J4-1 U5-39 U3-8 t1 (keys 78 (scrlk), 45 (caps lock) ), replaces D J4-2 U5-23 p22 (keys 81-84) J4-3 U5-22 p21 (keys 73-80) J4-4 U5-21 p20 (keys 65-72) J4-5 U5-34 p17 (keys 57-64) J4-6 U5-33 p16 (keys 49-56) J4-7 U5-32 p15 (keys 41-48) J4-8 U5-31 p14 (keys 33-30) J4-9 U5-30 p13 (keys 25-32) J4-10 U5-27 p10 (keys 17-24) J4-11 U5-28 p11 (keys 9-16) J4-12 U5-29 p12 (keys 1-8) J4-13 U5-12 U8-7 (o3) U4-3 (o1) db0 (keys 1+8n) J4-14 U5-13 U8-5 (o2) U4-5 (o2) db1 (keys 2+8n) J4-15 U5-14 U8-3 (o1) U4-7 (o3) db2 (keys 3+8n) J4-16 U5-15 U8-13 (o6) U4-9 (o4) db3 (keys 4+8n) J4-17 U5-16 U8-11 (o5) U4-11 (o5) db4 (keys 5+8n) J4-18 U5-17 U8-9 (o4) U4-13 (o6) db5 (keys 6+8n) J4-19 U5-18 U7-1 db6 (keys 7+8n) J4-20 U5-19 U7-2 db7 (keys 8+8n) J1-1 U1-9 OTHER END TO U4-12 (i5) TS ENABLE ON U5-36 (p25) J1-2 R8 100 OTHER END TO U4-14 (i6) J1-3 U1-13 OTHER END TO U4-2 (i1) J1-4 U1-12 OTHER END TO U4-4 (i2) J1-5 U1-10 OTHER END TO U4-10 (i4) J1-6 J1-7 J1-8 J1-9 U1-14 OTHER END TO U6-2 (oa OUTPUT) INPUT FROM U5-36 (p25) J1-10 U1-15 OTHER END TO U6-6 (oc OUTPUT) INPUT FROM U5-24 (p23) J1-11 U1-16 OTHER END TO U6-4 (ob OUTPUT) INPUT FROM U5-35 (p24) J1-12 GND J1-13 GND J1-14 +5 J1-15 U1-11 OTHER END TO U4-6 (i3) J2-1 U9-12 OTHER END TO U8-12 (i5) TS ENABLE ON U5-38 (p27) J2-2 U9-11 OTHER END TO U8-10 (i4) J2-3 U9-16 OTHER END TO U8-6 (i3) J2-4 U9-15 OTHER END TO U8-4 (i2) J2-5 U9-13 OTHER END TO U8-14 (i6) J2-6 J2-7 J2-8 J2-9 U9-10 OTHER END TO U6-12 (of OUTPUT) INPUT FROM U5-36 (p25) J2-10 R11 100 OTHER END TO U6-8 (od OUTPUT) INPUT FROM U5-24 (p23) J2-11 U9-9 OTHER END TO U6-10 (oe OUTPUT) INPUT FROM U5-35 (p24) J2-12 GND J2-13 GND J2-14 +5 J2-15 U9-14 OTHER END TO U8-2 (i1) J3-1 GND J3-2 GND J3-3 +10v THROUGH 3X51 OHM to area where battery would be, kb modified to not use battery J3-4 GND J3-5 KB OUT J3-6 GND U5-37 (p26) KB OUTPUT BUFFERED BY U2 U1 AB316B101 100 ISOLATED U2 74LS37 quad nand U3 MDP1401-223G 22K BUSSED U4 CD4503 NONINV TS BUF U5 8749H U6 CD4069 HEX INVERTER U7 MDP1401-223G 22K BUSSED U8 CD4503 NONINV TS BUF U9 AB316B101 100 ISOLATED Y1 6MHz 15 PIN INPUTS GO THROUGH 100 OHM RESISTORS AND ARE MULTIPLEXED CONTROLLED BY PINS 36 (p25) AND 38 (p27) OF 8749 output is open collector active low ttl. bits appear to be 144uSec async 6-pin kb cable appears to be wired straight-through 8042 in cpu box and kb powered whenever unit is plugged in when power switch is turned on, there is a burst of characters and U17-25 activates the power relay to turn the rest of the hardware on