Scott Mueller's Upgrading and Repairing PCs Forum

I have a Hitachi HTS726060M9AT00 drive from my old T42 laptop. It is a 60GB drive, 7200rpm, 5V 1.1A. I wanted to use it as an external drive, so I purchased a cheap 2.5" USB hard drive enclosure. I didn't think to check the HD power requirements beforehand, and USB only powers 500mA. The cable that came with the drive is a Y-shape cable. At first I wasn't sure why, but I think it's to give the drive access to two USB power lines, for a total of 1A. If If I plug only one in, the USB drive connects and disconnects in rapid succession, I'm guessing the drive not being able to spin up. If I plug in both ends into a USB port each, the drive remains as connected to the computer. What I want to know is, will the drive operate safely with 1A instead of 1.1A, or do I need to find something else to put my drive into? Thanks.

Edit: Nevermind. Running off of two USB ports, the hard drive remains connected *if* you don't attempt to access the drive. Attempting to access the drive will result in the same problems as with one USB port.

Check your enclosure, it probably has a small jack for a 5V AC adapter. If so, you can use more power hungry drives if you attach an adapter like this: http://www.shopaddonics.com/itemdesc.asp?ic=AAPAC5V

Some 2.5" enclosures used to come with adapters like that, others used Y-cables drawing power from 2 ports (data passes through only one of them), others only support drives that draw less than the 0.5A max available via a single USB port alone. Scott.

The enclosure makes no provision for AC power. It has a single USB port. I'm waiting for an RMA authorization to return it.

Edit: After a good deal of searching, I was able to find an AC powered 2.5inch PATA IDE hard drive enclosure. I'm going with the Tripp Lite U256-025-R, as seen at http://www.tripplite.com/products/produ ... =3171#spec. It includes an AC adapter, and I've been able to locate it online for $28.33, after $5.45 shipping and handling charges are added. Hopefully this will be more successful.

TrippLite hard drive enclosure arrived. Plus, powers drive, drive works, drive has red power light, green I/O light. Negatives, has eight tiny screws, not entirely clear from the instructions how to remove the casing halves (push side opposite of LEDs and ports away from center plastic frame, then push back, the case is positioned onto the port side by two positioning tabs), the hard drive does not sit fully horizontal without force which leads to a fracture in one of the four somewhat larger screw retaining points on the plastic frame when tightened, the eight tiny screws can be reluctant to fully screw back in (leading to scratches on aluminum case from slipping of included miniature screwdriver), top half of case doesn't sit completely flush against middle frame around the lengthwise edges, plastic frame has visible molding nub, frame extends beyond case on one lengthwise side indented on other lengthwise side, all screws are Phillips. Also, the USB port on the enclosure is a USB mini port, which could be a problem if you ever lose the cable and don't have any USB mini to USB cables laying around. I suppose about worth the $28, but definitely would not be worth the $49.99 MSRP.

Why do all PATA IDE to USB controllers appear to be 7.5 MIPS RISC CPUs?

I don't see that on mine. Scott.

Ok, the ATA to USB bridge controller in my enclosure is a Genesys Logic GL811E. The product page proudly lists the feature of an "embedded 7.5 MIPS RISC CPU" (http://genesyslogic.com/_en/product_01_1.php?id=20). The ATA to USB controller in the generic bus powered enclosure I am returning is an Alcor Micro AU6390. While the product page and databook do not mention MIPS (http://www.alcormicro.com/products_detail.php?main_id=6&p_id=48), the product page for the enclosure did say it was a 7.5 MIPS controller (http://censuspc.com/2.5-inch-Drive-Case-External-Enclosure-Ultra-Light-Aluminum-USB2.0-Smart-Drive-Enclosure.-SKU-HD-ESU25-pr-2656.html). I'm just wondering why 7.5 MIPS RISC seems so important, what it could be technically related to.

The enclosure mfrs. change internal boards (and chipsets) all the time, the Censuspc enclosure probably used to use the Genesys chip. Bottom line: I wouldn't put too much stock in the descriptions of some of these products, they may not in fact be accurate. Scott.