[chiph]

My 1040ST was an earlier one. Not sure if it was a Rev D motherboard but it did have the 1mb of RAM along the front, under the keyboard.

Atari wanted quite a lot of money for their external 3.5" floppy drive (so that you'd have two - one for your compiler and one for the source/target files). There was a magazine article about how to create a cable (the ST used a DIN connector for the 2nd floppy) so that a Radio Shack 3.5" drive could be used, and it worked fine.

The really annoying part was their hard drive expansion port was proprietary (19 pin D-Sub connector), and wasn't SCSI. That really limited the available choices for mass storage.

[bregma]

The proprietary port was actually SCSI in a non-standard format. There were readily-available conversion boards. I had a self-build external hard drive case with a (20 MB?) SCSI hard drive that let me boot up my ST to MiNT and run the GNU development tools. So close to Unix.