Silicon ChipComputer Bits - September 1991 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: The future of electronic mail
  4. Feature: The Highs & Lows Of A/D & D/A Conversion by Darren Yates
  5. Feature: Plotting The Course Of Thunderstorms by Leo Simpson
  6. Project: Studio 3-55L 3-Way Loudspeaker System by Greg Swain
  7. Project: Digital Altimeter For Gliders & Ultralights, Pt.1 by John Clarke
  8. Serviceman's Log: I'd never seen that one before by The TV Serviceman
  9. Subscriptions
  10. Order Form
  11. Project: Build A Fax/Modem For Your Computer by Leo Simpson
  12. Feature: Computer Bits by Jennifer Bonnitcha
  13. Project: Ultrasonic Switch For Mains Appliances by Jeff Monegal
  14. Feature: Amateur Radio by Garry Cratt, VK2YBX
  15. Vintage Radio: Transistor radios are worth collecting by John Hill
  16. Back Issues
  17. Feature: The Story Of Electrical Energy; Pt.13 by Bryan Maher
  18. Market Centre
  19. Advertising Index
  20. Outer Back Cover

This is only a preview of the September 1991 issue of Silicon Chip.

You can view 44 of the 96 pages in the full issue, including the advertisments.

For full access, purchase the issue for $10.00 or subscribe for access to the latest issues.

Articles in this series:
  • Digital Altimeter For Gliders & Ultralights, Pt.1 (September 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.1 (September 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.2 (October 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.2 (October 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.3 (November 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.3 (November 1991)
Articles in this series:
  • Computer Bits (July 1989)
  • Computer Bits (July 1989)
  • Computer Bits (August 1989)
  • Computer Bits (August 1989)
  • Computer Bits (September 1989)
  • Computer Bits (September 1989)
  • Computer Bits (October 1989)
  • Computer Bits (October 1989)
  • Computer Bits (November 1989)
  • Computer Bits (November 1989)
  • Computer Bits (January 1990)
  • Computer Bits (January 1990)
  • Computer Bits (April 1990)
  • Computer Bits (April 1990)
  • Computer Bits (October 1990)
  • Computer Bits (October 1990)
  • Computer Bits (November 1990)
  • Computer Bits (November 1990)
  • Computer Bits (December 1990)
  • Computer Bits (December 1990)
  • Computer Bits (January 1991)
  • Computer Bits (January 1991)
  • Computer Bits (February 1991)
  • Computer Bits (February 1991)
  • Computer Bits (March 1991)
  • Computer Bits (March 1991)
  • Computer Bits (April 1991)
  • Computer Bits (April 1991)
  • Computer Bits (May 1991)
  • Computer Bits (May 1991)
  • Computer Bits (June 1991)
  • Computer Bits (June 1991)
  • Computer Bits (July 1991)
  • Computer Bits (July 1991)
  • Computer Bits (August 1991)
  • Computer Bits (August 1991)
  • Computer Bits (September 1991)
  • Computer Bits (September 1991)
  • Computer Bits (October 1991)
  • Computer Bits (October 1991)
  • Computer Bits (November 1991)
  • Computer Bits (November 1991)
  • Computer Bits (December 1991)
  • Computer Bits (December 1991)
  • Computer Bits (January 1992)
  • Computer Bits (January 1992)
  • Computer Bits (February 1992)
  • Computer Bits (February 1992)
  • Computer Bits (March 1992)
  • Computer Bits (March 1992)
  • Computer Bits (May 1992)
  • Computer Bits (May 1992)
  • Computer Bits (June 1992)
  • Computer Bits (June 1992)
  • Computer Bits (July 1992)
  • Computer Bits (July 1992)
  • Computer Bits (September 1992)
  • Computer Bits (September 1992)
  • Computer Bits (October 1992)
  • Computer Bits (October 1992)
  • Computer Bits (November 1992)
  • Computer Bits (November 1992)
  • Computer Bits (December 1992)
  • Computer Bits (December 1992)
  • Computer Bits (February 1993)
  • Computer Bits (February 1993)
  • Computer Bits (April 1993)
  • Computer Bits (April 1993)
  • Computer Bits (May 1993)
  • Computer Bits (May 1993)
  • Computer Bits (June 1993)
  • Computer Bits (June 1993)
  • Computer Bits (October 1993)
  • Computer Bits (October 1993)
  • Computer Bits (March 1994)
  • Computer Bits (March 1994)
  • Computer Bits (May 1994)
  • Computer Bits (May 1994)
  • Computer Bits (June 1994)
  • Computer Bits (June 1994)
  • Computer Bits (July 1994)
  • Computer Bits (July 1994)
  • Computer Bits (October 1994)
  • Computer Bits (October 1994)
  • Computer Bits (November 1994)
