Photo of splitter cable
Drawing of RS232 cables
Last update: Oktober 10th2010
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To be able to print from the TI99/4a to a printer connected to your PC, you have to connect a serial port from to TI99/4a to a serial port of the PC. The following table shows the function of the RS232 signals on a 9 pin and 25 pin subd connector for a computer:
| 9 pin subd | 25 pin subd | term | description | meaning |
|---|---|---|---|---|
| 1 | 8 | DCD | Data Carrier Detect | A control signal to the computer. The modem is receiving a valid carrier signal from the remote modem. |
| 2 | 3 | RxD | Receive Data | The data signal to the computer. |
| 3 | 2 | TxD | Transmit Data | The data signal from the computer. |
| 4 | 20 | DTR | Data Terminal Ready | A control signal from the computer to indicate that it is ready to receive date. |
| 5 | 7 | GND | Ground | The common signal ground connection. All the other signals refer to this reference. This must be connected at both connectors. |
| 6 | 6 | DSR | Data Set Ready | A control signal to the computer from a sending device indicating that the device is ready to send data. |
| 7 | 4 | RTS | Request To Send | A control signal from the computer to indicate that it can receive data. |
| 8 | 5 | CTS | Clear To Send | A control signal to the computer to indicate that the receiver is ready to receive data. The receiver can drop this line when for instance its buffer is full. |
| 9 | 22 | RI | Ring Indicator | A control signal to the computer indicating the phone line is ringing. |
When using the Ti99Print program, the TI99/4a is the transmiting device and the PC is the receiving device. When making a serial connection between two computers, signals on a RS232 port can't be connected one-by-one. The following table shows a typical connection between two computers:
| Computer 1 (PC) |
Computer 2 (TI99) |
|---|---|
| RxD | TxD |
| TxD | RxD |
| DCD/DSR | DTR |
| DTR | DCD/DSR |
| GND | GND |
| RTS | CTS |
| CTS | RTS |
For myself I have created a splitter cable for the RS232 card and then
use a normal (standard) RS232 cross cable for connecting my TI99 to a
PC COM-port. Click on the thumbnails below for a picture of my RS232 splitter
cable and drawings of the splitter cable, cross cable and a cable for conneting
the TI99 RS232/1 to a pC COM port directly.
Photo of splitter cable
Drawing of RS232 cables