I have found again the original distributor/manufacturer site, where I bought (via e..y) the TL866II+ with the whole set of adapters: http://www.autoelectric.cn/en/tl866_main.html So the II+ can only handle +18Vpp, and the CS up to +21Vpp, so programming the old +25Vpp types (2708, 2716 and similar) are not supported. The whole discussion on eevblog can be found here: https://www.eevblog.com/forum/blog/eevblog-411-minipro-tl866-universal-programmer-review/ Frank