Screen Design Aid

Screen Design Aid (System/34 and System/36)

SDA is a utility for the IBM System/34, System/36, System/38, and AS/400 (iSeries) midrange computers.

This article refers to the S/34 and S/36 implementations of SDA. S/38 and AS/400 use a different SDA with different syntax and characteristics. See the AS/400 article for more about these midrange computers.

SDA stands for Screen Design Aid. Programmers can use SDA to create menus, display formats, or WSU skeleton programs.

IBM midrange computers utilize display stations to present information and to accept information and control from computer operators. A display station is an input/output device comprised of a monitor and a keyboard.

S/34 and S/36 applications usually involve the operator to a critical degree, whether accepting the bulk of input through display stations or controlling them. Computer programs may utilize unformatted or formatted input, and this is where SDA applies.

Language Access

In RPG II, use the WORKSTN device.

In COBOL, use the CONSOLE device.

In BASIC, OPEN a filespec and describe it as WORKSTN.

In OCL, use the PROMPT statement.

Coding For Your Audience

When the IBM System/34 was sold, a common monitor would be a monochrome 12-inch IBM 5251; in the System/36 heyday, a common monitor would be the 12-inch IBM 5291 or the color 14-inch IBM 3486.

All S/34 and S/36 display stations used 5250 protocol; S/34 allowed either 960-character displays or 1920-character displays; S/36 allowed either 1920-character displays or (rare) 3564-character displays.

Code two different display formats if it is possible that your audience might use the IBM 5252 Dual Display, which requires 960-character displays. Consider whether your audience will be using color or monochrome displays - an application developed for color-only might not function well on a monochrome display.