Every now and then I'm presented with an alert box telling me that the Program "Unknown" has terminated, because of an error Type 1. What is a Type 1 error and what can I do to avoid them? —Michael Chae, via the Internet
 
An Error Type 1 is a Bus error. In general they occur because an application has tried to write to or read from a memory address that is either not there or reserved for another purpose.
The error is commonly due to having insufficient memory assigned to the offending application, but can also be a sign of an extension conflict or even a bug in the software.
If the problem is being caused by insufficient memory, it is a simple matter to increase the amount of memory available to the troublesome software by increasing the Preferred Size figure in the Application's Get Info window.
If increasing the memory partition of the application doesn't work--and it may take several increases in allocation to overcome Type 1 errors--try restarting with extensions off and running the application again.
If the problem occurs only when you use the software in a particular way or do a particular series of actions, re-create these circumstances while running without extensions. If the error does not reappear, you can be confident the errors are being caused by an Extension or Control Panel conflict of some sort.
If the Type 1 errors occur for no apparent reason you will have to put the software through its paces in an attempt to get the error to reappear before being able to decide if the errors are being caused by errant INIT code.
If these first two options don't rid you of the errors it may well be a bug in the software. Before calling the software manufacturer, however, you might also want to take the time to rule out the (unlikely) possibility that the Bus errors are being caused by a dodgy SCSI chain. This is a rare cause of Type 1 errors but, if you can rule it out, it adds weight to your case when you contact the software company suggesting their software has a fatal bug. — BF.
 
  
I have a Performa 636CD with 20MB of RAM and I'm running Mac OS 7.5.3. Can I buy a speed booster in the form of a clip-on for the CPU and then later buy a PowerPC upgrade card? Will I still be able to use the clip-on speed booster? —David Sytsma, via the Internet
 
As far as I'm able to determine, there are no clip-on style clock chip accelerators that work on the 63x-series of computers from Apple. Apparently MicroMac were set to market and distribute such an accelerator being developed by a British company but nothing has come of that plan to date and there are no signs of the product appearing any time soon.
The PowerCard upgrades from DayStar Digital, which are the only PowerPC upgrade cards still available for your Performa, don't support clock chipping either. The PowerCard 100 does, however, provide your computer with a 100MHz 601 CPU and a 256Kb level 2 cache.
One further option is now open to you since Apple has finally started shipping the 5300/6300 Logic Board Upgrades. This upgrade makes it possible for you to upgrade your Performa to a full Power Macintosh running a 100MHz 603e CPU and a logic board which will run Copland (when Copland finally appears). — BF.
 
  
I've recently trashed a 63MB StuffIt Deluxe 3.5 archive, and now I need it back. I've used Norton Unerase to recover it from the Trash but am unable to unstuff the archive. StuffIt says the archive is corrupted. Norton reports that there is 0 kb in the resource fork and 63MB in the data fork. Is there any way to recover this archive, so it's usable? —Rob Gough, via the Internet
 
If StuffIt Deluxe is reporting the archive as corrupt, it almost certainly is corrupt I'm afraid. Moreover, it is likely the archive was corrupt before it was trashed.
Unfortunately, your chances of recovering the archive's contents are very low. If you have no backups of the archive and if it is critical that you get the information back I suspect your only real option is to contact DriveSavers, a California-based data recovery firm that specializes in getting data back when all hope is otherwise lost. According to email from one of their data recovery engineers the chances are slim but there is some hope that the data may be recoverable.
They strongly recommend, however, that you disconnect the drive which contains the corrupted archive from your SCSI chain so as to prevent any possibility of further damage to the file. If that isn't possible (e.g. if this drive is your only hard disk), at least don't write any data to this drive until DriveSavers has had a chance to attempt a recovery.
By the way, the fact that the file you recovered has no data in its resource fork is not likely to be the problem. Except for a required resource used by encrypted archives, StuffIt archives do not require resource forks.— BF.
 
"About this Macintosh…" is MacSense's monthly technical help and hints column. Got a question? Or a suggestion? We'd love to here it. Send your questions and helpful hints to BNForte@aol.com or bforte@adelaide.on.net.