KAYPRO  II    I/O PORTS            11 11 83


PORT#                           USE                     CONNECTOR
-------------------------------------------------------------------
04  SIO A DATA                 RS-232                  (J4) DB-25
05  SIO B DATA                 KEYBOARD                (J3) phone type
06  SIO A CONTROL              RS-232                  (J4) DB-25
     01     bit 0-receive character available
     02     bit 1-interupt pending (Channel A only)
     04     bit 2-transmit buffer empty
     08    *bit 3-DCD -Data Carrier Detect
     10    *bit 4-sync/hunt
     20    *bit 5-CTS -Clear to Send
     40    *bit 6-transmit underrun/eom
     80    *bit 7-break/abort
           *"External/status interrupt" mode

07  SIO B CONTROL              KEYBOARD                (J3) phone type
08  GP/PIO A DATA              CENTRONICS              (J2) DB-36
09  GP/PIO A CONTROL           CENTRONICS              (J2) DB-36
0A  GP/PIO B DATA              NOT USED                 E7-E14
0B  GP/PIO B CONTROL           NOT USED                 E7-E14
......................................................................
DISK DRIVE CONTROLLER PORTS                U82-1793/7
10  IN: STATUS; OUT: COMMAND
11  IN/OUT: TRACK
12  IN/OUT: SECTOR
13  IN/OUT: DATA
......................................................................
1C  SYS/PIO A DATA             SYSTEM BIT PORT
1D  SYS/PIO A CONTROL
     01  bit 0-disk drive A select(active low)
     02  bit 1-disk drive B select(active low)
     04  bit 2-not used  (E40 solder pad)
     08  bit 3-centronics ready flag( i.e. not busy)
     10  bit 4-centronics data strobe(active low)
     20  bit 5-double density enable(active low) E38 solder pad
     40  bit 6-disk drive motors on (active low)
     80  bit 7-memory bank select
1E  SYS/PIO B DATA           NOT USED(8 bits)       E28-E35 solder pads
1F  SYS/PIO B CONTROL        NOT USED(8 bits)       E28-E35 solder pads
.......................................................................
DB-25 PINOUT       MNEMONIC       DESCRIPTION

1                  Grnd           FRAME GROUND
                                  (tied to signal and ground bus)
2                  TxD            TRANSMIT DATA
3                  RxD            RECEIVE DATA
4                  RTS            REQUEST TO SEND
5                  CTS            CLEAR TO SEND
6                  DSR            DATA SET READY
                                  (tied to 5 volts at KPII)
7                                 SIGNAL GROUND
8                  DCD            DATA CARRIER DETECT
9                  DTR            DATA TERMINAL READY