  • Computer Bits (November 1994)
  • Computer Bits (December 1994)
  • Computer Bits (December 1994)
  • Computer Bits (January 1995)
  • Computer Bits (January 1995)
  • Computer Bits (February 1995)
  • Computer Bits (February 1995)
  • Computer Bits (March 1995)
  • Computer Bits (March 1995)
  • Computer Bits (April 1995)
  • Computer Bits (April 1995)
  • CMOS Memory Settings - What To Do When The Battery Goes Flat (May 1995)
  • CMOS Memory Settings - What To Do When The Battery Goes Flat (May 1995)
  • Computer Bits (July 1995)
  • Computer Bits (July 1995)
  • Computer Bits (September 1995)
  • Computer Bits (September 1995)
  • Computer Bits: Connecting To The Internet With WIndows 95 (October 1995)
  • Computer Bits: Connecting To The Internet With WIndows 95 (October 1995)
  • Computer Bits (December 1995)
  • Computer Bits (December 1995)
  • Computer Bits (January 1996)
  • Computer Bits (January 1996)
  • Computer Bits (February 1996)
  • Computer Bits (February 1996)
  • Computer Bits (March 1996)
  • Computer Bits (March 1996)
  • Computer Bits (May 1996)
  • Computer Bits (May 1996)
  • Computer Bits (June 1996)
  • Computer Bits (June 1996)
  • Computer Bits (July 1996)
  • Computer Bits (July 1996)
  • Computer Bits (August 1996)
  • Computer Bits (August 1996)
  • Computer Bits (January 1997)
  • Computer Bits (January 1997)
  • Computer Bits (April 1997)
  • Computer Bits (April 1997)
  • Windows 95: The Hardware That's Required (May 1997)
  • Windows 95: The Hardware That's Required (May 1997)
  • Turning Up Your Hard Disc Drive (June 1997)
  • Turning Up Your Hard Disc Drive (June 1997)
  • Computer Bits (July 1997)
  • Computer Bits (July 1997)
  • Computer Bits: The Ins & Outs Of Sound Cards (August 1997)
  • Computer Bits: The Ins & Outs Of Sound Cards (August 1997)
  • Computer Bits (September 1997)
  • Computer Bits (September 1997)
  • Computer Bits (October 1997)
  • Computer Bits (October 1997)
  • Computer Bits (November 1997)
  • Computer Bits (November 1997)
  • Computer Bits (April 1998)
  • Computer Bits (April 1998)
  • Computer Bits (June 1998)
  • Computer Bits (June 1998)
  • Computer Bits (July 1998)
  • Computer Bits (July 1998)
  • Computer Bits (November 1998)
  • Computer Bits (November 1998)
  • Computer Bits (December 1998)
  • Computer Bits (December 1998)
  • Control Your World Using Linux (July 2011)
  • Control Your World Using Linux (July 2011)
Articles in this series:
  • Amateur Radio (November 1987)
  • Amateur Radio (November 1987)
  • Amateur Radio (December 1987)
  • Amateur Radio (December 1987)
  • Amateur Radio (February 1988)
  • Amateur Radio (February 1988)
  • Amateur Radio (March 1988)
  • Amateur Radio (March 1988)
  • Amateur Radio (April 1988)
  • Amateur Radio (April 1988)
  • Amateur Radio (May 1988)
  • Amateur Radio (May 1988)
  • Amateur Radio (June 1988)
  • Amateur Radio (June 1988)
  • Amateur Radio (July 1988)
  • Amateur Radio (July 1988)
  • Amateur Radio (August 1988)
  • Amateur Radio (August 1988)
  • Amateur Radio (September 1988)
  • Amateur Radio (September 1988)
  • Amateur Radio (October 1988)
  • Amateur Radio (October 1988)
  • Amateur Radio (November 1988)
  • Amateur Radio (November 1988)
  • Amateur Radio (December 1988)
  • Amateur Radio (December 1988)
  • Amateur Radio (January 1989)
  • Amateur Radio (January 1989)
  • Amateur Radio (April 1989)
  • Amateur Radio (April 1989)
  • Amateur Radio (May 1989)
  • Amateur Radio (May 1989)
  • Amateur Radio (June 1989)
  • Amateur Radio (June 1989)
  • Amateur Radio (July 1989)
  • Amateur Radio (July 1989)
  • Amateur Radio (August 1989)
  • Amateur Radio (August 1989)
  • Amateur Radio (September 1989)
  • Amateur Radio (September 1989)
  • Amateur Radio (October 1989)
  • Amateur Radio (October 1989)
  • Amateur Radio (November 1989)
  • Amateur Radio (November 1989)
  • Amateur Radio (December 1989)
  • Amateur Radio (December 1989)
  • Amateur Radio (February 1990)
  • Amateur Radio (February 1990)
  • Amateur Radio (March 1990)
  • Amateur Radio (March 1990)
  • Amateur Radio (April 1990)
  • Amateur Radio (April 1990)
  • Amateur Radio (May 1990)
  • Amateur Radio (May 1990)
  • Amateur Radio (June 1990)
  • Amateur Radio (June 1990)
  • Amateur Radio (July 1990)
  • Amateur Radio (July 1990)
  • The "Tube" vs. The Microchip (August 1990)
  • The "Tube" vs. The Microchip (August 1990)
  • Amateur Radio (September 1990)
