No GPS and an INS that dumped often... I bet the GUN was trustworthy!
That machine looks like it was an absolute pleasure to destroy stuff with.
These were the old school beasts, the A-models. The new C-model conversions (which I never flew), are so much more technologically advanced, that they are essentially slow F-16s. That is, their advanced avionics, targeting pod systems, consent-to-release bombing systems, JDAM (GPS guided) munitions, and Laser Guided bombs, all make them able to employ very effectively from medium altitude, where the vast majority of Close Air Support is performed from.
The old A-models, all we had were dumb bombs, CBU, rockets. etc. We could carry LGBs, but they had to be laser marked by someone else......either another air platform or a ground platform, so it made no practical sense to carry them. But we weren't at all JDAM or other smart weapon capable. Due to that, we had to make up tactics in order to employ in certain ways. One example is so-called "Maverick Strafe". The AGM-65 Maverick was our only guided weapon at the time. And back then, the only way we could see at night was with NVGs (before that, we could only slew the IR Maverick around at night as a "poor man's FLIR"). So one way at night to strafe from somewhat long distances out, talking around 12,000+ ft slant ranges, was to bring up the Maverick missile and lock up a target with it. When the Maverick is on, a "wagon wheel" symbol appears in the HUD, showing where the missile is looking, as well as the target appearing in the Maverick TV screen in the cockpit. When locked onto the target, that is where the target is located. All this time, you're in a shallow, level dive towards the target from medium altitude. You then take the gun reticle which is also in the HUD, and maneuver the jet to superimpose that reticle over the Maverick wagon wheel. Fire a one second "check burst", and glance down into the TV screen to see via the Maverick's seeker head, where your gun rounds just impacted, adjust as necessary in the HUD, and fire again to hit the target. Problem with this method was that it was very workload intensive for a single pilot, and your attention is very much focused inside the cockpit, versus watching for threats outside. Too, you're on a shallow, wings level descent, which makes you a nice stable target for enemy AAA, were they to see you. But cool tactic nonetheless.