GIF colour on PCs

My Web site, which only uses GIF pictures, looks fine when viewed on my Mac. However, Windows users say that some of the colours look odd when they view it using the same browser, Internet Explorer. Is this just PC/Mac incompatibility, or can I do something to correct this?

Ashley James

Although your GIF pictures can only use an indexed palette of 256 colours, unless you constrain your pictures to the 216 colours which make up the Web-safe palette, some users will see changed colours when they view your site. These 216 colours are the only ones guaranteed to be common to the major browsers running under Mac OS and Windows at all colour depths. For instance, if you use GIF images with a 256 grey-scale palette, only six of these greys appear in the Web-safe palette. All other greys will then be dithered by the viewer’s computer if it’s only able to display 256 colours, which could make a real mess of the picture.

You should also ensure you reference any colours defined in the HTML page using numeric notation ­ for example, #6600FF ­ rather than colour names, and once again using just the Web-safe palette. Continuous-tone JPEG images will show colour shifts for those browsing in just 256 colours (8-bit deep). You should check your pages on a range of different systems, including Macs and Windows set to 256 colours, before putting them online.

PowerBook modem

Since I upgraded my PowerBook G3 400/DVD to Mac OS 9, I keep losing the dial tone when using my internal modem. I can only restore the sound by opening the Sound control panel and checking the ‘Play sound through output device’ box. How can I fix this?

Edmund Wong

There are a number of problems which have been reported with PowerBooks running Mac OS 9 (and some earlier versions) and modem sounds. These are particularly common after sleeping, and Apple has attempted to rectify some of these issues in patches available from its Web site. However, the very best way of solving the problems is to upgrade to Mac OS 9.0.4, which contains all these fixes. The only problem areas which remain in this latest release of the Mac OS are in SCSI and USB, so if you’re using your PowerBook with complex peripheral set-ups, you should be prepared to downgrade to Mac OS 9, or possibly even 8.6.

HFS+

I have recently swapped my old LC II for a factory-refurbished Umax Pulsar 250, with 32Mb of RAM and a 2Gb hard disk. What’s the latest version of the Mac OS I can run on this machine? Do I have to be careful with HFS+?

Your old LC II had a 68030 processor, and was, as such, restricted to System 7. In contrast, your refurbished PowerPC model is based on a PowerPC 604e processor running at 250MHz, which is blisteringly fast by comparison. With just 32Mb of memory, you should be able to run Mac OS 8.6, but only if you turn on virtual memory. You may be better sticking to Mac OS 8.1 for the time being, although 8.6 would be a good choice if you can afford to upgrade your memory to 64Mb or more. Installing Mac OS 8 on clones isn’t as easy as with Apple’s own models, and you may find it helpful to browse around the Web to find tips and hints about the process before starting.

HFS+, or the Extended File System, shouldn’t cause you a problem with the Mac’s internal hard drive. However, if you’re going to use any external or removable disks with an older system as well (such as your LC II) you should format these as regular HFS.

Old Mac, Internet

I recently bought a second-hand LC 475 running System 7.1. I have so far been unable to get this online to the Internet, as none of the software I have tried runs on the machine. What software do I need?

Guy Hopkinson

You really need to start with a newer version of the Mac operating system. The LC 475 is based on a version of the Motorola 68040 processor, and is known as a ‘68K’ model, as opposed to current PowerPC models. You should be able to upgrade to System 7.5.5, and then obtain old 68K versions of email and browser software. A dealer or user group which maintains an archive of older applications and system software would be ideal, although all these tasks become easier once you’re connected to the Internet, of course.

Most recent Internet software is only available for PowerPC models running at least Mac OS 8, and so is incompatible with your machine.

(NOTE: old Internet system software is included on this CD. - Editor)

TCP/IP Ethernet

I connect my Power Mac 7600/180, Performa 630 and Windows notebook using a simple crossover cable (UTP/RJ45 Ethernet). How do I configure the TCP/IP software so that I can preserve the settings for my dial-up Internet connection?

Mike Bird

Open your TCP/IP control panel, and choose the Configurations item in the File menu to see the list of different settings available. If you duplicate your existing Internet settings, rename it to something logical like ‘Local’, and then adjust to suit your crossover connection with Windows, you should be able to switch back and forth easily. Alternatively, you could install the excellent IPNetRouter, which allows you to keep both local and dial-up TCP/IP connections active at the same time.

Formatted CV

I want to send my CV to a number of people who use a range of different computers and software. What’s the safest way of doing this? Is there any way of guaranteeing that they’ll view the file with the right fonts and layout?

Jim Meacock

Probably the most universal way of sending properly laid-out documents is to use Microsoft Word format, as that’s the most popular word processor on Mac and Windows machines. However, if a recipient doesn’t have Word, it can be difficult for them to convert your Word files into another word processor, so you might like to include ‘Rich Text Format’ (RTF) versions as well, as they can be read by most word processors. When saving native Word files, keep to the old MS-DOS 8.3 naming conventions, calling your file something like JMEACOCK.DOC, with the RTF version JMEACOCK.RTF.

