OK, I'll ask...

[ko van Zeeland]

The first serie untill number 0000019 had only a tape drive the first revision
had full hight 180 KB single sided 5 1/4 inch floppy's

The second revision had the XT entry and two floppy drives and no more tape
connections.

I had to work with one of the first (XX003) took ages to load a program from
tape.

ko van Zeeland

 

[ko van Zeeland]

I think the Original IBM-PC (again not the later XT) may have had a

No, the first motherboard was 16K - 64K using up to 4 banks of 16K
chips. The B revision allowed 64K - 256K using 64K chips. I have both
models.

Tom lake

Correct!

ko van Zeelan