Scientific Solutions ® Inc.


Product Description

Our Solution Includes

Key Features


Functional Description

Digital-to-Analog Conversion

Digital I/O


Technical Specifications

The DADIO has two primary functions: digital-to-analog conversion and digital I/O. The DADIO features 4 independent 12-bit digital-to-analog converters. All four DACs can change output states simultaneously (doubled buffered) or independently. The DADIO also features 24 lines of programmable digital I/O.


  • Compatible 100% with the original version!
  • 4 channels of Digital-to-Analog conversion
  • 24 bits of Digital I/O

The DADIO was first introduced in 1981. It has been available and supported continuously ever since, and is used in many diverse applications including laboratory testing, entertainment digital audio and multi-sonic music synthesis, laser control, and factory automation.

arrowProduct Description

Four independent 12-bit digital to analog (DAC) converters deliver 5mA across one of four output ranges. The four DACs can change their outputs individually or simultaneously. 24 lines of TTL compatible digital I/O complete this multipurpose product. Our optional LabPac for DOS or LabPac32 for Windows software provides a flexible, multipurpose interface for customized programs using any language.

arrowOur Solution Includes

arrowKey Features


arrowFunctional Description

Both DADIO functions are on one full length PC board. Interfacing to external devices is handled through standard, RF shielded D-shell connectors. Software communicates through sixteen 8-bit I/O locations (using the IN/OUT instructions). Programming information is in the manual.

arrowDigital-to-Analog Conversion (DAC)

Four independent 12-bit digital to analog (DAC) converters source 5mA on four voltage ranges. The four voltage ranges, independently selectable (jumper blocks) for each DAC, are: 0 - 10V, 0 - 5V, ±10V, and ±5V. The analog outputs are located on a 9-pin D-shell connector. The DACs are double buffered and can change either individually or simultaneously.

arrowDigital Input/Output (DIO)

The 24 lines of TTL compatible I/O (8255A) are addressable in two groups of eight and two groups of four:

All outputs are latched. Simple input is unlatched while strobed input is latched. Digital I/O is programmed with four 8-bit I/O locations, one command register configures the 24 lines and three I/O locations reflect the TTL data. Each line sources 200uA or sinks 1.7mA and is located on 25-pin D-shell connector.


Hardware interrupts allow the computer's processor to react to special events when they occur. The DADIO provides two software enabled sources for interrupts (the handshake strobes for digital I/O). External sources can also be used.

arrowTechnical Specifications

DADIO / ISA Digital Input/Output Characteristics
Number of bits 24 bits of Digital I/O
Programmable Modes Full 8255 support
  • Mode0 - Basic I/O
  • Mode 1 - Strobed I/O
  • Mode 2 - Strobed Bi-Directional
Data Transfer Programmed I/O
Logic Thresholds TTL
Current Source 200 microamps
Current Sink 1.7 milliamps

DADIO / ISA Physical Characteristics
ISA Card Dimensions (aprox.) 4.2" high x 13" long (107mm x 330mm)
Data Connectors Digital I/O: DB25
Analog Out: DE9

DADIO / ISA System Resources
Bus Interface Single 8-bit or 16-bit ISA slot
IRQ Channels IRQ 2 -7, jumper selectable
Address 16 I/O locations Required
Any I/O Address, switch selectable
Bus Load 1 TTL load/bus line maximum

DADIO / ISA Environmental Specifications
Operating Temperature 0º to 70º Celsius
Storage Temperature -25º to +85º Celsius
Relative Humidity To 95% non-condensing
Agency Approvals Class A, CE-Mark