Introduction

More and more as time goes on we are seeing less of that old decrepit diskette drive. You know, the one, with disks that hold only 1.44Mb, which is not nearly enough. Added to that the disks were not all that reliable, it seemed like you played a game of roulette every time you stuck the disk in your machine. All of that has started to change. With USB pen drives starting to take some of the old diskettes market the future can only be better. USB pen drives offers sizes of up to 256MB; it makes you wonder why the diskette drive is still in use. They also offer more reliable data storage, the only problem is they can be quite a bit more expensive than a traditional diskette and they still can’t help you tote around all of your music collection. In steps the USB external hard drive. As technology progresses these enclosures are getting smaller and faster every day. With models on the market that use either a 2.5 inch laptop hard drive or the standard 3.5 inch hard drive you really can’t go wrong. You can realistically purchase one of these enclosures, install a hard drive you have laying around and you are ready to go.

The Enermax EHD-350-U2S is one such enclosure. Using a standard 3.5 inch device it lessens the setup cost of the unit, as well as making setup just a bit easier. Also using the USB 2.0 interface should technically give up to 480Mbps data transfer rates, which although under the as tested hard drives rate of 683Mbps it is still quite fast and very usable. Built from aluminum the unit is very attractive, and pretty sturdy. Also the ability to use any 3.5” device is a nice feature, so if you decide you want an external zip drive; you can slide it right in and there you go. Or if you want a little more space and use the device as an external hard drive you just install a hard drive and away you go. That sounds pretty good, so let’s take a look at the specifications.

Specifications

Taken directly from the Enermax site you can see the specifications of the enclosure.

Interface	USB2.0
Data Trans.Rate	480Mb/Sec.(USB to IDE)
DC Input	Adapter 27W
Material	AL6063
LED	Power blue/ Access red
Dimension	210.5*119.5*35mm(D*W*H)
Hot swap/Plug & Play	Yes
Color	Black, Silver
Application	3.5"IDE drive
OS	Windows 98/98SE/2000/ME/XP (Mac driver optional)

Packaging

The USB Enclosure came in a fairly attractive box, although a little beat up (thanks UPS). The front of the box includes a circle based background with the two models (colors) of the enclosure. Also written on the front of the box is the EHD-350’s device compatibility as well as some of the features. The rear of the box is pretty plan, basically just a white box with a blue border. Written in the white section is a full list of the features and specifications.

Technology

The actual enclosure is built upon the Genesys Logic GL811 controller chip. What this chip does is convert the PATA interface from your hard drive or other 3.5” device to a USB 2.0 interface. After doing a bit of research on this controller chip because of an issue I was and am still having with the enclosure (more on this later) I came up with an Adobe Acrobat file from the Genesys Logic website. This document is a full technological write-up on the chip so here are some of the more important sections.

• Complies with Universal Serial Bus specification rev. 2.0.
• Complies with ATA/ATAPI-6 specification rev 1.0 (PIO mode 0~4, DMA mode 0~2, UDMA mode 0~5).
• Complies with USB Storage Class specification ver.1.0. (Bulk only protocol)
• Operating system supported: Win XP/ 2000/ ME/ 98/ 98SE; Mac OS 9.X/ X.
• 64 / 512 bytes Data Payload for full / high speed Bulk Endpoint.
• Supports 8-bit/16-bit Standard PIO mode interface.
• Supports 16-bit multiword DMA mode and Ultra DMA mode interface (Ultra 33/ 66 / 100).
• Embedded USB 2.0 UTMI transceiver.
• Embedded 7.5 MIPS RISC CPU.
• ROM size: 4k words; RAM size: 128 bytes.
• Supports Power Down mode and USB suspend indicator.
• Supports USB 2.0 TEST mode features.
• 12MHz external clock to provide better EMI3.3V power input.
• 5V tolerance pad for IDE interface.
• Supports Wakeup ability.
• Available in 48-pin LQFP (9 mm * 9mm) package.

This truly is quite an interesting little chip. It is supposed to be a low cost highly compatible controller chip which from my research is fairly popular in USB enclosures. With support for PIO, DMA, and UDMA mode devices there are a lot of options for what this chip can control. It makes for a more universal enclosure, truly supporting any 3.5” device the uses the IDE interface.

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