Tech Tips
My Mac Magazine #36, April ’98

Tech Tips continues on one issue partially covered last month, namely using the new Extended Format. I’ve personally had time to test it out on a variety of machines and would like to respond to several reader questions. Topics covered include what HFS+ (Extended Format) is, why to use it, how to implement it, and compatibility issues.

Let’s start by briefly covering what Extended Format is compared to the previously available options. The new formatting scheme allows your computer to store files on its hard disk and only consume their actual space. Previously, if your drive was larger than one gigabyte, smaller files would occupy larger chunks of the drive than they really needed to. A nice example is if you have a 4 gigabyte hard drive, then a Netscape cache file that was 4 kilobytes in size would actually occupy 64k of disk space. With Extended Format it will only take up the 4k of disk space.

There is really only one reason that you may want to use this new formatting scheme: increase the available disk space on your computer. A few things to consider in making the decision are the type of files you deal with, model of computer and the environment where the machine is used.

Here are a few scenarios to help make your decision:

  • Home user with a Power Macintosh, hard drive is 2 gigabytes. Extensive use of the Internet and word processing applications.Extended Format? Yes; the smaller files created with browser cache files and (typical) word processing files will use more disk space as opposed to with Standard Format.
  • Graphics/Desktop publishing professional, again a Power Macintosh but with a 4 gig drive. PageMaker and Photoshop are the applications of choice.Extended Format? No; the files normally associated with desktop publishing programs are several hundred kilobytes (heck, megs with Photoshop) and they would not greatly benefit from the new file system.
  • Office worker that uses several applications including database, Internet, word processing and Web site design running on a Quadra 840 with an external 2 gig hard drive.Extended Format? Yes, but only on the external drive (assuming the internal hard drive contains their System Folder); the amount of smaller files generated would justify converting the external drive. They shouldn’t format the internal drive since ‘040 based Macs cannot use virtual memory on an Extended Format drive (and Apple doesn’t recommend doing so-see below).

    Briefly, there are also technical limitations with the new format. You will need a hard disk that is larger than 1 gigabyte and need to be running Mac OS 8.1. I recommend that you have a PowerMac, although ‘040 based machines (Quadra class up) can use it. You can’t format the internal (boot) hard drive of an ‘040 Mac with it or more appropriately, you shouldn’t. Make sure you have a disk with MacOS 8.1 on it since booting with any other system will not let you see the contents of the HFS+ drive. A PowerBook that is connected (SCSI disk mode) to another computer can also have issues if the computer it’s connecting to is not running 8.1.

    There are basically 3 methods to convert your existing hard drives. I personally will back the contents off to another hard disk, format the drive with Apple’s Drive Setup 1.4 and tell it to make the drive Extended Format. In Drive Setup, when you click the Initialize button, there is an options button which leads to a new window with a pop menu where you can choose between extended and standard. Another method is to use PlusMaker from Alsoft that will convert your existing hard drive “on the fly” and not force you to reformat your drive. Alsoft can be found at:

    While I haven’t personally used PlusMaker, I’m hesitant to use it because:
    a: I have backup media available,

    b: completely formatting the drive helps to eliminate other problems and
    c: I have reservations about using such a product.

    I’ve heard very good reports from people who have used it, but highly recommend a backup before using it. The third option, which is very similar to my method, is to choose Erase Disk from the Finder’s Special menu. In the resulting dialog is an option to choose Extended or Standard. Keep in mind that it will wipe out the drive and require its contents to be restored.

    I’ve been running the new format on a variety of machines, but not on any non-PowerMacs. I can also testify that it increases the available disk space since one 8150 I converted to HFS+ saved 300 megs of disk space. There have been no issues associated with it and the applications I use and the programs my clients use. Last month’s column covered the primary utility programs that don’t work or have some problems with HFS+ which include Norton Utilities. One very important “compatibility” issue to keep in mind is that there is currently only one repair utility available and that is Apple’s Disk First Aid (version 8.1). It’s a free program but doesn’t recover data. I’m not aware of any other shipping utility that will work and this means that if your Extended Format drive crashes there is a very slim chance of recovering your information.

    MicroMat Technologies expects to release TechTool Pro 2 very soon and is claiming to work very well with the new format. They can be reached at:

    If you would like to read Apple’s technical documents regarding the new format I suggest doing a search for “Extended Format” at their Tech Info Web site:

    Real World Experience

    The system: Power Macintosh 6500.
    The problem: Fonts in Netscape and AOL display incorrectly.
    The solution: Replaced the corrupt font.
    The explanation: The problem revolved around the client noticing that she couldn’t read several dialog boxes in AOL and that in Netscape some pages had the same horrid look. Those of you who remember the days of bitmapped fonts and what happens when you scale them beyond their screen point size will understand what I’m referring to. The font displayed very jaggy. After isolating which font it was, I trashed the offending suitcase and replaced it from a known good system. By the way, Times was the culprit.

    Jeramey R. Valley (

    Websites mentioned:

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