James I dug up the info you wanted.    pva
To connect a 1200XL keyboard to a 800XL:
Remove and disgard U24 & U25 from 800XL motherboard.
Make the following connections:
1200XL K/B J8     (SIGNAL)     800XL PCB
     1              KR2         J8-9
     2              -           -
     3              KR1         U24-3
     4              K0          U24-11
     5              K1          U24-10
     6              K2          U24-9
     7              K3          U25-11
     8              K4          U25-10
     9              K5          U25-9
     10             RESET       J8-23
     11             S0          J8-20
     12             S1          J8-21
     13             S2          J8-22
     14             GROUND      U24-8
     15             +5V         U24-16

--- DLG Pro v1.105/PDQMail v2.60

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