Hard disk percussion
Hardware help from Windows 95
The Next chip up
Splitting power
The Pentium conspiracy
Q After returning from a vacation, I fired up my PC and found that the hard disk had gone south. The access light stays lit, but nothing happens. I tried booting from drive A: and accessing drive C:, but all I got was an error message. I've checked the hard disk settings in the BIOS and every cable connection. Is it time to admit defeat?
- Art Reynolds
A I have one last-ditch tactic. But first, a couple of warnings: If your system is under warranty, call tech support and ask if what I'm about to suggest will void the warranty-- and if the tech has any better suggestions specific to your PC. Second, my little trick may damage the hard disk, so it's really for people who want to get a hard disk running just long enough to retrieve data.
If I haven't scared you off, here's what to do. Turn off your PC and remove its cover. Hold a medium-size screwdriver by the stem and give the disk one good rap with the butt end - on top of the black metal casing, not on the sides (definitely not on the side with the circuit board). Don't whack it, but don't just give it a little tap, either. You may need to remove the hard disk to reach the top surface of the casing.
Now try turning on your PC again (reinstalling the hard disk if necessary). If you hear the familiar whine and clickety-clack of the hard disk starting, your experiment in percussion unstuck one of the read/write heads from the platter. When hard disks sit idle, this sticky situation may arise, especially if the PC is in a hot room or in direct sunlight, neither of which is recommended.
If your PC boots successfully, start by doing a complete backup. You should be able to replace the sticky hard disk for free if your PC is under warranty. If not, do a surface scan to see if any sector of the disk is damaged (ScanDisk, included with DOS and Windows 95, will do the trick). In most cases, your hard disk can work around those areas, although you'll lose data in the damaged sectors. Keep the PC running for a while. If you don't encounter trouble after a week, and you do daily backups, you can continue using that drive.
Q I'm a Windows 95 user, but the devices I want to install aren't Plug and Play boards. They're the old-fashioned kind with switches and jumpers. I've tried Microsoft Diagnostics to find a free IRQ I can assign a new device to, but it makes a lot of errors, and seems useless for determining free I/O addresses. Any suggestion for a good Win95 diagnostic utility?
-Prem Maleck
A You already have a great diagnostic utility. In the Win95 Control Panel, double-click the System icon, and click the Device Manager tab to see a tree with every device in your system that Win95 recognises (that is, every properly installed device). To make sure you're seeing the specific device models, click View devices by connections. Double-click any device, and a dialogueueue box will appear. Click the Resources tab to see the IRQ, I/O address, and so on, taken by that device.
Or double-click the Computer icon at the top of the tree. In the Computer Properties dialogueueue box, click the View Resources tab to see the IRQs, I/O addresses, DMA channels, and memory addresses your system uses. Set any new devices so that they don't step on the resources in use, and they'll run fine, provided you install a Win95 driver for each device via the Add New Hardware Wizard.
Q My 486DX2-66 is starting to show its weaknesses. My next upgrade must be a motherboard, and I'm considering jumping over the Pentium to a Pentium Pro board when prices settle down. Am I barking up the right tree?
-Stewart Weis
A You're right in thinking that if you own a DX2-66, swapping motherboards is better than upgrading your CPU. A Pentium OverDrive upgrade chip will provide too little boost for too much money. Ditto for a DX4-100.
The Pentium Pro may be the wrong tree, though. This chip is designed for 32-bit apps and actually runs 16-bit code slower than the Pentium. (This slowdown also occurs with Win95, since it contains enough 16-bit code to drag things down.) If you use Unix or Windows NT, a Pentium Pro might be worth considering, but even Intel admits that it won't be a mainstream product until 1997.
For now, a 133-MHz Pentium motherboard is your best bet. Get a quality board from a reputable vendor. See p118 of our February issue for a feature on upgrading your 486.
Q I have a 486 with two floppies, two hard drives, and a CD-ROM drive. Unfortunately, it has only four power connectors inside, so only four drives can run (I leave my 5¼in floppy unpowered until I need to use it). Is it safe to split one of the power cords so I can connect the fifth drive?
- Blair Hotchkies
A Yes, it's safe to split a power cord using a Y-connector, available for a few dollars at computer stores. Obviously, observe normal safety precautions. Chances are you'll never run all your drives at once, which could overburden your power supply. You could also buy a combination drive, which accepts both 5¼in and 3½in floppies.
Q I'd love to upgrade my 486DX2-66 to a Pentium, but not if I have to discard hundreds of dollars worth of 30-pin SIMMs and a VL bus graphics card and hard disk controller. All I see are Pentium motherboards with PCI buses and 72-pin SIMMs. Are 30-pin SIMMs and the VL bus incompatible with the Pentium, or is this a conspiracy forcing us to buy new components?
- David Moroder
A I enjoy a good conspiracy theory as much as the next guy, but here the explanation is simple. The VL bus runs at the same clock speed as the motherboard. In a 486, that never rises above 50MHz, the top speed of VL cards. Most Pentiums are 60 or 66MHz, too fast for VL cards.
When it comes to 30-pin versus 72-pin SIMMs, it all boils down to convenience and space. The Pentium has a 64-bit data bus, but 30-pin SIMMs are only 8 bits wide. That means adding 30-pin SIMMs eight at a time, whereas 72-pin SIMMs, which are 32 bits wide, can be added two at a time. No designer is going to give up space for 16 30-pin SIMM sockets. And if there were only eight 30-pin sockets, your next step up from 8Mb would be 32Mb (in 4Mb SIMMs), and you'd have to throw out the original eight 1Mb SIMMs.
Ready for more planned obsolescence? Expect to see 168-pin DIMMs (dual inline memory modules). They're 64 bits wide and will give Pentium users ultimate flexibility - you can add them one at a time, and they'll come in many capacities.
by Eric Knorr