Macintosh Classic II
The Classic was the replacement for the aging Plus. Introduced in the end of 1990, it was the first sub $1000 Mac, priced at $999. It brought along the same 68000 processor, 1 MB of RAM standard (which could be expanded to 4 MB with a specific memory card), but in a redefined (more rounded) case, ADB and the possibility of an internal SCSI HD (although that latter configuration was more pricier).
One curious thing about the Classic (and Classic II) was the inclusion of a full System 6 installation in its ROM. One can boot from the internal ROM by pressing Command+Option+X+O at startup (hence the codename "XO"). Unfortunately, I haven't been able to test this in both my Classic II units because they are both nonoperational - they present a bar-like pattern at startup, no chime, and turning them off and on again simply produces the same result. From what I have investigated, this might be related to capacitors leaking into the motherboard and interrupting some of the printed tracks. One solution is remove the motherboard and wash it throughly in a dishwasher (obviously, you have to let it dry for a very long time before applying current to it again!). I haven't tried that yet, because I still haven't got the tools to open the case...
Since I was not able to boot them, I still don't know the exact specifications of both units. Once I get hold of the proper tools, I'll update this information.