales advice please see our Subscriptions page
- How do I send secured PDFs to end users?
- Secure (drmz) files can be sent to end users in several ways. The recommended method for multiple files delivered to multple platforms (desktop, laptop and mobile) is to use catalogs. See the Documentation page for more details. For single files delivered to desktops/laptops, simple file attachments to an email or provision of the file on a hosting service is fine (e.g. a web site, Shared drive or service like WeTransfer or even Dropbox). If users have problems downloading files on PCs or Macs they can be placed in a zip file first and then users can download the zipped copy (of one or more files) and unzip the ones they require. All Javelin readers also include a built-in downloader, so this can be used and is often suitable for single file distribution to mobile devices, although we recommend using very simple URLs and filenames to avoid end user problems with typing in the URL. Note that once a drmz file is generated you can change its name without affecting the file or its authorization or documentID - e.g. to a short name with no spaces or special characters. See also the email and download template samples we provided here
- What watermarking options are provided?
- PDF files can have a static watermark added to selected pages or all pages before converting to our secure offline format. A "tiled" or diagonal watermark on every page adds a significant level of additional security to the source file. Dynamic watermarks are displayed on the PDF pages, as an overlay, if set when the secure files are created. The content of the default dynamic watermark can include fixed text plus fields such as the authorization code, deviceID, logged in username etc. For more details please see the DrumlinPublisher manual. Special personalization facilities are also available that enable multiple files to be created in one go from a csv list, with each file named for the receipient and watermarked with additional information such as their full name, company etc. Our watermarks are secure and cannot be removed, unlike those with standard PDFs (e.g. with so-called PDF Stamping).
- Do the Javelin readers support markup and annotation?
- Yes, highlighting of text and adding of notes is supported for all platforms. However, because the PDF files are encrypted and remain encrypted they cannot be directly augmented with markup and annotation/notes, i.e. these elements are not stored within the secured PDF. Instead these elements are stored in separate files for each document, with pointers to where they should appear in the document. If the document is amended and re-issued or a new document provided with the same name but a different documentID, the elements 'may' no longer be available. For desktop users notes may be viewed as a list and optionally exported
- Do the Javelin readers support text to speech?
- Yes: Javelin3 for macOS (latest versions) supports text to speech via the the standard macOS "Settings" facility, "Dictation and Speech" option, with either page based reading aloud or when reading selected text regions. Javelin3 for Windows now supports read aloud facilities of Win8 and Win10 - right-clicking on a page provides the pop-up menu for speking the contents of the current page or selected text. Selected text is the recommended mode. Read aloud is also supported on mobile platforms via the menu facility or when text blocks are selected (Read page and Read selected text facilities)
- How long should file conversions take?
- Typically file conversion takes 1-2 seconds per file. Note that the source PDF file never leaves your site/is not uploaded to our DRM server, so remains secure on your site. Only metadata relating to the file is uploaded (e.g. your registered userID, the source PDF filename, the date/time of the conversion etc)
- Can I update an existing file I have issued and keep the same documentID?
- Yes, you can augment previously issued files, with corrections and/or additions, as long as you ensure that the newly generated file has exactly the same PDF filename as the previous one
- Can screen capture be disabled?
- This is probably the most frequent question we get asked. The short answer is "no", not 100% reliably, no matter whose systems and software you are using - the same issue applies to printed documents - they can always be scanned or photographed, even if attempts are made to prevent screen grab programs from being used on electronically displayed documents. We provide an option in DrumlinPublisher to specify screen capture disabling, which applies to Javelin3 for Windows and Javelin for MacOS usage, and deals with most program-driven screen grab attempts. On Javelin3 for Android the built-in hardware screen capture facility is always disabled, as this is an option provided within the Android operating system. On iOS/iPadOS screen capture is made difficult and cumbersome in the Javelin reader rather than prevented. However, with all OS variants we recommend NOT using the Disable Screen Capture option, particularly if the end users include corporate clients, but using dynamic watermarking, as noted in our Watermarking FAQ answer. This identifies the individual and device if/when a screen grab is made, strongly discouraging misuse of the captured image. We also provide a "personalization" facility within DrumlinPublisher, enabling even more specific personalization of secured files distributed to multiple end users. In our experience these are extremely effective measures to employ if publishers have real concerns about possible screen capture
- Is there a limit on the number of PDF files I can convert? And can I bulk convert files if I have lots?
- There is no limit on the number of files you can convert and there are bulk conversion facilities built into the DrumlinPublisher software (multi-file selection and conversion, plus folder-based multi-file selection)
- What filenames are accepted for conversion?
