Post by Bobbi
The Apple II+ arrived today and I have had a chance to play with it a bit. The good news is that it is working (much to my surprise.) It passes the Apple II+ Dealer Diagnostics with flying colours.
As I suspected, it is quite an early II+ serial A2S2-87816, mainboard dated 8028, and it has some quite interesting features. I snapped a few pics ...
Mainboard / baseplate pic: http://picpaste.com/IMG_20171012_163358-D9GkqlPn.jpg
1) Power Supply is silver, not gold, with a different shaped switch to usual. PSU serial is 10186.
2) Baseplate is painted grey on the inside as well as the outside.
3) Keyboard is Datanetics, with a separate encoder board. This seems to be the last 'pre-RFI' keyboard, according to Mike Willegal's page. Manufacture date is June 20 1980.
4) Main board is revision 7, pre-RFI. Date code 8028.
5) Language card is some no-name clone, it seems.
6) There is a strange mod to the 74LS195 at board location C2. It is mounted on a socket with long pins, about one inch above the board. Anyone have any idea why this was done?
7) There is a mystery card, with just a couple of small 74xx type devices and a 3.5mm jack.
1) The power switch is broken (fortunately failed in the On position)
2) Something seems to be wrong with the colour burst killer circuit. Seems the colour burst is always present so text mode is very fringe-y. Any ideas how to adjust this?