Basic Navigation and Offline Browsing

Getting around in HyperLink

HyperLink is not really a document viewer at all, but instead an interpreter for a programming language called LinkScript. The HLPP proxy used for web browsing converts HTML into LinkScript for HyperLink to execute. When you view HyperLink pages, you are really running small programs that tell HyperLink what to display.

Here is a screenshot of HyperLink showing a typical document. At the top of the screen is a button bar; your pointer is in the upper left quadrant; and two scroll icons are on the left.

The scroll icons allow you to scroll through the document. Because you are really executing a small program, they act more like stop and run commands. The scroll down icon continues the document, functionally displaying the next page. The scroll up icon starts the document from the beginning (for technical reasons, it is not possible to scroll backwards without starting over).

The five icons on the button bar are identical to those in HL2.0 and are as follows:

• The green back arrow takes you to the last document you visited before this one. HL2.5 remembers a chain of up to ten documents.
• The light blue opening folder icon allows you to enter a filename or URL to open. This option is only valid for registered users. Users of the unregistered evaluation version cannot enter filenames or URLs directly, but may only click on links. If you enter a filename of a LinkScript file, the lnk. prefix will be added for you automatically. If you enter a Web URL starting with http://, HL2.5 will automatically try to connect to the Internet if you are not presently connected. Refer to the section on "Browsing the Web with HyperLink". If you make a mistake, you can press F7 to cancel.
• The grey home icon takes you to the home script on the current disk. This allows you to launch applications written for HyperLink just by inserting their disk and clicking the home icon. When you go home, the history of places you have visited is cleared, but your connection to the Internet is maintained if you are currently connected. To go back to the HyperLink home page, make sure the HL2.5 disk is in the primary disk drive and click the home icon.
• The white Computer Workshops diamond icon takes you to the information/about script on the current disk. This allows you to get information about the scripts on the disk you're using. To view the HyperLink credits and information page, make sure the HL2.5 disk is in the primary disk drive and click the about icon. To go back, just click the back icon to return to the document you were originally viewing.
• The pink question mark icon takes you to the online help facility on the current disk. This allows you to get online help with the disk you're using. To view HyperLink's built-in manual, make sure the HL2.5 disk is in the primary disk drive and click the help icon. To go back, just click the back icon (repeatedly if needed) to return to the document you were originally viewing.

HL2.5 provides additional keyboard commands:

• The = key (equals sign) displays the filename or URL of the document you are currently viewing, and the ten documents in your history sorted from most to least recently viewed (with 0 being the document you're viewing now). Press F7 to cancel, or any number key to jump immediately back that number of documents. Since 0 jumps you back no documents, it is effectively the same as cancelling. If you are using HL2.5a, it will also display its version number in the lower right corner.
• The CTRL-COMMODORE key combination halts a network transfer. See the section on "Browsing the Web with HyperLink".
• The CTRL-R key combination reloads the current document. If the document had been cached in memory, it is cleared from the cache and a new copy is fetched.
• The CTRL-K key combination toggles on and off system access to any script you display. Refer to the section "Offline browsing with HyperLink".
• If you see <Searchable> in the text area, the document is permitting you to send it additional information. Press S to search or query the document; if you make a mistake, you can press F7 to cancel. The document will tell you what information it is requesting. Both online and offline documents can be made searchable. (Note that until <Searchable> appears, the document cannot yet be queried and the S key will be ignored. The program displaying the document may have additional preparation to do first before it will permit you to send a query.)

Offline browsing with HyperLink

Offline applications can display I3-format inline images, can accept queries and may include their own built-in online help facilities. To view the online help in the application, press F1. In addition, offline applications can also execute external machine language programs to play music, do animation, or even create entire documents on the fly.

To run a specific file on a disk (registered users only), press F3 or click the open icon, and enter the filename. The lnk. prefix will be added for you.

A note on security: Because offline applications are permitted to install and run their own extensions, it is possible for an unscrupulous programmer to use them to cause damage to your system. If you don't trust the source of a script, you can use the CTRL-K key combination to toggle on and off whether a script may alter memory or load its own extensions. By default, these operations are allowed. Pressing CTRL-K once will disallow these operations and the border will briefly flash red, and any scripts that try to use active operations will display <Active> in the text area when such commands are encountered. Pressing CTRL-K again will again allow these operations and the border will briefly flash green. We would like to stress that such programs are rare, if not non-existent, and this measure is almost never needed; also, all of the scripts from Computer Workshops are fully tested and may be enjoyed safely with these operations enabled (the default).