  • Amateur Radio (September 1990)
  • Amateur Radio (October 1990)
  • Amateur Radio (October 1990)
  • Amateur Radio (November 1990)
  • Amateur Radio (November 1990)
  • Amateur Radio (December 1990)
  • Amateur Radio (December 1990)
  • Amateur Radio (January 1991)
  • Amateur Radio (January 1991)
  • Amateur Radio (February 1991)
  • Amateur Radio (February 1991)
  • Amateur Radio (March 1991)
  • Amateur Radio (March 1991)
  • Amateur Radio (April 1991)
  • Amateur Radio (April 1991)
  • Amateur Radio (May 1991)
  • Amateur Radio (May 1991)
  • Amateur Radio (June 1991)
  • Amateur Radio (June 1991)
  • Amateur Radio (July 1991)
  • Amateur Radio (July 1991)
  • Amateur Radio (August 1991)
  • Amateur Radio (August 1991)
  • Amateur Radio (September 1991)
  • Amateur Radio (September 1991)
  • Amateur Radio (October 1991)
  • Amateur Radio (October 1991)
  • Amateur Radio (November 1991)
  • Amateur Radio (November 1991)
  • Amateur Radio (January 1992)
  • Amateur Radio (January 1992)
  • Amateur Radio (February 1992)
  • Amateur Radio (February 1992)
  • Amateur Radio (March 1992)
  • Amateur Radio (March 1992)
  • Amateur Radio (July 1992)
  • Amateur Radio (July 1992)
  • Amateur Radio (August 1992)
  • Amateur Radio (August 1992)
  • Amateur Radio (September 1992)
  • Amateur Radio (September 1992)
  • Amateur Radio (October 1992)
  • Amateur Radio (October 1992)
  • Amateur Radio (November 1992)
  • Amateur Radio (November 1992)
  • Amateur Radio (January 1993)
  • Amateur Radio (January 1993)
  • Amateur Radio (March 1993)
  • Amateur Radio (March 1993)
  • Amateur Radio (May 1993)
  • Amateur Radio (May 1993)
  • Amateur Radio (June 1993)
  • Amateur Radio (June 1993)
  • Amateur Radio (July 1993)
  • Amateur Radio (July 1993)
  • Amateur Radio (August 1993)
  • Amateur Radio (August 1993)
  • Amateur Radio (September 1993)
  • Amateur Radio (September 1993)
  • Amateur Radio (October 1993)
  • Amateur Radio (October 1993)
  • Amateur Radio (December 1993)
  • Amateur Radio (December 1993)
  • Amateur Radio (February 1994)
  • Amateur Radio (February 1994)
  • Amateur Radio (March 1994)
  • Amateur Radio (March 1994)
  • Amateur Radio (May 1994)
  • Amateur Radio (May 1994)
  • Amateur Radio (June 1994)
  • Amateur Radio (June 1994)
  • Amateur Radio (September 1994)
  • Amateur Radio (September 1994)
  • Amateur Radio (December 1994)
  • Amateur Radio (December 1994)
  • Amateur Radio (January 1995)
  • Amateur Radio (January 1995)
  • CB Radio Can Now Transmit Data (March 2001)
  • CB Radio Can Now Transmit Data (March 2001)
  • What's On Offer In "Walkie Talkies" (March 2001)
  • What's On Offer In "Walkie Talkies" (March 2001)
  • Stressless Wireless (October 2004)
  • Stressless Wireless (October 2004)
  • WiNRADiO: Marrying A Radio Receiver To A PC (January 2007)
  • WiNRADiO: Marrying A Radio Receiver To A PC (January 2007)
  • “Degen” Synthesised HF Communications Receiver (January 2007)
  • “Degen” Synthesised HF Communications Receiver (January 2007)
  • PICAXE-08M 433MHz Data Transceiver (October 2008)
  • PICAXE-08M 433MHz Data Transceiver (October 2008)
  • Half-Duplex With HopeRF’s HM-TR UHF Transceivers (April 2009)
  • Half-Duplex With HopeRF’s HM-TR UHF Transceivers (April 2009)
  • Dorji 433MHz Wireless Data Modules (January 2012)
  • Dorji 433MHz Wireless Data Modules (January 2012)
Articles in this series:
  • The Technology Letters, Pt.2 (January 1989)
  • The Technology Letters, Pt.2 (January 1989)
  • The Story Of Electrical Energy (July 1990)
  • The Story Of Electrical Energy (July 1990)
  • The Story Of Electrical Energy; Pt.2 (August 1990)
  • The Story Of Electrical Energy; Pt.2 (August 1990)
  • The Story Of Electrical Energy; Pt.3 (September 1990)
  • The Story Of Electrical Energy; Pt.3 (September 1990)
  • The Story Of Electrical Energy; Pt.4 (October 1990)
  • The Story Of Electrical Energy; Pt.4 (October 1990)
  • The Story Of Electrical Energy; Pt.5 (November 1990)
  • The Story Of Electrical Energy; Pt.5 (November 1990)
  • The Story Of Electrical Energy; Pt.6 (December 1990)
  • The Story Of Electrical Energy; Pt.6 (December 1990)
  • The Story Of Electrical Energy; Pt.7 (January 1991)
  • The Story Of Electrical Energy; Pt.7 (January 1991)
  • The Story Of Electrical Energy; Pt.8 (February 1991)
  • The Story Of Electrical Energy; Pt.8 (February 1991)
  • The Story Of Electrical Energy; Pt.9 (March 1991)