- Ideally filenames should be as simple and concise as possible, avoiding the use of special characters such as symbols, spaces, punctuation marks, accented characters or national variants, and using latin alphabet if possible. Files must be in standard PDF format and should not include Adobe-style protection. Once a secure PDF has been created (typically a drmz file) its naame can be altered (e.g. to a much simpler, all lower case name) without affecting its usage - the documentID that controls access is contained in an encrypted block within the file, so its filename is ignored by the reader software
- What security features are provided as standard?
- There are several elements to the security framework: (i) conversion of the source PDF to our secure 256-bit encryption formats; (ii) protection of the applications (Javelin readers) from hacking; (iii) control of access to documents on a device and/or user basis, with authorization code control as standard and license-based controls as optional for Corporate clients using the Windows platform; (iv) overlaid dynamic (optionally user-specific) watermarking; (v) usage tracking by user and document, including tracking of attempted misuse and of events such as printing and opening; (vi) all document handling takes place in memory so no insecure files are ever available on disk/permanent storage; (vii) https based communications and hosting (if we provide the file hosting environment); (viii) disabling of access when required, e.g. as a result of a person leaving an organization, abuse of file usage that has been idetified or suspected, or where a refund is requested after a suspicious purchase
- What are the pros and cons of Offline PDF security?
- PROs:(i)strongly encrypted files; (ii) optional secure printing; (iii) high speed display, zooming and text searching; (iv) usage tracking including attempts at misuse; (v) available for use offline with no internet connectivity; (vi) easy use across multiple devices; CONs: (i) requires installation of proprietary PDF reader (Javelin); (ii) initial authorization requires brief internet connectivity (not required for Corporate users of Pro editions of the Windows reader if license files supplied or for pre-authorized files)
- How does Date Expiry work?
- Start and end dates/Expires after: In most cases the Start Date will be today or earlier (e.g. 1/1/2020) and the end date will be a date long off into the future (e.g. 1/1/2040), but any suitable start and end dates can be specified – there is now an option to specify NO EXPIRY DATE in which case the expiry date is automatically set 200 years forward! Files that have an absolute expiry date cannot be re-enabled after they expire - a new file must be issued with a later expiry date. If a new version of the same document is created and distributed, any existing users of that document will need to use the Remove Authorization facility on their device before being able to view the updated version with a new or reset authorization code.
The “Expires after” option allows you to specify that a document can be read for a specified number of days (for example, up to 999 days maximum) from the date the file is authorized, and then it will expire. This is effectively like a document loan or rental – it provides a means of allowing an end user a fixed amount of time to view the file. A file that has expired as a result of an "Expires after nnn days" can be renewed simply by provision of a new, or re-enabled, authorization code for that file, or a multiple usage code. Authorization codes do not control the expiry dates, but for Corporate/Pro users License files can be used to take precedence over the start/end date settings
- Can printing be enabled? And if so, what are the recommended settings?
- Yes, printing can be enabled for desktop and laptop devices (Windows and macOS versions of Javelin) but we recommend it is only enabled if necessary - printing can be of all pages or a specified number of pages (i.e. across multiple print attempts) and can include static and dynamic watermarking. Double-sided printing is not supported. Printing should be to devices that are directly attached (i.e. not WiFi connected). Use of third party printshops and similar services is not recommended as these will not be able to provide the print functionality they would normally offer. Protection is provided against attempts to print to non-physical devices (e.g.PDF and Image writers, software services that deliver print functionality). We recommend that publishers set the Print Count to "unlimited" and then the Print pages count to the total number of pages they wish to allow the user to print. e.g. with a 100 page document printable twice, you might allow 200 or 250 pages to be printed. The reason for doing this is that an end user may print 1 page as a test, then decide to print 10 pages, then another 10 etc and that would be 3 print events, so if you set the print count to 3 they would no longer be able to print - also, many users have problems when printing, such as paper jams, running out of ink etc, so may have to print more times than you expect. We also recommend that only a few pages are p[rinted at a time, e.g. blocks of 10-50 pages max, and if there are problems, cut the number printed at once down, starting with a single page to check it is working as expected. Javelin3 for Windows includes a Tools menu, Settings facility to adjust print scaling and resolution. Please see the documentation for guidance on all aspects including printing, available via the Documentation page on our website or directly: here - page 6 relates to printing. If a user has a problem because the print count has expired, then they can use the Javelin reader's File menu, Remove authorization option to clear their settings, and then re-open the document and re-enter a valid authorization code for that file, and they will have a new quota of printing based on the settings made for that file when it was generated
- Can PDFs include embedded videos or other media?