However, as you may have discovered, most word processors will reformat files for the local system, substituting fonts, page size, and other printer settings. The only way around this problem is to use a platform-independent format, such as Adobe Acrobat PDF, which will be rendered as close to the original as possible, regardless of the system being used. The penalty is that end users may not have the free Adobe Acrobat reader application, so you should only send PDFs to those who know what to do with them.

Rescued Items

Sometimes, when I restart my Mac, the Wastebasket contains a folder called Rescued Items from the Hard Disk. There’s a Fax Browser document in there called Open Transfer, ranging in size from 1Mb to 6Mb. Why is this, and how can I get rid of it?

Dario Mitidieri

This occurs if an application has created temporary files, but has been unable to clean them up (by deleting them) before the restart. For instance, if Microsoft Word crashes, when you restart your computer, the temporary files in which Word was maintaining changes to the previously active document(s) will appear in a Rescued Items folder. You can then start up Word again, and it may be able to recover your work from those files.

In your case, it appears that these temporary files are originating from a fax application such as FAXstf: when you shut down or restart normally it should delete them, but because of an extension conflict, or the fact that you are using an old and incompatible version of the application, that’s not happening. Check you’re using the current version of your fax software, and turn off all non-essential extensions and control panels. Unless you need to recover the temporary files, you can get rid of them just by emptying the Trash or Wastebasket.

Backup solutions

I need to back up a network of G3s and G4s with 6Gb and 10Gb hard disks onto a removable medium. What’s the fastest and most reliable way of doing this?

Malcolm Webb

Although DVD-ROM is getting cheaper and more accessible, media costs and limited capacities mean that DAT tape (or the higher-capacity DLT variant or ADR) is still the best all-round solution. Look for a good SCSI tape system with Retrospect Remote software, and then develop a robust incremental backup schedule. Under that, you might perform a full backup of each machine once a week, with briefer incremental backups at the start or end of each working day. It’s easy to script this in Retrospect. Before relying on the system, check out your restore technique, too: there’s little point in backing up if you don’t know whether you can do anything with the backups.

Keyboard problem

When I try to start up my Power Mac 7100/80 AV, the keyboard lights continue to flash, but it doesn’t do anything more. I assume that some power management chip needs to be replaced. Which Mac repair companies would you suggest could fix this?

Mark Beaumont

By far the most likely cause of this is a dead PRAM backup battery. Macs contain a special memory chip, the Parameter RAM (PRAM), which stores settings such as sound volumes. This is kept intact, and the motherboard clock kept working, by a replaceable battery. When this goes flat, most Macs will no longer start up, and may mimic a serious motherboard problem.

You need a replacement lithium-thionyl-chloride 3.6 v half-AA size battery, available from all Mac dealers and many other outlets. If you replace it yourself, follow the instructions for opening your Mac’s case, and you can identify the battery carrier as a prominent caged component on the motherboard. Slip the cage off carefully, and make a note of the orientation of the old battery. Pop it out and insert the new one with the same orientation. Replace the cage, reassemble, and your Mac should then work fine once you have reset the date and time, and so on. If it doesn’t, you may need a new motherboard. Modern technology like this is rarely upgradable at the chip level, so in this rare circumstance a motherboard swap would be required.

Printer memory problems

I have finally treated myself to an iMac DV and a Lexmark Optra E310 laser printer. However, when printing, I find some large documents cause AppleWorks to run out of memory, and so have to be printed a few pages at a time. Also, the Optra’s standard 2Mb of memory appears to be insufficient to cope with some simple pages. How can I work out how much printer memory I really need?

John R Lee

There’s no simple way to work out how much memory a printer needs. With a non-PostScript printer, the printer driver generates each page as a rectangle of dots, at the required resolution and grey-scale depth, and then downloads that page image to the printer. For an area of, say, 9in x 6in at 600dpi, that page image would be about 20 million dots. If the page is black and white, that’s around 2.3Mb, explaining why you find 2Mb insufficient. While 4Mb should be adequate, you could overrun that if using colour or grey-scale images which result in the page image being sent using 8 bits per printed dot, instead of 2.3Mb you would need around 19Mb per page. However, data compression techniques in the printer as well as tackling the job in smaller chunks can alleviate this.

Predictions become more complex with printers which use a page description language such as PostScript. Then, instead of just dumping a page image to the printer, its driver generates a PostScript program to render the page on the printer’s PostScript interpreter.

Memory isn’t only needed to contain images (for example, from scanned images embedded in the page), but for the PostScript program, fonts, and so on. One way of wasting memory in a PostScript printer is to use TrueType rather than PostScript fonts, as the TrueType rendering engine also has to be downloaded to the printer’s memory.

Email file transfer

A colleague sent me a Microsoft Word document from a PC as an email enclosure. It arrived as a SimpleText document, but is clearly in binary rather than text format. If I try altering its creator and type to a Word document, it still can’t be opened, and no format option seems to work in the Open dialog box. How can I unscramble it?

Matt Hopkins

It’s possible that the Word document has been saved in Word 2000-native format, or has otherwise become unrecognisable by Word for Mac. The best solution is to open it from within Word itself, which should display the Convert File dialog box. In this dialog box, select the ‘Recover Text from Any File’ option, and Word will do its best to show you the text it can find within the binary file. You should also ask the sender to send the file again, using Word 97 format, appending the .DOC extension to the file name, and double-checking their attachment settings.