Hi Tyler
Mammood’s idea is very practical, try this link www.kmitl.ac.th Dr. Sirichote have plans for a programmer for AT 89Cxx,it’s EZ2.0 and Bruno Marcio made single side PCB file in Protel format, works very nice, the Doc also has plans for SBC and PCB file too but in double sided format,if you have difficulty in making double side board then build the programmer first then wait for the single sided PCB I’m working on it.
If you have any question then email Doc Sirichote he’s very nice and helpful.
Best regards
Khanh