Model T Serial Cable: Difference between revisions
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*[https://www.startech.com/Cables/Serial-Parallel-PS-2/DB9-DB25/10-ft-Cross-Wired-DB9-DB25-Serial-Null-Modem-Cable~SCNM925FM StarTech SCNM925FM] (no DCD, Shield to Shield but not to pin1 on 25M) | *[https://www.startech.com/Cables/Serial-Parallel-PS-2/DB9-DB25/10-ft-Cross-Wired-DB9-DB25-Serial-Null-Modem-Cable~SCNM925FM StarTech SCNM925FM] (no DCD, Shield to Shield but not to pin1 on 25M) | ||
Slightly less ideal cables. | Slightly less ideal cables. These are good too, but using software flow control only: | ||
:These cables work fine for TPDD client/server connection, and almost everything else, since there isn't even any way to *set* hardware flow control in either BASIC or TELCOM anyway. | :These cables work fine for TPDD client/server connection, and almost everything else, since there isn't even any way to *set* hardware flow control in either BASIC or TELCOM anyway. | ||
:But the hardware in the M100 *can* actually do RTS/CTS, if you manipulate the UART registers yourself from a machine language program. The only software I know of that does this is HTERM. So these cables are NOT suitable for HTERM | :But the hardware in the M100 *can* actually do RTS/CTS, if you manipulate the UART registers yourself from a machine language program. The only software I know of that does this is HTERM. So these cables are NOT suitable for HTERM | ||
Revision as of 02:36, 31 October 2017
The ideal cable to go from a PC to a Model 100, 102, 200, or 600, is "9F/25M serial null-modem full-handshake".
The serial ports on Models 100-600 are wired DTE, the same as a com port on a PC, but with a female connector, unlike any pc.
This is a backwards configuration from everything else today. There is some suggestion that maybe this is actually the original standard, and IBM came along later and changed it by putting male connectors on their PCs, but in any event, 25pin DTE ports being male has been the universal standard now for decades.
- Any modem or printer or digital scale or any other kind of peripheral with a serial connection will be wired DCE with a female connector, usually 25 pin.
- Any serial port card or usb serial adapter for a PC will be wired DTE with a male connector, usually 9 pin.
That means that usually you always need some kind of adapter between a PC and a M100/102/200/600.
The easiest way to connect with parts you are most likely to already have lying around, is to use a 9F/25M Modem Cable combined with a 9M/F Null-Modem Adapter.
Ideal, all-in-one cables:
- C2G 03019 (fake DCD from DSR/DTR, Shield to pin1 on 25M)
- Amphenol CS-DSNL4259MF-005 (fake DCD from DSR/DTR, Shield to pin1 on 25M)
- StarTech SCNM925FM (no DCD, Shield to Shield but not to pin1 on 25M)
Slightly less ideal cables. These are good too, but using software flow control only:
- These cables work fine for TPDD client/server connection, and almost everything else, since there isn't even any way to *set* hardware flow control in either BASIC or TELCOM anyway.
- But the hardware in the M100 *can* actually do RTS/CTS, if you manipulate the UART registers yourself from a machine language program. The only software I know of that does this is HTERM. So these cables are NOT suitable for HTERM
- Shorts RTS/CTS to self-satisfy, but curiously, actually passes DTR/DSR correctly
- Same as Monoprice 479
- This "HP PLotter" cable is bizarre.
- DCD<-->RTS / DSR+CTS<-->DTS
- WTF??? HP are monsters.
- Same as Monoprice 479
- DTR<-->DCD+RTS+CTS