@Motormouth
Sorry I'm not sure about that. I can say that it would only work in the TOP slot of my A4000D, not at all in the other 3 slots, and not at all in my A4000T. I didn't test it with the A3000D or A3000T, once I got it running reliably I left it alone!
I do like the Janus software better than the Vortex. Some company also too the A2386SX, and removed the 386 chip and soldered a 486 in place. I think they sold a few like that but I have never seen one. Since the clip on upgrades work so well I never had the nerve to try this.