With a need arising to carry the new RB 15F anti ship missile the onboard computer was inadequate. Instead of installing a computer in the missile pylon it was considered more effective to upgrade the onboard electronics.
Airplanes - Military - Static Display - Fighters
The extensive electronics upgrade of the old AJ/SF/SH in 1992 gave the ability to carry the Sidewinder on the outer wing pylons which had been unused as well as the ability to carry the newer RB 74. The AJS and AJSH also received the RB 15F anti-ship missile and BK 90 stand-off cluster bomb originally intended for the delayed JAS 39 Gripen