One of Bil Herd's finest designs. The C128 was already an excellent machine with its multiple CPUs, CP/M compatibility and C64 mode in hardware.
Yes, you could type GO64 while in BASIC and after answering affirmative to the 'really?' prompt you ended up in a 100% C64 environment. The Commodore 65
couldn't do that because it emulated the 64 in software. The 128D had a built-in 1571 floppy drive for reading GCR and MFM formats, and uses the same board as the stock 128 but obviously the
keyboard and power connectors were different because one was external and the other was internal. In the stock 128 they were the other way round.
This machine als has JiffyDOS on board for fast disk loading, but at the expense of tape support. Who needs tapes when your disks actually load at a reasonable speed now?
It's also in lovely condition as you can see, and works fine.