IBM 5250 терминалдары: тарихы мен қазіргі қолданысы

Family of block oriented terminals

IBM 5250 is a family of block oriented terminals originally introduced with the IBM System/34 midrange computer systems in 1977. It also connects to the later System/36, System/38, and IBM AS/400 systems, and to IBM Power Systems systems running IBM i, as well as the Series/1 minicomputer.

Field attributes also define the type of data the operator can enter into a field, and specify other control information for the field. A field can be defined as alpha only, numeric only, or alphanumeric. Auto enter simulates an ENTER key press at the conclusion of the field. Bypass automatically skips over a field in the screen. Duplicate enable allows the operator to press the DUP key in a field, entering a special code which is interpreted by the application program – typically duplicating data in this field from the previous record or line. Field exit required forces the operator to manually exit this field, rather than automatically advancing to the next field after entering the last character. Mandatory entry specifies that the operator must enter data in this field and is not allowed to tab over it. Monocase translates lower case characters entered into this field to upper case. Mandatory fill specifies that this field must be entirely filled if any data is entered into it. Right adjust will right adjust data entered in a field when the operator exits the field. Signed numeric reserves the rightmost position of a field for a sign – blank for positive or ' ' for negative.

The 5250 is a block oriented terminal similar to, but not compatible with, the IBM 3270. Robustly constructed, 5251 terminals weigh roughly The devices generate an audible clicking sound as the user types, similar to the electric typewriters of the era. The 5250 data stream definition has been refined over time to include GUI elements such as pop up windowing, check and option boxes, mouse handling, and pull down menus. The IBM 3180 added support for seven colors pink, red, blue, yellow, green, white, and turquoise. A protocol called the IBM 5250 Data Stream interpreted field attributes such as blinking, non display, high intensity, reverse image, underline, and column separators and was used in combination to create colors. Normal text was presented as green on a 3180 color terminal, but high intensity became white. Column separators became yellow. Blinking became red. Underlined text was presented as blue. High intensity blinking became pink. High intensity column separators became turquoise. The term "5250" now refers to the data stream itself. No physical 5250 terminals with their bulky twinax cables still exist, although they were occasionally still used to provide a "connection of last resort," hard wired to the host computer. Today, it is more common to use PC or web based terminal emulation packages that can interpret and display 5250 data streams.

Telnet 5250, or TN5250 describes either the process of sending and receiving 5250 data streams using the telnet protocol or the software that emulates a 5250 class terminal communication via that process. TN5250 allows a 5250 terminal emulator to communicate over a TCP/IP network instead of an SNA network. Standard telnet clients cannot be used as a substitute for TN5250 clients, as they use a different data stream format.

An interface was created to connect to the Twinax port of a 5250 terminal and communicate with it like an AS/400 host. It currently provides VT52 emulation and a shell on the system to which the adapter is connected.

The IBM 3179 exists as a 3270 and a 5250 terminal.

The IBM 3180 exists as a 3270 and a 5250 terminal.

Does not include an internal display. An external monitor is connected via VGA.

Does not include an internal display. An external monitor is connected via VGA.