<< What?!! I don't understand how you can use a 486 to emulate a part for a Direct-TV system. Tell me how that works... >>
I am not going to post any instructions, but here's what I know about the process and hardware requirements. This is for informational purposes only and my intent is to discourage DTV piracy because (a) it is illegal and (b) it is cheaper to be a legal subscriber!!!
Someone wrote a DOS program that emulates part of the DirecTV access card (the old "H" card...not the new Hu cards). You still have to have a valid working H card, a smartcard reader (one of the COM ports) and an "emulator" RS232 board that plugs in the slot on your receiver (the other COM port). The program runs off a bootable DOS floppy and requires no hard drive or memory (except base mem). This setup will cost about $500 or so. The most difficult part of an emulator setup is that you must have the image file from a subscribed working H card. This is the hard part. They're not readily publicly available and DTV has converted about 2/3 of the subs over to the new Hu card.
An emulator setup is pretty much bulletproof as the H card is never in the datastream and cannot be written to. The alternative hack was to actually write a script to the access card, but this method has been rendered useless by DTV in recent months (do a deja search on "Black Sunday".
Again, I'm not giving any instructions, just trying to describe why someone would want this cheap 486 PC. Do not steal DTV...it makes it more expensive for us subscribers!!!