First things first: What is the headset/steer tube diameter?
Second: Is it threaded or threadless?

The answer to those 2 questions will tell you at a bare minimum whether or not a suitable candidate fork will fit.

The '90's were a strange time. 1 inch threaded, 1 & 1/8 threaded, 1 & 1/4 threaded, 1 inch threadless, or lastly 1 &1/8 threadless were all in flux as each manufacturer tried various innovations & standards to 1up eachother.

With threaded, the length of the steer tube is also a consideration. A little longer is ok because you can use a couple of spacers under the top nut. Too short...Well, you *may* get lucky and find a headset with a lower stack height. Most threaded headsets are between 40-50mm stack height, but as low as 30mm can be found. My guess is you would need at a minimum approximatly 200mm worth of steer tube.

With threadless it's much more simple. Just make sure the steer tube is long enough & you can hack off the extra or use spacers to adjust your stem height to basically anywhere you want so long as the stem clamp is within a few mm of the end of the steer tube.

What is your intended use for the bike? Any bike shop can order a replacement fork of the appropriate type. A used rigid fork from a co-op would also be inexpensive if you know what you are looking for.

I had a '90's Trek hardtail. I got lucky as it had a 1 & 1/8 threaded headset. So I dropped in a standard 1 & 1/8 threadless & converted to disc forks. It gave the bike a whole new life.

You may get lucky too, depending on the answer to the above 2 questions.