  • The Story Of Electrical Energy; Pt.9 (March 1991)
  • The Story Of Electrical Energy; Pt.10 (May 1991)
  • The Story Of Electrical Energy; Pt.10 (May 1991)
  • The Story Of Electrical Energy; Pt.11 (July 1991)
  • The Story Of Electrical Energy; Pt.11 (July 1991)
  • The Story Of Electrical Energy; Pt.12 (August 1991)
  • The Story Of Electrical Energy; Pt.12 (August 1991)
  • The Story Of Electrical Energy; Pt.13 (September 1991)
  • The Story Of Electrical Energy; Pt.13 (September 1991)
  • The Story Of Electrical Energy; Pt.14 (October 1991)
  • The Story Of Electrical Energy; Pt.14 (October 1991)
  • The Story Of Electrical Energy; Pt.15 (November 1991)
  • The Story Of Electrical Energy; Pt.15 (November 1991)
  • The Story Of Electrical Energy; Pt.16 (December 1991)
  • The Story Of Electrical Energy; Pt.16 (December 1991)
  • The Story Of Electrical Energy; Pt.17 (January 1992)
  • The Story Of Electrical Energy; Pt.17 (January 1992)
  • The Story Of Electrical Energy; Pt.18 (March 1992)
  • The Story Of Electrical Energy; Pt.18 (March 1992)
  • The Story Of Electrical Energy; Pt.19 (August 1992)
  • The Story Of Electrical Energy; Pt.19 (August 1992)
  • The Story of Electrical Energy; Pt.20 (September 1992)
  • The Story of Electrical Energy; Pt.20 (September 1992)
  • The Story Of Electrical Energy; Pt.21 (November 1992)
  • The Story Of Electrical Energy; Pt.21 (November 1992)
  • The Story Of Electrical Energy; Pt.22 (January 1993)
  • The Story Of Electrical Energy; Pt.22 (January 1993)
  • The Story of Electrical Energy (April 1993)
  • The Story of Electrical Energy (April 1993)
  • The Story Of Electrical Energy; Pt.24 (May 1993)
  • The Story Of Electrical Energy; Pt.24 (May 1993)
  • The Story Of Electrical Energy; Pt.24 (June 1993)
  • The Story Of Electrical Energy; Pt.24 (June 1993)
COMPUTER BITS BY JENNIFER BONNITCHA Swapfiles, program groups & icons After you have instal~ed Windows, you can easily customise it to suityour requirements. This month, we show you how to create new program groups & items. Windows 3.0 probably has the smartest installation routine around - but it's not always as smart as it could be. Setup scans the CONFIG.SYS and AUTOEXEC.BAT files to disable utilities it thinks will conflict with Windows and where possible it replaces them with its own Windowscompatible versions. If you use TSRs (Terminate and Stay Resident programs) such as SideKick, you should remove the appropriate lines from AUTOEXEC.BAT. You can use TSRs with Windows but you should load them after Windows is running. Before installing Windows, it's a good idea to make a copy of the AUTOEXEC.BAT and CONFIG.SYS files so that you can check them against the installed versions. Once you have installed Windows .Eile 66 .Qptions Window New program groups The Program Manager's menu bar contains four options: File, Options, Window and Help. Rather than having Windows separate your applications into Windows and Non-Windows applications, you may want to group all your frequently used applications together. You can easily create a new Program Group by selecting File then New from the Program Manager menu bar. Fig.1: the Program Manager window gives you access to the other Program Groups (along the bottom of the screen) & is central to the operation of Windows. It runs continuously in the background,evenif other applications are selected. !::felp rnifil rnifil Games Non Windows SILICON CHIP and started the program, you are presented with a desktop containing many icons (pictures). These icons are the items you select to perform various tasks. You will usually see the Program Manager and any associated Program Groups. You can think of the Program Manager as a kind of shell for Windows because all applications run under and are controlled by the Program Manager. It is from this main window that you are able to access other Program Groups and options (Fig.1). Thus, the Program Manager is central to those operations that enable the execution of Windows and Non-Windows Applications and utilities. It also manages your computer resources so you can have more than one application running at the same time. Although you can minimise the Program Manager, it is always running in the background until you exit from Windows. The Program Manager is responsible for setting up and supervising any applications you want to run under Windows - a set of related applications or programs is called a Program Group. The Program Manager initially contains five Program Groups - Main, Accessories, Windows Applications, Non-Windows Applications and Games. All the applications in the Accessories window, for example, form a Program Group (Fig.2). ffi Applications ~ ~ ffi Main Accessories Fil ~ • ~ Write Win Paintbrush Terminal ll!J!D Uillil. Calendar Calculator 6 Cardfile ~ mm mm Games Non Windows Windows then displays the New Program Object dialog box (Fig.3) which allows you to create either a new Program Group (a collection of related applications) or Program Item (a single application within a Program Group). Select Program Group if necessary, then click on OK. Next, Windows needs to know about the intended purpose of the Program Group (Fig.4) by means of a Description (Windows normally fills in the Group File section for you) such as My Apps. Once you choose OK, you are ready to place Program Items into your new Program Group. Copying & moving icons You can move program icons according to your own preferences. You could group all your commonly used applications in the above My Apps Program Group rather than using Windows ' separate groups. You could also place commonly used accessories such as the card file or calculator into My Apps. You can move icons from one group to another by pointing to ~ 1111111 0 e Recorder kJ[) Clock mm Friim1 lliMJ Applications Aldus PIF Editor the icon, then dragging with the mouse to the new group window; if you hold down the Ctrl key while you drag, you will leave the icon in its original group window and copy it to the new window. New program icons When you purchase a new application and you want it to run under Windows , you will probably want to add it to a Program Group. One of the options from the Program Manager file menu is Run - you are advised to run all Windows applications installation programs in this way as Windows will not only install the new program but also place the appropriate icon in the current Program Group for you. Supposing you want to place a Program Item for an existing application into a Program Group. First, activate the appropriate Program Group (such as My Apps) then select File New from the Program Manager menu bar. Since a group window is already open,Windows assumes you want to add a Fig.2: a set of related programs or program applications is called a "Program Group". This figure shows the programs normally available in the Accessories window. . The programs in the remaining Program Groups at the bottom of the screen can be displayed by doubleclicking on the icons. Program Item and so automatically selects it (Fig.5). After choosing OK, you then need to give Windows a short Description of the Program Item and tell it where to find the application and how to start it (Fig.6). Possibly the easiest method is to type the Description, press the Tab key to place the typihg bar on the Command Line and then choose the Browse button to locate the program's directory and the name of the file that loads it into memory. Once the application's (generally) .EXE file is located, choose OK then you can try to Change the icon that displays in the Program Group - although not all programs provide a special icon. Deleting icons & groups If you decide a Program Item is no longer needed to run a particular application in Windows (you may decide to group your favourites in My Apps for example), you can remove the item. Deleting the Program Item does not actually delete any of the program files - only the program icon New Program Object New <at> )ir.ciiir.ain.:iiro.up·: 0 Pro gr am ltem OK Cancel ~oup File: OK Fig.3: a new Program Group is created by first selecting File & then New from the Program Manager menu bar: Windows then displays this New Program Object dialog box. Select Program Group as shown, then click OK. I Cancel Fig.4: after you click OK in the previous dialog box, Windows displays the J>rogram Group Properties dialog box. This allows you to assign a name to the Program Group, while Windows fills in the Group File section for you. SEPTEMBER1991 67 Fig.5: to add a Program Item to an existing Program Group, you first activate the appropriate Program Group (such as Applications), then select File New from the Program Manager menu bar. Since a group window is already open, Windows assumes that you want to add a Program Item and so