Logo SB180
SB180FX Headers SB180FX Jumpers
J1, SCSI Bus Header JP1, SCSI Termination Power
J2, Printer Port Header JP2, RXS/CKS/TXS Select
J3, Power Connector JP3, Hardware/Software Write Precompensation
J4, Memory Expansion Header JP4, LCAS Select
J5, Memory Expansion Header JP5, EPROM Size Select
J6, Console Serial Port Header JP6, Write Precompensation
J7, Modem Serial Port Header *
J8, 8" Floppy Disk Interface Header *
J9, XBUS I/O Expansion Header *
J10, 8255 PIA I/O Header *
J11, 3.5"/5.25" Floppy Disk Interface Header *
J12, External Reset & Power LED *

J1, SCSI Bus Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                    GND     1   2     B0
                    GND     3   4     B1
                    GND     5   6     B2
                    GND     7   8     B3
                    GND     9  10     B4
                    GND     11 12     B5
                    GND     13 14     B6
                    GND     15 16     B7
                    GND     17 18     PARITY
                    GND     19 20     nc
                    GND     21 22     nc
                    GND     23 24     nc
      TERMINATION POWER     25 26     TERMINATION POWER
                    GND     27 28     nc
                    GND     29 30     nc
                    GND     31 32     -ATN
                    GND     33 34     nc
                    GND     35 36     -BUSY
                    GND     37 38     -ACK
                    GND     39 40     -RESET
                    GND     41 42     -MSG
                    GND     43 44     -SEL
                    GND     45 46     CTL/-DATA
                    GND     47 48     -REQ
                    GND     49 50     IN/-OUT
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J2, Printer Port Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                -STROBE     1   2     GND
                     D0     3   4     nc
                     D1     5   6     nc
                     D2     7   8     nc
                     D3     9  10     nc
                     D4     11 12     nc
                     D5     13 14     nc
                     D6     15 16     nc
                     D7     17 18     nc
                   -ACK     19 20     nc

             nc = no connection (pin is floating)
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J3, Power Connector
The power connector is usually the same connector found on 3.5" floppy disk drives, making it convenient to use standard PC power supplies with this board.
            DESCRIPTION     PIN #
           ------------     -----
                 +12VDC     1
                    GND     2
                    GND     3
                  +5VDC     4
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J4, Memory Expansion Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                    GND     1   2     -RAS (-BR)
                    GND     3   4     -WR  (-BW)
                    GND     5   6     -LO CAS (-BL)
                    GND     7   8     Mx A0
                    GND     9  10     Mx A1
                    GND     11 12     Mx A2
                    GND     13 14     Mx A3
                    GND     15 16     Mx A4
                    GND     17 18     Mx A5
                    GND     19 20     Mx A6
                    GND     21 22     Mx A7
                    GND     23 24     Mx A8
                    GND     25 26     Mx A9
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J5, Memory Expansion Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                  +5VDC     1   2     STB
                  +5VDC     3   4     Bk A0
                  +5VDC     5   6     Bk A1
                  +5VDC     7   8     CLK (PHI)
                  +5VDC     9  10     -REFRESH
                  Bk A2     11 12     D0
                  Bk A3     13 14     D1
                    GND     15 16     D2
                    GND     17 18     D3
                    GND     19 20     D4
                    GND     21 22     D5
                    GND     23 24     D6
                    GND     25 26     D7
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J6, Console Serial Port Header
NOTE: This header's pins are numbered so that a ribbon-cable pin-header connector can be used on one end of a ribbon cable and a ribbon-cable DB25 can be used on the other end of the cable, and the DB25 pin numbers will be 'preserved' correctly on the J3 pin header.
Note that pins 5, 6, and 8 are driven "true".
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                     nc     1  14     nc
                    RxD     2  15     nc
                    TxD     3  16     nc
                    RTS     4  17     nc
                    CTS     5  18     nc
                    DTR     6  19     nc
                    GND     7  20     nc
                    DCD     8  21     nc
                     nc     9  22     nc
                     nc     10 23     nc

             nc = no connection (pin is floating)
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J7, Modem Serial Port Header
NOTE: This header's pins are numbered so that a ribbon-cable pin-header connector can be used on one end of a ribbon cable and a ribbon-cable DB25 can be used on the other end of the cable, and the DB25 pin numbers will be 'preserved' correctly on the J4 pin header.
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                     nc     1  14     DTR
                    TxD     2  15     nc
                    RxD     3  16     nc
                    RTS     4  17     nc
                    CTS     5  18     nc
                     nc     6  19     nc
                    GND     7  20     DTR
                    DCD     8  21     nc
                     nc     9  22     nc
                     nc     10 23     nc