- Embedded media can result in some PDF files being very large and also requires the use of specific PDF readers, because such embedding is non-standard and typically Adobe-specific. For details on how to do this using Adobe Acrobat see: https://helpx.adobe.com/acrobat/using/rich-media.php - Solutions to making media-enabled PDFs available more widely and/or with content protection include: retaining the source PDF but replacing the embedded media with links to externally hosted media files (typically web-hosted streaming facilities such as Vimeo or pure MP3 or MP4 hosted files); automated conversion of the PDF to HTML5 with embedded media; or conversion of the PDF to HTML5 with linked media; we provide solutions for all these options, including solutions (with full support for transitions and animations) for Powerpoint files, all with content protection facilities. Please contact us for more details if these solutions look like meeting a new or existing requirement for your books or training publications.
- My secured file is enabled for printing but I get a message saying I cannot print to the device I have specified?
- Protection is provided against attempts to print to non-physical devices (e.g.PDF and Image writers, in-network software print services). The software does this using a large list of known valid printers so it may be that the printer you are trying to use is not recognized, or that the operating system is trying to print to a "nominal" print device with a naming that is not a known printer or an in-network software service that may provide printing but is not a physical printer. In all these cases you can either (i) attach your device to a physical printer using a cable (e.g. USB) if that is possible; or (ii) use another device, e.g. at home, which has a real printer attached; or (iii) ask the publisher if a printed copy is available; or (iv) use the file on a tablet device (i.e. portable) in lieu of being able to print. If necessary you can also use the File menu, Log file option and then send us the log file to check. If the device details do indicate a genuine "new" printer device then we can enable this for you with a software update
- What prevents the end user providing the secured PDF and their authorization code to someone else to use?
- When a secured PDF (drmz file) is authorized the file remains encrypted - it is the device that is enabled to view that specific file. If the authorization code has a usage count of 1 initially and the end user has authorized their file, the usage count available will be 0, so the code will no longer be valid. Sending the secured file and the authorization code to someone else to use will fail and any attempt to do this will be logged centrally and is available to publishers to check. If a license file rather than an authorization code has been provided to the end user, the license file is unusable on any other device so again protects the secured PDF file from misuse
- Can I add my own branding to the Javelin viewer?
- Branded versions of the Javelin3 and/or Javelin3Pro Windows reader can be amended to provided a level of branding. Standard branding includes: branded/tailored opening screen; selectable toolbar elements; color selectable catalog header and background; branded icons in program including About form and catalogs; renamed program; bespoke installation kit. Excludes special requested developments and ongoing updates. Contact us for more details and a quotation and/or see the Pricing menu, One-time purchases
- Can I host the converted PDF for use on my own servers?
- Yes, the drmz files are simply files that are available and encrypted. Links to drmz file can be protected, e.g. with secured links and/or by making them available behind an access control facility, but in general this is not necessary because the files always remain encrypted.
- Can I make Javelin3 my default PDF reader on Windows and/or macOS?
- Yes, on Windows try the following:
Windows Option 1: simply select a PDF in Windows Explorer and right click and select Open With... and choose Javelin3 (if listed), or if not shown, select "Choose another app" and Scroll down and you will see a link "More apps .... Look for another app on this PC" - select the "Program Files(x86)" folder and choose Javelin3.exe and tick the option to always open PDF files with the selected app; You can also do this via the file Properties option, where you will see an open with... option
Windows Option 2 (for some versions of Windows): Click on the Start button and select the Settings cog; In the Windows Settings display, select Apps; The Set Default Programs window will open; Under the list of programs click on Javelin3; Choose Set this program as default; Select OK:
macOS: Right-click on a file that uses the file type you'd like to change the default for. ... i.e. any PDF you select in Finder; Click on Get Info in the pop-up; Click Open With if the section isn't already expanded; Click the dropdown and choose an app... in this case Javelin3; Click Change All... so all PDF files will now open in Javelin3
- If I take out a subscription what happens if I want to cancel or suspend my subscription?
- Subscriptions are monthly (or can be paid for annually in advance) and can be cancelled at any time. Document details and codes for publications that have been generated and issued to end users will be retained and supported for a period but publisher access to service management and code generation facilities will cease.
- Can I change my subscription (upgrade or downgrade the service level)?
- You can change your subscription at any time - simply take out a new subscription using the same email address as before to replace your current subscription service level, or use a new email address to create an additonal (new) subscription and then cancel the previous subscription via PayPal, Worldpay or contact us to cancel your old subscription on your behalf
- My customer is using a current version of Javelin but cannot access the service - what is the problem?
