The 500 and 1000 had the same external expansion port, but it was on opposite sides of the machine, so some devices might look funny when installed. The A500 h

The 500 and 1000 had the same external expansion port, but it was on opposite sides of the machine, so some devices might look funny when installed. The A500 had also a trapdoor port under the keyboard to double the 512KB of RAM that was on the motherboard already. The A1000 had a clumsy daughterboard you'd have to install inside the case to double the onboard 256KB. Its Agnus controller also had a different packaging from the one on the A500, so it couldn't accomodate the newer Fat Agnus and Super Agnus (1MB or 2MB of audio/video RAM). Without expensive hacks, that is. The A1000 cost more to upgrade because the daughterboards had lower volume than on the A500. The external expansions cost more, for both computers, because they need a case, plus might need more logic. If 1MB was your target (and not just doubling what came with the machine), then on the A1000 the external port was the easiest. That, surprisingly enough, was also the solution with faster memory speeds. A silver lining. :-)