The A1500 was a special model only ever released by Commodore in the UK, and should not be confused with the Checkmate A1500. It is actually nothing more than a rebadged A2000 which came with two (880K) internal floppy drives instead of just one and was not sold with a hard drive. Infact on many A1500's you can peel off the A1500 sticker to reveal "A2000" underneath. The A1500 only ever used the newer A2000 motherboards which contained the ECS Chipset and Kickstart 2.04.
Please see the A2000