automatically selects it in the dialog box New Program Object New 0 OK Program Group <at>:rr'i:i\irii"mlfein"; Cancel is removed. Select the required icon then press Delete or choose File Delete from the Program Manager Menu Bar. Windows asks you to confirm the deletion. When you delete a Program Group, first minimise the group window then use the same procedure described above. If you want to remove all associated files, you need to use the File Manager to delete the files and remove the directories. Of course, you could also delete the files from the DOS prompt, but that defeats the purpose of the exercise, doesn't it? Swapping files One important way you can speed up Windows ' operation is to defragment your hard disc prior to installation with a utility such as the one included in Norton Utilities. There are not many applications performing such disc-intensive activities. Computers with 386 processors or higher can use virtual memory when in 386 enhanced mode. When Windows requires more memory it swaps information from memory to a swap file on the hard disc. This permanent or temporary hidden file reserves space on the hard disc for Windows to use for swapping. Windows automatically sets up a temporary swap file when running in 386 enhanced mode although a permanent swap file is desirable since it stays on disc and consists of contigu- . Command Line: OK Fig.6: this dialog box allows you to name the new Program Item & provide Windows with the necessary information to find & start the program ous disc blocks. The temporary swap file is created dynamically each time you start Windows. If you want a permanent swap file, Setup calculates the optimal size for the file based on the largest contiguous space it finds on the disc, thus it is advisable to defragment prior to installation. The permanent swap file dramatically increases the performance of the system because the file is stored in contiguous clusters, thus reducing the access time significantly. Should you decide to stay with the temporary swap file, regular defragmentation is a good idea so Windows can find sufficient space to create a large enough dynamic swap file . Temporary or permanent ? If you did not create a permanent swap file during Setup, a temporary swap file is created each time you start Windows. Windows determines the optimum size, but always leaves at least 512Kb free on the hard disc. You can set aside a portion of your SwaplileSwapfile has lound a suitable location for a swap lile on drive C: Largest ponible swap file size: Total lree dislt space: i llrowse... Cancel , Creilte 8194K bytes 16554K bs,tea Cilncel Reco-.ded awai, lile size: Fig.7: when Windows is running in 386 enhanced mode & gets low on memory, it swaps information from memory to a swap file on your hard disk. Although you can use a temporary swap file (Windows will create one each time it boots up), a permanent swap file will give noticeably improved performance. 68 SILICON CHIP hard disc for a permanent swap file after installation. As suggested above, make sure you defragment your hard disc first for the best results. Start Windows in real mode by typing WINIR at the DOS prompt. Make sure only the Program Manager is active, choose File Run, type swapfile then choose OK. Windows then displays the Swapfile dialog box (Fig. 7) which suggests the size of the largest swap file (contiguous disc space) that can be created on the current disc and the total amount of disc space available (contiguous and discontiguous). You can then make any necessary changes although as a general rule larger is better (make sure you leave enough disc space for normal operations) then choose Create. Exit from Windows then start Windows in 386 enhanced mode by typing WIN. When low on memory, Windows will now swap information from memory to the permanent swap file you just created. The swap file can be changed back to a temporary file by following the above procedure and choosing Delete from the Swapfile dialog box . Choosing disc drives If your computer has more thaJ.l one hard disc, for optimum performance place the swap file on the disc drive with the most available space. You can set the size and location of temporary swap files in the SYSTEM.IN! file as well as limit the disc space actually used. Next month, we look at the SYSTEM.IN!, WIN.IN! and PIF files, to see how you can further customise your window to the world. SC