- The probability is that their network is blocking access to or from our DRM server. Please see the Help on common issues, item 3, for details on how to resolve this
- I just downloaded Javelin for an ebook I purchased. However now every pdf is automatically getting associated with the Javelin3 PDF reader. Any guidance on how to rectify this would be greatly appreciated
- This can happen with Android-based devices, because when you initially download and open a PDF on Android, it asks you which PDF reader you want to use, either Just Once or Always, and if you answer "Always" it will remember that as the default. That can be changed via the Settings facility on an Android device, apps section, and select the app (Javelin3) to see the facilities and settings, which can then be changed. On a PC this would normally only occur if you have selected (but not opened) a PDF in Windows Explorer, right clicked on the filename and used the OPEN WITH... option to select the program you want to use - if the option box is ticked to SET AS DEFAULT that would choose the selected program for all subsequent PDFs, but you can change to another one at any time by going through the same steps
- One of our trainees wants to do a reset of his PC laptop and he is already using Javelin3 PDF reader for his studies. He wants to know how to retain the highlighted content and annotation he done to all the PDFs we have shared with him
- On the PC version of Javelin3 there is a special option for this via the File menu - if a secured document with annotations is opened, there is an option "Create Backup Copy" - this creates a special file that includes both the document and any annotations, which can be saved on an external disk for example. The user can then use another PC or the same PC (even if the latter has had its operating system re-installed), and they can then use the File menu, Restore Backup option to restore the file they have saved. If in doubt they can test this works on another PC first, just to make sure it all looks OK. The only thing that would need to be done in this case is that the file or files will need to be re-authorized if the registry entries have been cleared. This is documented in the Javelin3 user guide, page 28, available locally or online at: here
- Can Javelin3 for Windows be installed "silently"?
- YES ... within the InnoSetup install program there are options for silent installation - please see Inno Setup Command Line Parameters: e.g. "Javelin22.214.171.124setup.exe /verysilent /suppressmsgboxes /norestart /allusers". If this is done from an Administrator shell, then no UI interaction at all takes place as the system message box "Do you want to allow this app to make changes to your device?" is not required. Note that both the installed images and the setup executables are digitally signed with GlobalSign EV certificates
- I have an end user who wants to transfer his secure ebook from his existing PC to a new PC, together with the notes and markup he has added. Can this be done with Javelin3 for Windows?
- Using Javelin3 for Windows, there is a special function to support this - the user can open the document and select the File menu, Create Backup copy, and this will produce a special backup file that includes the original document plus the associated annots file with the markup and notes created by the user. This backup file can then be taken to another PC and with the File menu, Restore Backup the file and its annots can be re-instated. However, if installed on a new PC (or an old PC with its registry re-installed) the file will need to be re-authorized (i.e., with a reset code or new code) because it would not be recognized on that device
- Why is Javelin3 for Mac not available on the Mac App Store?
- On the Mac many apps are not provided on the Apple App Store, for a variety of reasons (commercial, technical, practical, 'political' etc.) - this includes Adobe PDF Reader, for example. Like the Javelin3 reader for Mac, the Adobe reader is provided as a signed, downloadable file, and works just fine on Mac platforms (for example, see the Adobe site for more details). The Javelin3 reader, which is free, is produced by us with Apple's approval for us as a Mac developer and uses Apple's PDF Library for the document display handling, so is essentially a secure version of the Preview app issued by Apple themselves. We update it whenever necessary, but it tends not to require changing unless Apple have a major problem themselves, or they completely change their operating system architecture and library, which generally only occurs every few years and tends to require new versions of all their software as well as everyone else's if the user chooses to upgrade their operating system - often Apple do not provide backward compatibility, forcing users to purchase new hardware and/or software, whereas we do provide multiple versions to provide full backward compatibility.
- Can secured PDFs be accessed on multiple devices?
- "Yes" - but it really depends on the choices made when publishing secured files, whether offline or online. With offline usage, by specifying an authorization code as just one usage, then access is limited to a single device, but often publishers will set the value as 2, so a desktop or laptop plus a mobile device for that end user is permitted. In special cases, for example in a closed classroom envirnment with many students in attendance, a much higher value is sometimes specified (e.g. 30) to allow a single code to be used for all students in a class, which is then disabled (set back to 0) after its initial use in the classroom or lecture theatre. With online (web-based) access, unlimited access can be provided by not requiring logins, or limited access can be selected by specifying a limit on the number of browsers permitted to access the file by one logged in user (e.g. on different devices), or by restricting the number of simultaneous sessions for that user
- What is the Terminal application on Mac computers for, and why do some apps close when the Terminal app is running?
- Most MacOS users are unaware of the built-in app called Terminal. It effectively provides direct access to the operating system, rather like the CMD and Shell facilities provided in the Windows operating system. Most of the time, if Terminal is running, it forms part of a start-up process setup by an IT Department, for example to facilitate access to some in-network facilities, and is quite common on University campus-based systems. Unfortunately it also provides a backdoor for would-be hackers to attack the operating system and its memory handling, and for that reason when Javelin3 for Mac is run, it will close itself with a warning message and not allow secure documents to be viewed unless the Terminal app is closed first