The 94 & 95 use the same pcm. Just different tune bin files for different cars & equipment.
You can get a aldl to usb port cable at the following link. For your 94, the 12 pin obd 1 cable is the one you want. OBD Diagnostics
I used to recommend Red Devil River Cables. But they left a member high & dry after sending him a defective cable. So don't buy that brand.
As for tuning programs, our member Steveo has one called "EEHack" it will change bin files and upload them to pcm. It's free to use. Look for posts by Steveo. In his sig at bottom of his posts, you will find a link to EEHack. I have not used the program, but it should be easy to use. Any questions, ask Steveo as he wrote the program.
EEHack should have scanning included with it for checking sensor data and reading codes.
Tunerpro rt will make changes to the bin file of pcm. But with this free program you need tunercat "winflash" to upload the new bin file to pcm. Winflash is 20 dollars at tunercat web site.
Tunercat's obd 1 tuning program is what I have. You can download a demo for free, but it doesn't have the correct definition file to read lt1 pcm. So you would have to spend 20 dollars on the $EE definition file needed to read 94-95 lt1 pcm.
A great scan program for free, was written by our member GaryDoug. It's called "scan9495" It was written for our 93-95 f-bodies. It scans for regular codes, ABS, & SIR codes. It does running sensor scans and will log data to a file for playback. It also tests engine & auto trans actuators. And it's free. www.mediafire.com/?0elo4c935uc5s
If you already have the obd 1 cable, just go to the link I will provide and download the newest version from the v-8 folder. To have program work, your pc needs dot net framework V 4.0 or newer. It's in a folder on same page as program. Or go to Microsoft site to download