Um8272

Floppy Disk Controller

Pinout

DIP40
         +---\/---+
   RESET | 1    40| Vcc
     *RD | 2    39| *RW/SEEK
     *WR | 3    38| LCT/DIR
     *CS | 4    37| FR/STP
      A0 | 5    36| HDL
     DB0 | 6    35| RDY
     DB1 | 7    34| WP/TS
     DB2 | 8    33| FLT/TRK0
     DB3 | 9    32| PS0
     DB4 |10    31| PS1
     DB5 |11    30| WDA
     DB6 |12    29| DS0
     DB7 |13    28| DS1
     DRQ |14    27| SEL
   *DACK |15    26| MFM
      TC |16    25| WE
     IDX |17    24| VCO
     INT |18    23| RD DATE
     CLK |19    22| RDW
     GND |20    21| WR CLK
         +--------+

Frequency

DIP40
Set reader to FREQ, put black probe to GND, red probe to 19 to measure CPU clock

Files

• 
  UM8272 Datasheet