you got that right joel. when i got my 90 i bought an "affordable" scanner that was supposed to do both systems but would not read OBD! on my car or someone else's. i had enough problems straightening out bubba's work that i wasn't going to add another headache. i have the mt2500 which i got off ebay and the otc was off ebay to as a factory refurbished unit. i have had no problem reading either system. eddie208902010-12-29 07:34:14

I haven'y had any problems with teh Vette yet that required a reader for anything. (Hope I don't.) So i haven't hooked it up there yet. Sorry.

I have a INNOVA 3140 that cost about $250.00 and does both OBD1 & 2. It works great on my 91 vette and also my 04 Chevy truck. I also used it on a 94 Ford  with no problem and it does do the right diagnosis. I did have a problem with the unit  the first year I had it with the screen going out but the manufacture did cover under their warranty which was expired by about a month. 

Snap On MT 2500 can do OBD I and can usually be found on e bay for less than 500$

I bought an Actron CP9145 in 2004 and it does a great job. It gives you the code name, and a brienf descrption of the code. You can also hook it up to your PC and download a report, just maek sure you install the Actron software. I also bought the OBDI connector (for my '84), only because the Actron has the ability to read live data (coolant temp, o2 activity, etc.....). Overall, I got A LOT of use from the Actron.