SCIENTIFIC MICROSYSTEMS, INC.

OMTI 3520A, OMTI 3527A

Maximum On-board Memory

8KB

Data Bus

External

Card Size

3.5 in. form factor

Hard Drives supported

Two ST-506/412(MFM) drives on OMTI 3520A

Two ST-506/412(2,7 RLL) drives on OMTI 3527A

Floppy drives supported

None

CONNECTIONS

Function

Location

Function

Location

50-pin SCSI connector - external

J1

20-pin data cable connector - drive 1

J3

34-pin cable connector - hard drive

J2

20-pin data cable connector - drive 2

J4

Note: J1 is the interface between the host computer and the OMTI 3520A/3527A. See Miscellaneous

Technical Note.

USER CONFIGURABLE SETTINGS

Function

Label

Position

»

SCSI parity check enabled

W4

Closed

 

SCSI parity check disabled

W4

Open

»

Factory configured - do not alter

W5

Unidentified

»

Factory configured - do not alter

W6

Unidentified

»

Factory configured - do not alter

W7

Unidentified

»

Factory configured - do not alter

W8

Unidentified

»

Factory configured - do not alter

W9

Unidentified

»

Factory configured - do not alter

W10

Unidentified

»

Factory configured - do not alter

W11

Unidentified

»

Factory configured - do not alter

W12

Unidentified

»

Factory configured - do not alter

W13

Unidentified

»

Termination power from board

W14

Pins 1 & 2 closed

 

Termination power from SCSI bus

W14

Pins 2 & 3 closed

»

Factory configured - do not alter

W15

Unidentified

SCSI ID SELECTION

Setting

W1

W2

W3

»

0

Open

Open

Open

 

1

Closed

Open

Open

 

2

Open

Closed

Open

 

3

Closed

Closed

Open

 

4

Open

Open

Closed

 

5

Closed

Open

Closed

 

6

Open

Closed

Closed

 

7

Closed

Closed

Closed

MISCELLANEOUS TECHNICAL NOTE

Note: The OMTI 3520A and OMTI 3527A controllers are connected to the host system via the SCSI bus

(connector J1). Up to seven SCSI devices may be connected to this bus and an OMTI

3520A/3527A controller is considered to be one of these devices. Multliple controllers may be

attached, with each controller assigned a unique SCSI ID using jumpers W1, W2 and W3.