Need help finding the right computer. Please!

[whipsnade]

Hello,
I am new here. Can somebody please help me?

I have a plasma cam cutting table. I have no idea where to find the computer to run the darn thing.

I know I need a computer that has 2 'real' parallel ports, not USB adapted. Also I need 5 volt out-put, (standard bi-directional EPP or PS/2 mode), not 3.3 volt.

Can somebody please tell me where to find a computer or what they are using? I have called a few computer companies and the concept of 2 'real' parallel ports goes right over their heads.

Thanks for your help.
Whipsnade

[fyffe555]

You're not going to get a pc with 2 parallel ports off the shelf, and you probably wouldn't want to.

You can get parallel port adapters that will install into a PC's ISA or PCI slot. If you use one of these then if there's a crossed wire somewhere the card gets zapped but the PC motherboard doesn't. maybe a consideration in a more serious CNC use. You can get cards with multiple parallel ports too and two ports is common. For example do a google for 'PCI parallel port card' and you should find a bunch of single and double port cards. Prices start around $20 - $40..

Selecting the card depends upon whether your pc has ISA slots or not. Older pc's do, newer generally don't. ISA cards are sometimes cheaper, PCI card are more expensive and faster but that wouldn't affect a plasma machine. PCI cards may plug and play in windows easier if thats a consideration.

Other than that, what PC you get depends upon what Software you're running. If it's DOS based then just about any old thing would do, but you'd have to manually configure the cards. If it's windows then just get what the CNC software vendor recommends in speed and add the Parallel port card. If it's a dirty environment a surplus industrial PC might be worth a look if you got cash...

[High Seas]

whipsnade -
Don't pass up the bargin opportunities you can find at the Goodwill/Sally's/etc. You may even have a computer store nearby thats "recycling gear" to help you find a machine. You'll most likely need to add a card to get the 2nd port - but they're pretty cheap too.
For the 5 volts - you can "steal" that from the computer power supply 5 and 12 volts come off it to run stuff inside - just do a bit of "safe sleuthing". If the pc has a USB port, cut up a spare USB cable and check out the wires to find the 5 volts. Its low amperage, but works fine driving my Xylotex controller.
Hope there is some help - Jim

[sendkeys]

[whipsnade]

Fyffe555, High Seas & Sendkeys,
Thank you all for your suggestions. That's very helpful info and I will be checking into all of those options. I didn't know about the 'parallel port card' or even 'pricewatch.com'. Thanks again for your help!!!!!!
Whipsnade

[CNCPlastic]

Buy a Dell refurbished desktop for about $400, you can't build one as cheap as you can buy one of those refurbished pc's. I just built one from scratch and paid $500 and that did not include the Windows operating system.

Dell has one for $424 right now. You get 2.4gig cpu, 500mb ram, keyboard, mouse, Windows XP, thats a pretty good deal. Thats pretty much what I'm running. For a monitor shop your local used computer store, old monitors exist in huge numbers. I got a nice 17 inch sony trinitron for only $75.

I agree with others on the parallel port card. One thing for sure, people should test all the pins on the parallel port. My built in port (brand new Intel) was whacko, pin 13 (an input pin) had 5vdc and my Z stepper refused to work at all. Two other people I heard about had problems recently with theirs also. I installed a cheap made in china parallel port card (CompUSA) and it works perfectly.

http://outlet.us.dell.com/Dispatcher...rcDetail=offer

[High Seas]

Originally Posted by CNCPlastic One thing for sure, people should test all the pins on the parallel port. My built in port (brand new Intel) was whacko, pin 13 (an input pin) had 5vdc and my Z stepper refused to work at all. Two other people I heard about had problems recently with theirs also. I installed a cheap made in china parallel port card (CompUSA) and it works perfectly.

I agree 100% - You can save a lot of agrivation by knowing it works and the voltages are right - some drive at 3.3 volts not the 5 volts you need. I've been going to build one of these:
http://www.hut.fi/Misc/Electronics/c...el_output.html
but havent got a few other projects done yet. You can find the same thing off-the-shelf, but thought it would give me bragging rights if I built something that sorta looks electronic!
Jim

[whipsnade]

i just got two isa port cards (only about three bucks each!) from a supplier i found. now i need to find a pci to isa bus expansion system. i found a company called "contec" that has the adapter in question. i asked (email) for a supplier in the usa (they are in europe). does anyone know of another outfit??

thanks again to all!

[wms]

Here is one..but man is it pricy..not sure if this is what you are looking for..

http://www.cyberresearch.com/store/c...700_3228.2.htm

[whipsnade]

boy o boy you were not kidding! it is exactly what i was looking for. if i do go in this direction, i hope the isa card can provide a good epp 1.9 setup than the pci ps2 emulation i have now. for 600 bucks i am going to think a little on this. maybe an old computer is more in order!

thanks bud for the info!