HP 3000 Manuals HP 3000 Manuals
IBM 2780/3780 Comparison
Table C-1 summarizes the features of the IBM 2780 Data Transmission
Terminal and the IBM 3780 Data Communication Terminal. The information
is presented in a way that enables you to either reference specific
information for one of the two terminal types or compare the capabilities
of one terminal type against the other.
Table C-1. IBM 2780/3780 Comparison
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| | | |
| Feature | IBM 2780 | IBM 3780 |
| | | |
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| | | |
| Peripheral | 400 cpm card reader | 600 cpm card reader |
| Devices | 355 cpm card punch (optional) | 359 cpm card punch (optional) |
| | 300 lpm line printer (optional) | 425 lpm line printer (optional) |
| | | |
| Half/Full Duplex | Half duplex only | Half duplex only |
| Protocol | | |
| | | |
| Permissible | Point-to-point (leased or | Point-to-point (leased or |
| Communication | switched) Multipoint (2- or | switched) Multipoint (2- or |
| Networks | 4-wire) | 4-wire) |
| | | |
| Permissible | ASCII (nontransparent mode | ASCII (nontransparent mode |
| Transmission | only) EBCDIC (transparent or | only) EBCDIC (transparent or |
| Codes | nontransparent modes) Six-bit | nontransparent modes) |
| | transcode | |
| | | |
| Error Checking | ASCII: odd parity, VRC, and | ASCII: odd parity, VRC, and |
| | eight-bit LRC EBCDIC: 16-bit | eight-bit LRC EBCDIC: 16-bit |
| | CRC Six-bit transcode: 12-bit | CRC |
| | CRC | |
| | | |
| Permissable | 1200, 2000,2400,4800 bps | 1200, 1800, 2400, 3600, 4800, |
| Transmission | | 7200 bps |
| Rates | | |
| | | |
| Buffers | One 400-byte buffer used for | Two 512-byte buffers used |
| | either input or output | simultaneously for input or |
| | | output |
| | | |
| Accept Horizontal | Yes (optional) | Yes |
| Tablulation Codes | | |
| | | |
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Table C-1. IBM 2780/3780 Comparison (cont.)
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| | | |
| Feature | IBM 2780 | IBM 3780 |
| | | |
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| | | |
| Accept Vertical Forms | Yes | Yes |
| Control Codes | | |
| | | |
| Transmit and Receive | Yes (optional, applies only to | Yes (optional, applies only to |
| in Transparent Mode | EBCDIC code) | EBCDI C code) |
| | | |
| Short Record | Yes (user must supply EM | Yes (done automatically; user |
| Truncation | control control characters in | does not need to supply EM or |
| | the data) | IRS control characters in the |
| | | data) |
| | | |
| Blanks Compression | No | Yes (done automatically; user |
| | | does not need to supply control |
| | | characters in the data) |
| | | |
| Maximum Blocking | 2 (optionally 7) | Nontransparent mode: 255 |
| Factor | | Transparent mode: 1 |
| | | (optionally 6) |
| | | |
| Generate WACK & TTD | No | Yes |
| Sequences when | | |
| Temporarily Unable to | | |
| Transmit or Receive | | |
| | | |
| Intermediate Block | ASCII: US BCC EBCDIC: IUS BCC | ASCII: RS (no BCC) EBCDIC: IRS |
| Terminator Character | Six-bit transcode: ITB BCC | (no BCC) Receive mode: will |
| | | not accept IUS BCC |
| | | |
| Recognize WACK | Yes (receive mode only) | Yes |
| | | |
| Component Select | [ESC] (followed by any carriage | DC1 specifies a printer DC2 or |
| Codes (point-to-point | control code specifies a | DC3 specifies punch |
| only) | printer [ESC]-4 specifies punch | |
| | | |
| SOH at Start of | Treated as an STX | Not recognized |
| Receive Text | | |
| | | |
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