HP t5520 Eden Thin Client

Via Eden CPU @ 800mhz

128mb SDR RAM (fixed on board)

64mb Flash DOM (socket expandable)

100mbs integrated Ethernet

(4) USB 2.0 ports

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The CPU is a VIA Eden-ESP "Nehemiah" @ 800mhz with a TDP of 6watts. It has 64kb of L2 cache and a 133mhz FSB. The published release date was January 2004.

The stated power requirement for the whole unit is 12vdc @ 40w, but it is unlikely to ever draw more than 2 amps without the serial and parallel ports going full tilt.

The 128mb of ram is soldered to the mainboard and 16mb of that is unalterably dedicated to the video adapter. The remaining 112mb is obviously the main constraint on what can be done with these units.

The flash drive module (DOM) is pressed onto a 44pin miniature IDE connection and I've successfully used a 512mb module as a test and modules up to 2gb are readily available.

These flash DOMs are functionally equivalent to a hard drive except they wear out over time if there is a lot of overwriting, and they're slow - 30 megabyte/sec for reading and about half that for writing. Still, that's faster than the operational top speed of the integrated 100megabit/sec Ethernet adapter.

There are (4) USB 2.0 ports which will come in handy for mounting external CD/DVD drives, flash memory sticks, plus a USB mouse. There is a PS/2 socket for a keyboard, but none for a mouse.

The integrated VIA S3 Chrome 16mb graphics adapter is capable of 1280 x 1024, 32bit color at 85hz refresh, but the trick is to find an operating system with the required driver.VESA drivers work fine.

Also there is the integrated Realtek AC/97 16-bit CD quality audio input and output. Drivers are available for download from the Realtek web site.

A notable feature of the CPU is its full instruction conformance to the Intel P686 spec. Another feature for clustering these units is the integrated PXE Network Boot option in BIOS SetUp. This means the bulk of what would be stored in the DOM or on a USB bootstick can instead be kept on a server leaving space on a smaller DOM for read-only executables and libraries.

All of this in a 2 x 8 x 8 inch, 3 pound package. They're cute! And silent! Since they are convection cooled and don't have a hard drive, there's no fan noise, or thrashing sounds.

The natural and perfectly matched OS for this unit is Tiny Core Linux (TCL).

A lot of the units offered on eBay don't have power adapters for whatever reason, but most any power brick that can supply 30w of 12vdc to a 5.5mm/2.1mm power tip will work.

These units were in production between 12/05 and 6/06. I bought several new, still in the box, units with stands and power adapters in 2014 and units are still advertised on eBay.