The supposed developer docs were uploaded to PDF-sharing website Scribd last night, and are believed to be the same documents leaked to various members of the press earlier this year.
The docs go into detail on Sony's plans for Neo and its "high-end" specifications, as previously reported, but also offer a closer look at timings, revealing that developers will be able to submit Neo-supported games from August.
It also reveals that a new 3.70 PS4 system software update is scheduled to be released this month, and that the first Neo testkits were released to certain developers in April-May, with worldwide availability following in June-July. Those testkits are to be returned to Sony at the "start of 2017", the docs add, prior to which "mass-produced units will be available". It caveats the timings, however, by saying that all dates are "internal targets, our best guess, not promises".
The document also details the way in which Neo will auto-detect the resolution of the player's TV and output an appropriate frame buffer. For example, the doc says that the Neo will "prepare a 1920x1080 display buffer when an HDTV is connected", or "prepare a 3840x2160 display buffer, usually using an efficient rendering technique such as 'checkerboard rendering' when a 4K TV is connected".
The frame rate of games supported by Neo must also meet or exceed the frame rate of it running on an original PS4, too, the doc suggests.
Sony confirmed that it was working on a new "high-end" PS4 - codenamed Neo - back in June. The console is expected to release later this year.