Networking and PowerBook Questions Answered
September 23rd, 1999

This week we've got quite a few interesting dilemmas to conquer -- File Syncronization, PowerBook hard drives, connecting a Mac to an NT network, and a very strange networking and file sharing issue. In addition to that, we have an answer about 2GB file sizes when capturing video. If you have your own question to ask, send it to [email protected], then read on!

Joseph DeGuzman writes, "Recently, I have been using a G3 Mac at work and it has an internal Zip. I used to work on files that are on the G3's HD but I need to sync these files to a Zip disk. When at home, I used this Zip disk to update/revise some of the files using a PC. I have no trouble syncronizing the Zip files into my PC as I am using the Win98's briefcase. Is there any Mac version of this briefcase so that I can just automatically sync the revised files into the G3's hard disk?"

Yes, there is a Mac utility included with the MacOS that will do this. On your version of the system, it's called "File Synchronization." It's located in your Control Panels folder, and it essentially lets you set two folders that reside just about anywhere (different disks, different servers, etc.) and you can synchronize the contents of those folders any way you choose. Check your Control Panels. If it's not there, then go and install it from your OS 8.5 CD-ROM.

Frederic Roy writes, "I have had a PowerBook G3 with 192 MB of RAM since March 99. In May, the hard disk started spinning on a regular basis, just about all the time, emitting a strong noise. I can spin it down from the on-screen control strip, but it spins again as soon as I do something, type or whatever.

Would you know of a setting that is incorrect, or is it a hardware problem that needs to be fixed by Apple?"

Frederic -- while there may, in fact, be a hardware problem, that's not necessarily the reason for your repeated spinups. The first thing to check would be the Energy Saver Control Panel and make sure that it's set to spin down the hard disk after some period of inactivity. Assuming that's all set correctly, lets examine WHY the disk might spin up. The most common answer to that question is "because the computer needs to read or write something from or to the disk." If you have some extension loaded that's constantly logging things to the hard drive, that's often a souce of this problem. Try going into your Extensions Manager and setting it to load MacOS 8.5 (or 8.6) Standard set and see if that fixes it. If it does, you know it's some errant extension getting in the way. If it doesn't, then it could be that you have Virtual Memory enabled. With that on, the hard disk will constantly be accessed to swap out sections of programs back and forth between the disk and physical RAM. With 192MB of RAM, you can probably turn off Virtual Memory and be OK, although there's been some discussion about performance problems on PowerBooks with VM off. For more info, see a previous column that touches on these subjects.

Joshua Ackerman writes, "I, along with my iMac, just moved to a boarding school in Connecticut. When I got there, I was distressed to find that in order to take advantage of the school's T1 Internet connection, I have to first log onto the NT network. I know that there probably isn't n easy way to do this, but this is my last chance... I may finally be forced to swtich to the PC."

Well, Joshua, you may be in luck! I am assuming that you can get an IP address assigned to you, but that your school's network is set up to only allow connections to the Internet from authenticated users. Short of them installing Services for Macintosh on the NT servers (not bloody likely!) there is but one solution: DAVE. No, not me.. :-) DAVE is a product from Thursby Systems that allows Mac computers to speak and act as a "Client for Microsoft Networks" on NT and 95/98-based LANs. They have a free trial available at their website, so you can check it out and see if it works!

Michael Kaplan writes, "I am having problems with networking my Blue & White G3-400mhz with another computer of the same model. I have a cable modem ([email protected]) plugged into the up-link port of a Linksys EtherFast 10/100 auto-sensing 8 port HUB. I have the computers plugged into ports one & two on the hub. The cable modem works fine on both computers as they both have their own assigned I.P. addresses.

My problem is that I can't transfer files of any kind between the two computers through the network. However, I can open applications on the shared disk of the other computer and use the apps fine. I can even do work in the application I opened on the other computer and save files from it to my computer, but I cannot transfer/copy files between the two computers. The two computers do not have a problem "seeing" each other on the network, they just can't copy a file from one computer to the other.. When I try to copy a file on the network, my cursor jerks slowly when I move it as if the computer is being totally bogged. The only way to cancel the copy is to disconnect the user from the network by doing so in the file sharing control panel. After the failed transfer, you can see an icon of the file you were just trying to transfer on the other computer, but no more than 1k of data is ever in the file.

Also, My network browser crashes if file sharing is turned on when I open it. note 1 :This problem occurs identically on both computers. note 2 :I have MAC OS 8.6 installed. note 3 :I have tried doing this off of a fresh installation of 8.6 with no other applications installed.

Apple suggested that there might be a problem with my hub and that I should purchase a UP-link cable and try to directly connect the computers without the hub. In my opinion the hub should not be the problem as the cable modem works fine and is connected to both computers through the hub. I also E-Mailed Linksys and asked them this question and they said "if the hub moves data it works, it's probably an extension conflict".

I just need to get you're opinion on this matter before I go and waste money on a up-link cable I don't need.

Well, Michael -- it could, in fact, be an issue with the hub. There are a couple of reasons I say this. First of all, I've seen hubs do very strange things. For example, I was once working on a mixed Novell and NT network (oh, the things we do for money!), and all the machines could see the Novell server, but NONE of them could see the NT machine. We had an extra hub there, plugged it in, and sure enough, everything came up just fine. Hubs are strange creatures, for sure. It's also possible that your Mac's are trying to connect as "full duplex" devices to this hub (you can check this in more recent versions of the Apple System Profiler, under Network Overview). If the hub doesn't fully support full duplex mode, you could have a problem. The cable modems won't typically use full duplex, and that can make for a weird mix on the network.

Additionally, your cable modem is most definitely connecting as a 10Base-T device, while your G3's are connecting as 100Base-T devices. The hub may be having some trouble operating at high speeds, and you're noticing it during file copies, where speed is optimized (or, at least traveling as best AppleTalk can!).

I would grab that crossover/uplink cable and give it a shot. It will at least answer your question for you.

Update to File Sizes

Last week, Joel Eisenberg wrote in to ask about his problems with capturing files larger than 2GB to his hard drive. Well, MANY people wrote in with answers about this, and Bruce Kurkowski and Lonnie Bear were kind enough to provide us with links to Apple's Tech Info Library. There are two articles there -- one about HFS and another about HFS+ -- that explain how both of these formats are limited to 2GB file sizes. Apparantly Adobe had released an update to Premier that somehow sidestepped this issue, but yanked it when it was causing file corruption.

That's it, folks! Send your questions in to [email protected], and enjoy!