HwMuseum | Index

EVEREX SYSTEMS, INC.

EV-391

Data bus: 8-bit, ISA

Size: Full-length, full-height card

Hard drives supported: Two MFM ST506/412 drives

Floppy drives supported: None

CONNECTIONS

Function

Location

34-pin control cable connector-hard drive

J1

20-pin data cable connector-drive 0

J2

20-pin data cable connector-drive 1

J3

USER CONFIGURABLE SETTINGS

Function

Location

Setting

»

Normal operation

W1

pins 1 & 2 closed

 

Factory test

W1

pins 2 & 3 closed

»

Normal operation

W2

pins 1 & 2 closed

 

Factory test

W2

pins 2 & 3 closed

»

BIOS enabled

W3

closed

 

BIOS disabled

W3

open

»

I/O port address 320h

W4

pins 2 & 3 closed

 

I/O port address 324h

W4

pins 1 & 2 closed

»

BIOS size 32K or 64K

W5

pins 1 & 2 closed

 

BIOS size 16K

W5

pins 2 & 3 closed

»

8 Head hard drive with RWC (Head Select 3 invalid)

W6

pins 2 & 3 closed

 

16 head hard drive supported (Head Select 3 valid)

W6

pins 1 & 2 closed

»

Hard drive interrupt is IRQ5

W7

pins 1 & 2 closed

 

Hard drive interrupt is IRQ2

W7

pins 2 & 3 closed

Note:SW1/switches 5, 6, 7, and 8 are reserved for BIOS functions and should not be altered.

BIOS DRIVE TYPE TABLE - SW1

(FOR EPROM REV. 3.92A)

#

Jumper 1

Drv. 1

Jumper 2

Drv. 1

Jumper 3

Drv. 0

Jumper 4

Drv. 0

Cap.

Hds.

Cyls.

0

closed

closed

closed

closed

42MB

5

977

1

open

closed

open

closed

21MB

4

615

2

closed

open

closed

open

10MB

2

615

3

open

open

open

open

10MB

4

306

MISCELLANEOUS TECHNICAL NOTES

This controller has a built-in low-level format program. To enter the program run the DEBUG utility supplied with DOS and at the prompt enter: G=C800:5.