
ACCELERATED COMPUTER TECHNOLOGY, INC.

UNIVERSAL FLOPPY DISK CONTROLLER

Card Type               Floppy drive controller
Chip Set                Unidentified
Maximum Onboard Memory  None
I/O Options             Floppy drive interface (3)
Data Bus                8-bit ISA
Floppy drives supported Four 360KB or 720KB drives

                        Four 360KB, 720KB, 1.2MB, or 1.44MB drives

[Image]

                                CONNECTIONS

         Function           Label            Function             Label

  34-pin floppy drive         J1       34-pin floppy drive         J3
  interface                            interface

  37-pin floppy drive         J2
  interface

  Note: J1 is the connector for drives A: and B:, either J2 or J3 can be
  used to connect drives C: and D:.

                        USER CONFIGURABLE SETTINGS

                   Function                      Label        Position

      Step rate of floppy drive A is 3 Ms        SW1/1           On

      Step rate of floppy drive A is 6 Ms        SW1/1          Off

      Step rate of floppy drive B is 3 Ms        SW1/5           On

      Step rate of floppy drive B is 6 Ms        SW1/5          Off

      Step rate of floppy drive C is 3 Ms        SW2/1           On

      Step rate of floppy drive C is 6 Ms        SW2/1          Off

      Step rate of floppy drive D is 3 Ms        SW2/5           On

      Step rate of floppy drive D is 6 Ms        SW2/5          Off

      Drive order will be MODE 1(see             SW3/1          Off
      MISCELLANEOUS TECHNICAL NOTE 2)

      Drive order will be MODE 2 (see            SW3/1           On
      MISCELLANEOUS TECHNICAL NOTE 2)

      UFDC is the primary floppy drive           SW3/2          Off
      controller

      UFDC is the secondary floppy drive         SW3/2           On
      controller

     EPROM enabled                              SW3/3           On

      EPROM disabled                             SW3/3          Off

     TYPE 1 or 2 drives (see MISCELLANEOUS       W1         Pins 1 & 2
      TECHNICAL NOTE 1)                                        closed

      TYPE 2 or 3 drives (see MISCELLANEOUS       W1         Pins 2 & 3
      TECHNICAL NOTE 1)                                        closed

     Pin 2 on the interface cable is an          W2         Pins 1 & 2
      output signal                                            closed

      Pin 2 on the interface cable is an          W2         Pins 2 & 3
      input signal (TYPE 2 drives only)                        closed

                 FLOPPY DRIVE A CONFIGURATION

      Type           SW1/2           SW1/3          SW1/4

  360KB (5.25)        On              On             Off

  1.2MB (5.25)        On              Off             On

  720KB (3.5)         On              Off            Off

  1.44MB (3.5)        Off             On              On

      None            On              On              On

                 FLOPPY DRIVE B CONFIGURATION

      Type           SW1/6           SW1/7          SW1/8

  360KB (5.25)        On              On             Off

  1.2MB (5.25)        On              Off             On

  720KB (3.5)         On              Off            Off

  1.44MB (3.5)        Off             On              On

      None            On              On              On

                 FLOPPY DRIVE C CONFIGURATION

      Type           SW2/2           SW2/3          SW2/4

  360KB (5.25)        On              On             Off

  1.2MB (5.25)        On              Off             On

  720KB (3.5)         On              Off            Off

  1.44MB (3.5)        Off             On              On

      None            On              On              On

                 FLOPPY DRIVE D CONFIGURATION

      Type           SW1/6           SW1/7          SW1/8

  360KB (5.25)        On              On             Off

  1.2MB (5.25)        On              Off             On

  720KB (3.5)         On              Off            Off

  1.44MB (3.5)        Off             On              On

      None            On              On              On

                        EPROM ADDRESS CONFIGURATION

     Address        SW3/4       SW3/5      SW3/6       SW3/7      SW3/8

        C8000h        On         On         Off         On          On

       CA000h        On         On         Off         On         Off

        CC000h        On         On         Off         Off         On

        CE000h        On         On         Off         Off        Off

        D0000h        On         Off         On         On          On

        D2000h        On         Off         On         On         Off

        D4000h        On         Off         On         Off         On

        D6000h        On         Off         On         Off        Off

              EPROM ADDRESS CONFIGURATION (CONT)

  Address    SW3/4      SW3/5     SW3/6      SW3/7     SW3/8

  D8000h       On        Off       Off         On        On

  DA000h       On        Off       Off         On       Off

  DC000h       On        Off       Off        Off        On

  DE000h       On        Off       Off        Off       Off

  E0000h      Off        Off        On         On        On

  E2000h      Off        Off        On         On       Off

  E4000h      Off        Off        On        Off        On

  E6000h      Off        Off        On        Off       Off

  E8000h      Off        Off       Off         On        On

  EA000h      Off        Off       Off         On       Off

  EC000h      Off        Off       Off        Off        On

  EE000h      Off        Off       Off        Off       Off

                       MISCELLANEOUS TECHNICAL NOTE

  NOTE 1: Due to the tight tolerances in the construction of a 3.5"
  floppy disk, the write current applied to the heads of the drive needs
  to be adjusted for either 720KB disks or 1.44MB disks. Floppy disk
  drive manufactures have used three different mechanisms to modify the
  write current. They are: TYPE 1:These drives read the current on pin 2
  of the interface cable, a 1.44MB disk is assumed for a high current,
  and a 720KB disk is assumed for a low current. TYPE 2: These drives
  have a sensor that looks for a cutout in the plastic shell of the disk.
  If the cutout is present, a 1.44MB disk is assumed. TYPE 3: These
  drives are found on the IBM PS/2 line of products. They read the
  current on pin 2 of the interface cable in the opposite manner of TYPE
  1s. That is, a high current signifies a 720KB disk and a low current a
  1.44MB disk.

  NOTE 2: If you have installed more than 2 floppy drives in a system,
  you have a choice on how the controller treats the third and fourth
  drives. MODE 1 sets the drives to A:, B:, C:, & D:, in this system your
  hard drive will be the first available letter. If you have 3 drives
  installed it will be D:, and if you have all four installed it will be
  E:. MODE 2 sets your first two floppy drives to A: & B:, and assigns C:
  to the hard drive. To install additional floppy drives under this
  system you will need to load a device drive at boot time.

