68901 (DIP)
680x0 multi-function peripheral.
+-----+--+-----+
R//W |1 +--+ 48| /CE
RS0 |2 47| /DS
RS1 |3 46| /DTACK
RS2 |4 45| /IACK
RS3 |5 44| D7
RS4 |6 43| D6
TC |7 42| D5
SO |8 41| D4
SI |9 40| D3
RC |10 39| D2
VCC |11 38| D1
|12 37| D0
TAO |13 68901 36| GND
TBO |14 35| CLK
TCO |15 34| /IEI
TDO |16 33| /IEO
X1 |17 32| /IRQ
X0 |18 31| /RR
TAI |19 30| /TR
TBI |20 29| INT7
/RST |21 28| INT6
INT0 |22 27| INT5
INT1 |23 26| INT4
INT2 |24 25| INT3
+--------------+

68901 (PLCC)
680x0 multi-function peripheral.
PLCC52
+---------------+---------------+---------------+---------------+
| 8 TC | 21 | 34 /TR | 47 D6 |
| 9 SO | 22 TAI | 35 /RR | 48 D7 |
| 10 SI | 23 TBI | 36 /IRQ | 49 /IACK |
| 11 RC | 24 /RST | 37 /IEO | 50 /DTACK |
| 12 VCC | 25 INT0 | 38 /IEI | 51 /DS |
| 13 | 26 INT1 | 39 CLK | 52 /CE |
| 14 | 27 INT2 | 40 GND | 1 |
| 15 TAO | 28 INT3 | 41 D0 | 2 R//W |
| 16 TBO | 29 INT4 | 42 D1 | 3 RS0 |
| 17 TCO | 30 INT5 | 43 D2 | 4 RS1 |
| 18 TDO | 31 INT6 | 44 D3 | 5 RS2 |
| 19 X1 | 32 INT7 | 45 D4 | 6 RS3 |
| 20 X0 | 33 | 46 D5 | 7 RS4 |
+---------------+---------------+---------------+---------------+

146818
Real-time clock with 50 bytes RAM.
+-----+--+-----+
|1 +--+ 24| VCC
X1 |2 23| SQW
X2 |3 22|
AD0 |4 21| /RCLR
AD1 |5 20| VBAT
AD2 |6 146818 19| /INT
AD3 |7 18| /RST
AD4 |8 17| DS
AD5 |9 16| GND
AD6 |10 15| R//W
AD7 |11 14| AS
GND |12 13| /CE
+--------------+