...because we can't all be on the bleeding edge...





UNIVERSAL FLOPPY DISK CONTROLLER

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

CONNECTIONS

Function

Label

Function

Label

34-pin floppy drive interface

J1

34-pin floppy drive interface

J3

37-pin floppy drive interface

J2

   

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 MISCELLANEOUS TECHNICAL NOTE 2)

SW3/1

Off

 

Drive order will be MODE 2 (see MISCELLANEOUS TECHNICAL NOTE 2)

SW3/1

On

 

UFDC is the primary floppy drive controller

SW3/2

Off

 

UFDC is the secondary floppy drive controller

SW3/2

On

EPROM enabled

SW3/3

On

 

EPROM disabled

SW3/3

Off

TYPE 1 or 2 drives (see MISCELLANEOUS TECHNICAL NOTE 1)

W1

Pins 1 & 2 closed

 

TYPE 2 or 3 drives (see MISCELLANEOUS TECHNICAL NOTE 1)

W1

Pins 2 & 3 closed

Pin 2 on the interface cable is an output signal

W2

Pins 1 & 2 closed

 

Pin 2 on the interface cable is an input signal (TYPE 2 drives only)

W2

Pins 2 & 3 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.