             nc = no connection (pin is floating)
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J8, 8" Floppy Disk Interface Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                    GND     1   2     -LOW CURRENT
                    GND     3   4     -FAULT RESET (not used)
                    GND     5   6     -FAULT       (not used)
                    GND     7   8     -MOTOR ON 2  (not used)
                    GND     9  10     -TWO SIDED
                    GND     11 12     -MOTOR ON 1  (not used)
                    GND     13 14     SIDE SELECT (0/-1)
                    GND     15 16     -MOTOR ON 0  (not used)
                    GND     17 18     -HEAD LOAD 0
                    GND     19 20     -INDEX
                    GND     21 22     -READY
                    GND     23 24     -HEAD LOAD 1 (not used)
                    GND     25 26     -DRIVE SELECT 0
                    GND     27 28     -DRIVE SELECT 1
                    GND     29 30     -DRIVE SELECT 2
                    GND     31 32     -DRIVE SELECT 3
                    GND     33 34     DIRECTION
                    GND     35 36     -STEP
                    GND     37 38     -WRITE DATA
                    GND     39 40     -WRITE GATE
                    GND     41 42     -TRACK 0
                    GND     43 44     -WRITE PROTECT
                    GND     45 46     -READ DATA
                    GND     47 48     -HEAD LOAD 2 (not used)
                    GND     49 50     -HEAD LOAD 3 (not used)
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J9, XBUS I/O Expansion Header
This header is the same as J5 on the SB180, with the addition of the address signals A5, A6, and A7.
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
              +5VDC PWR     1   2     +5VDC PWR
                    GND     3   4     GND
                    -RD     5   6     PHI
                    -WR     7   8     -RESET
                      E     9  10     -LIR
                   -NMI     11 12     -EXP SEL (E0-FF)
                  -WAIT     13 14     A7
                  -INT0     15 16     -HALT
                     ST     17 18     A5
                     A0     19 20     A1
                 -TEND0     21 22     A2
                     A3     23 24     A4
                 -DREQ0     25 26     -I/O ENABLE
                   8MHZ     27 28     RESET
                     D7     29 30     D6
                     D5     31 32     D3
                     D4     33 34     D2
                     D1     35 36     D0
                    GND     37 38     GND
                     nc     39 40     A6

             nc = no connection (pin is floating)
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J10, 8255 PIA I/O Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                    GND     1   2     GND
                    PB3     3   4     PB4
                    PB2     5   6     PB5
                    PB1     7   8     PB6
                    PB0     9  10     PB7
                    PC7     11 12     PA7
                    PC6     13 14     PA6
                    PC5     15 16     PA5
                    PC4     17 18     PA4
                    PC3     19 20     PA3
                    PC2     21 22     PA2
                    PC1     23 24     PA1
                    PC0     25 26     PA0
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J11, 3.5"/5.25" Floppy Disk Interface Header
            DESCRIPTION     PIN #     DESCRIPTION
           ------------     -----     ------------
                    GND     1   2     OPTION (?)
                    GND     3   4     HEAD LOAD/-IN USE
                    GND     5   6     -DRIVE SELECT 3
                    GND     7   8     -INDEX
                    GND     9  10     -DRIVE SELECT 0
                    GND     11 12     -DRIVE SELECT 1
                    GND     13 14     -DRIVE SELECT 2
                    GND     15 16     -MOTOR ON
                    GND     17 18     DIRECTION
                    GND     19 20     -STEP
                    GND     21 22     -WRITE DATA
                    GND     23 24     -WRITE GATE
                    GND     25 26     -TRACK 0
                    GND     27 28     -WRITE PROTECT
                    GND     29 30     -READ DATA
                    GND     31 32     -SIDE SELECT (0/-1)
                    GND     33 34     -READY
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J12, External Reset & Power LED
            DESCRIPTION     PIN #
           ------------     -----
                  +5VDC     1
+5, through 470 pull-up     2
                 -RESET     3
                    GND     4
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JP1, SCSI Termination Power
This jumper connects +5VDC to either the on-board SCSI termination resistor packs (the default), or to the SCSI bus connector J1 pins 25 and 26.
JP1 Image


          Yellow: +5VDC to on-board SCSI bus termination (default)

             Red: +5VDC to SCSI bus J5 pins 25 and 26



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JP2, RXS/CKS/TXS Select
This jumper
JP2 Image


          Yellow: (default)

             Red: 



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JP3, Hardware/Software Write Precompensation
This jumper determines whether the write precompensation signal to the FDC is software controlled, or hardware controlled (controlled by the FDC -R/W/SEEK and LCT/DIR signals, the default). See also JP6.
This jumper also enables/disables drive size/speed control for J11 3.5"/5.25" floppy header pin 2. This is enabled by default.
JP3 Image


          Yellow: Hardware write precompensation, drive size/speed enabled (default)

             Red: Software write precompensation



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JP4, LCAS Select
This jumper determines the source for the LCAS DRAM signal. The default source is U48 pin 11, derived from RAM/ROM and A18. The alternate source is U45 pin 6, derived from -REFRESH and A18.
JP4 Image


          Yellow: LCAS derived from RAM/ROM/A18 (default)

             Red: LCAS derived from -REFRESH/A18



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JP5, EPROM Size Select
This jumper connects pin 27 (A14) of the EPROM socket to either a 4.7k pull-up (the default), or to address line A14. I also connects pin 1 (-PGM) to either +5VDC (the default), or to address line A15.
JP5 Image


          Yellow: for EPROM pins 1 and 27 to +5VDC (default)

             Red: for EPROM pin 1 to A14

            Blue: for EPROM pin 27 to A15

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JP6, Write Precompensation
This jumper determines whether the write precompensation signal to the FDC is off (tied to GND, the default), or hardware/software controlled (controlled by JP3).
JP6 Image


          Yellow: no write precompensation (default)

             Red: Hardware/software controlled write precompensation, as determined by JP3.



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