For my work, hobby and business, I need COMPUTING POWER! However, my needs are kinda picky and it took me many days to narrow down the 'ideal' hacking computer. This computer is for electronics hacking, and its also for business. Yeek! We got two of these, one as a personal workstation for all the web, graphics, programming, etc. And another one as the 'business' machine - for shipping, programming chips, etc.

Here is what my specifications were

1. Must have hardware/motherboard parallel port (printer port). Parallel ports are the pinkie toe of electronics hacking. Youd think they'd be gone by now but nooo, they're still there, hanging around and often necessary for using older software/hardware/schems. I use them a lot for talking to laser and label printers, CPLD/FPGA programmers, bitbanging all sorts of stuff, programming chips via PonyProg, etc.. USB-parallel converters aren't good enough due to the slowness from the USB layer. Hardware parallel ports are just damn handy!
2. Must have hardware/motherboard serial port (COM/Modem port). Two if you can. These are more common than parallel ports. You can use USB-serial ports for most things but sometimes you need the hardware speed of an onboard serial port especially if you're doing some funky bitbanging.
3. Should be small and quiet, we dont got a lot of room here at adafruit. And nothing is worse than fan noise.
4. Doesnt need hardcore video Not a lot of game playing around here, mostly working!
5. Processor type Can be Intel or AMD. Both are fine by us. Lately we've liked AMD a lot.
6. Lots of USB ports. Both on the outside and on the motherboard. Especially for the shipping computer theres just tons of stuff that needs to plug in - programmers, barcode scanners, scales, backup usb keys, Arduinos. You can also use hubs.
7. Whole machine for $500 Not including monitor, key/mouse, etc. We wanted it lean and clean.

Of course you should recycle what you can. In this case we had already recycled all our hard drives, CD rom drives, etc into other machines!

If you have some other suggestions, feel free to edit the wiki page. Thanks!

We like small desktop computers so we went with the Shuttle brand for a machine. We tend to build up machines ourselves since its often cheaper and better to do it this way. Looking through the AMD processor machines we found only a few with both serial and parallel (from our notes we wrote down SA76G2, SK22G2, SN21G5, SS21G, SS21T). For Intel machines you'll have to scour the Shuttle website.

It seemed like the SA76G2 was the model that was currently available, and not too expensive ($200 for motherboard/case/powersuppy). It comes with VGA, DVI, Ethernet, PS2, USB, 2 serial and a parallel port. This is great because we have onboard networking, video, and the ports we like.

For the processor we actually went with two options. One was the 'AMD Phenom II X4 810 2.6GHz 4 x 512KB L2 Cache 4MB L3 Cache Socket AM3' ($150, this was for my personal workstation) and the other was the 'AMD Sempron 140 Sargas 2.7GHz 1MB L2 Cache Socket AM3 45W' ($40, for the shipping/programming workstation). The shuttle cant power more than 95W so dont try to overdo it or you will get heat problems!

RAM is RAM in our opinion, you need 240-Pin DDR2 SDRAM PC2 6400. Since windows XP 32 cant recognize more than 4 G I just got 4G for the personal workstation and 2G for the shipping/programming workstation.

I rarely burn discs, so I just got a DVD-ROM for installing software. eh.

You can go with SATA or IDE. Since everything else here is IDE, we went with 160GB IDE drives.

None! The onboard video was perfect. Theres a video slot but we actually used that for the serial port bracket

Theres a single PCI card slot, which we used for a Wi-Fi card on the personal workstation. The business machine ended up connected to the ethernet drop so that was fine.

The computer has parallel on board, and theres a punchout on the case, but you'll need a PC8 parallel port adapter cable which has a 2mm header (NOT 0.1" IDC!)

The computer has 2 serial ports on board (COM1 and COM2). Unfortunately theres no punchout so you'll want a bracket. They're called "Serial Port Brackets" and come with a 10-pin IDC cable

Unfortunately, ours were miswired, and had 'alternating' pins soldered instead of 'incrementing' - you can fix this pretty quickly with some soldering.

If you're feeling adventurous, you can actually get two of these and a Keystone 9200-15 (double DB-9 bracket) and double up for both COM ports!

Personal machine: $200 + $150 + $80 + $30 + $50 + $20 + $10 + $20 = $560 - Nicer processor & 4 G RAM & wifi

Business machine: $200 + $40 + $40 + $30 + $50 + $10 + $20 = $390 - Cheap processor & 2 G RAM & no wifi

Which means that we met the budget of $500 (averaged together)

I rounded up because I didnt include shipping. The keyboards and monitors were recycled.

We've been happy with this set up, hopefully it will be useful for someone :)