Later, Sony gained steam with new development kits for game developers and more PlayStations for consumers.
V3 has a substantially different internal structure from the subsequent revisions, featuring several interconnected printed circuit boards.
Only a few million users had obtained consoles by the end of 2000 due to manufacturing delays.
One of them includes the old EE and GS chips, and the other contains the newer unified EE+GS chip, otherwise being identical.
After an apparent manufacturing issue caused some initial slowdown in producing the new unit, Sony reportedly underestimated demand, caused in part by shortages between the time the old units were cleared out and the new units were ready.
V5 introduces minor internal changes and the only difference between V6 (sometimes called V5.1) and V5 is the orientation of the Power/Reset switch board connector, which was reversed to prevent the use of no-solder modchips.
It is backwards compatible with older PlayStation (PS1) games, allows for DVD Video playback, and will play PS2 games off of cheap CD-ROMs or higher-capacity DVD-ROMs.
Although Sony placed little emphasis on online gaming during its first year, all that changed because of the launch of the online-capable Xbox.
Developers also complained that it was difficult to develop for the system, with little in the way of reference material from Sony for its exotic architecture.
In September 2004 Sony unveiled the third major hardware revision (V12, model number SCPH-70000).
When it was released, the PS2 had many advanced features that were not present in other contemporary video game consoles, including its DVD capabilities and USB and IEEE 1394 expansion ports.
