Re: Apple II 4k Memory Select Jumper Blocks for MB Rev. 0

["David Wilson" <mcs6502@gmail.com>]

spacealbum wrote:
> Does anybody know how the 4k Memory Select Jumper Bocks look like (if I
> am not mistaken only the Rev. 0 motherboard had the possibility to
> change various jumper block tytes. The later Rev. 1 boards had 4
> 16/16/16 blocks soldered to the board).

According to page 71 of the Apple ][ Reference Manual the pinout is:
           +-u--+
4K @ $0xxx |1 14| Front Row (C)
4K @ $1xxx |2 13| Middle Row (D)
4K @ $2xxx |3 12| Rear Row (E)
4K @ $3xxx |4 11| n/c
4K @ $4xxx |5 10| 16K @ $0000-3FFF
4K @ $5xxx |6  9| 16K @ $4000-7FFF
4K @ $8xxx |7  8| 16K @ $8000-BFFF
           +----+

I think that the following are possible configurations (I am assuming
the front row is populated first and that the labling of the blocks
follows that convention):
4K/4K/4K blocks would have 1-14, 2-13, 3-12
16K/4K/4K blocks would have 10-14,5-13,6-12
16K/16K/4K blocks would have 10-14,9-13,7-12
16K/16K/16K blocks would have 10-14,9-13,8-12