Browse Prior Art Database

Specialized File Transfer Interface on Ascii-5250 Protocol Converter

IP.com Disclosure Number: IPCOM000034470D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 3 page(s) / 65K

Publishing Venue

IBM

Related People

Rowlance, EJ: AUTHOR [+2]

Abstract

A specialized file transfer interface on a ASCII to 5250 protocol converter that provides improved data transfer performance and integrity is herein described. Personal computers with an asynchronous interface attachment can be attached to a 5208 either directly or through asynchronous modems (see the figure). Software necessary in the PC to provide ASCII terminal emulation can be extended to provide the ability to transfer files between the host system and the PC. To provide optimum speed and data integrity, a special interface between the PC and 5208 was designed for file transfer. This interface is activated by placing the 5208 in data transfer mode. Data transfer mode in the 5208 is turned on and off using the ASCII commands DLE STX and DLE ETX.

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Specialized File Transfer Interface on Ascii-5250 Protocol Converter

A specialized file transfer interface on a ASCII to 5250 protocol converter that provides improved data transfer performance and integrity is herein described. Personal computers with an asynchronous interface attachment can be attached to a 5208 either directly or through asynchronous modems (see the figure). Software necessary in the PC to provide ASCII terminal emulation can be extended to provide the ability to transfer files between the host system and the PC. To provide optimum speed and data integrity, a special interface between the PC and 5208 was designed for file transfer. This interface is activated by placing the 5208 in data transfer mode. Data transfer mode in the 5208 is turned on and off using the ASCII commands DLE STX and DLE ETX. For an outbound file transfer, the host system writes a record of data to the display screen emulated by the 5208 for the device address that the PC is attached to, starting at row 1, column 2. When the record of data is completely written, the host turns off the input inhibited indicator in the emulated display. This signals to the 5208 that the data is complete and can be written to the PC. The 5208 takes the screen data and sends it to the PC using the following format: DLE SOH LEN1 LEN2 Data Data ... Data LRC where: DLE SOH is the ASCII sequence indicating the start of a

data buffer, LEN1 LEN2 is a two-byte value containing the number of bytes

of data being transferred (excluding

LRC, maximum 1920), Data are the data bytes being transferred, LRC is a longitudinal redundancy check

character created by starting with a

value of 0 and exclusively ORing each

data byte and the length bytes with it. When the entire data buffer transmission is received by the PC, it calculates the LRC value independently and compares it with the v...