Apple II 'Super II' motherboard from 1981

[nathan@visi.com (Nathan Mates)]

OK, I've got one of these prototype boards that eventually became the
//e.  Out of sheer habit, I made up a WWW page for it. Here's a copy
of that page, which has a master location of
http://www.visi.com/~nathan/a2/superii.html

--- Begin copy of WWW page:

                        Apple II 'Super II' motherboard
                                       
   Thanks to Dean Nichols for finding such a creation from the bowels of
   Apple and sending it down to me. First off, some facts about this: As
   identified by the silkscrened writing, this is a 'SUPER II (c) 1981'
   motherboard, made by Apple Computer, Inc, credited to Walt Broedner
   and John Macphee. Thus, it's a prototype board that never was fully
   produced.
   
   Next, I plopped this motherboard in a scanner at work and got 90% of
   it. (There's a little off to the right side that didn't fit; I'll see
   about a rescan and pasting that bit in.) This grayscale scan is
   available in 2 resolutions: small (337x480) and large (718x1024). They
   are at:
   
   Small: http://www.visi.com/~nathan/pix/superii_small.jpg
   Large: http://www.visi.com/~nathan/pix/superii.jpg
   
     _________________________________________________________________
                                      
Observations and technical comments

   At a first glance, this is almost a //e motherboard. It's got the 7
   slots plus extended slot out near the processor, a MMU and IOU unit to
   simplify most of the 74xx logic of the ][+ motherboard, a 9-pin game
   port next to dual cassette ports, and what looks like 64K of RAM on
   the board. However, it looks _too_ clean to be a //e motherboard--
   there's just too much wide open space. Also, all chips are socketed,
   but that's to be expected for a prototype.
   
   As I have no case, power supply and ROMs for a ][+ or //e, I have no
   way of powering this up right now; the rest of this is my educated
   guesses based on my knowledge of Apple II hardware, and my ability to
   follow traces on the motherboard. I don't have a 74xx handbook, so I
   can't conclusively identify all of them, but that's not too much of a
   problem for now.
   
   Starting with the processor, it's a 6502B, (2Mhz capable) identified
   with a 'S' logo and 8115/ SY6502B on it. The oscillator chip in the
   bottom right is rated at 14.31863 Mhz'; I'm not enough of an
   Electrical Engineer to be able to tell if it's running at 2Mhz or
   1Mhz.
   
   Below the processor are 2 mostly unlabeled ('S 8203 C10793' and 10792)
   chips that strongly remind me of the MMU and IOU chips on a //e. Note
   that one pin is pulled out on what I'd expect to be the MMU, the one
   on the right. Not sure why; it's probably debugging. The ROM sockets
   next to what I'd expect to be the MMU are empty, then a ROM with a
   silver sticker and 'KYBD 341 0132 B' written on the socket. Right of
   the 'KYBD' chip is an open socket, which I'd expect a keyboard decoder
   chip to fit, since there's a 26 pin connector labeled "keyboard" right
   above it. Left of that, labeled 'J16', is an 8-point solder pad that
   might be related to the //e's numeric keypad expansion port.
   
   With 8 chips in the bottom right of the motherboard, I'd expect this
   to be a 64K box. There's also a 'Chargen REV A 1.18.82 (c) Apple' in
   the bottom left. As mousetext didn't show up until the //c, I wouldn't
   expect this system to have such; not sure if it's got lowercase
   capabilities.
   
   Identified as 'Video Conn.', there's a 60-pin slot left of the
   processor. Not sure if this is the same number of pins as a //e's AUX
   slot or whether only a few cards were made for this one. There's only
   7 regular A2 slots in back, just like a //e and IIGS.
   
   The power connector looks like it's got solder points for a GS-style 6
   pin connector just next to it, but this capability probably was lost
   for a while in the //e. On the back plane, there's a 9-pin joystick
   connector, 2 cassette connectors, and a RCA video out. The 16-pin game
   connector is present on the motherboard, but not in the scan. [There's
   a white socketed 'NE558N 8128' an inch left of it; no idea why its
   socket is white.] Also, a set of 4 pins in a row in the back right;
   those might be for video connectons or something else.
   
   There'a a set of 6 easy solder/cut points in the mid-right; X1 and X5
   are connected, the rest are open.
   
     _________________________________________________________________
                                      
Less technical comments and blatant guesswork

   The obvious comment about this is: This is dated 1981. The //e came
   out in 1983. What took them so long??? Apple's longstanding enmity
   against the Apple II series is probably the reason-- they dropped
   almost all Apple II support when the Apple III was being worked on,
   and only after they recognized the magnitude of their failure did they
   come back.
   
   Another comment, thanks to Ian Schmidt, was "6502B in 1981? Almost
   sounds like an Apple III." No real way to tell that without booting it
   and playing around.
   
   Since this looks simpler than a //e motherboard, what got added to
   complicate it, and why? Not sure if the 'Video Conn' slot has the
   ability to connect up extra RAM, //e style or 'Super II' style. The
   extra RAM capabilities and double-*res are about it for the //e's
   additions over the ][+.
   
--- End copy from WWW page

Nathan Mates
--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
# What are the facts? Again and again and again-- what are the _facts_?
# Shun wishful thinking, avoid opinion, care not what the neighbors
# think-- what are the facts, and to how many decimal places?  -R.A. Heinlein