detailed differences between EARLY PU 8 and LATE PU 8 mainboards - x-station/xstation-releases GitHub Wiki
Why the mainboard called “LATE”, and is there an “EARLY”?
Literally, yes! The PU-8 came in two major flavors (EARLY and LATE). You can check which mainboard you have by looking for these marks:
1. Mainboard labels
- EARLY mainboards are labeled PU-8-11/12
- LATE mainboards are labeled PU-8-21/22/23 or 41

2. The GPU and especially the VRAM area on the top side of the mainboard is different, see picture below

3. The Mechacon controller chip has different sizes, see picture below
