CHAPTER 10: Emulation Capabilities
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10. Emulation Capabilities
The LinkUp 5294 emulates an IBM 525l model 12 Remote Workstation Controller, 5294 or 5394 Remote
Cluster Controller. It is designed with a variety of Terminal and Printer Modules to let virtually any ASCII
terminal or printer communicate with an AS/400 host computer as if it were actual IBM 5251 model 11
or 529x Workstation or 52xx Printers.
10.1 5250 Display Emulation
Each of the Terminal Modules supports all of the 5250 screen handling facilities of an actual 5251 model
11 or 529x workstation. This includes cursor-positioning and display attributes such as:
• Reverse Image
• Nondisplay
• Blink
• Column Separator
• High-intensity
• Underscore
The above attributes are supported only to the extent that your ASCII terminal can support them.
The LinkUp 5294 also uses many special techniques to optimize the emulation provided to your ASCII
terminal:
•
Screen Optimization —
Instead of clearing and repainting your screen’s data for every update, the
LinkUp 5294 updates your screen by clearing and repainting only for new character changes,
keeping the amount of screen updating to a minimum.
•
Terminal’s Unique Features —
These are incorporated into the corresponding Terminal Module if
they are proven advantageous. If not, the LinkUp 5294 compensates. To prevent those ASCII
terminals with automatic scrolling capabilities from automatically scrolling, since an actual IBM
workstation does not support this, the LinkUp 5294 restricts data from being entered to the last
character position (row 24, column 80) on the terminal’s screen.
•
Status Line
— Five indicators are displayed on row 24 of your terminal’s screen while you are in
session with the System/3X host (Emulation Mode). The LinkUp 5294 displays this line the first time
your terminal enters Emulation Mode; afterwards, you may toggle it on (or off) using the
appropriate key sequence (corresponding to the function of Toggle Status Line/Toggle Indicators.)
These five indicators are listed below:
SYS AVAIL —
System Available indicator is set (turned on) whenever the terminal is receiving polls
from the System/3X host.
MSG WT —
Message Waiting indicator, controlled by the host, is set (turned on) whenever you have
messages waiting to be read.
INS MODE —
Insert Mode indicator is set (turned on) whenever the INSERT key has been pressed.
Insert Mode can be reset (turned off) by pressing the ERROR RESET or one of the Aid Generating
keys.
INPUT INH —
Input Inhibited indicator is set (turned on) after an Aid Generating key is pressed.
This indicates the keyboard has been locked by the host and the operator should not type any data.