Hello Santiago,
Welcome to the group. In previous times an antenna, PC (personal computer), transceiver (HF, VHF, or UHF), TNC (terminal node connector, cables to connect the transceiver-TNC-PC together, and software that TNC required to convert the data the PC processed into electrical data the transceiver was able to use for transmitting and receiving. As computers became more powerful to handle more tasks and programmers wrote better code some smart people reasoned they could write software to replace the function of the TNC requiring one less piece of hardware. The software utilized the sound card that most PC's were now using (in the early days, after sound cards were developed, having a sound card in your PC was an option, until it became a standard). You ask many questions that may not be answered here at one query. But, I will try.? In addition to your Yaesu FTM-3100R VHF analog transceiver, trying to answer your first question, presuming you want to use the basic function of communicating and the advanced function of a BBS, you will require a software application (program), a PC (with at least a i486 CPU 16-bit or higher) running Linux/Unix, OS/X, or Windows, and the cabling required for your 3100 and PC to communicate. Be aware that packet in different parts of the world is still very active and thriving, while in the U.S. this is not the case. You might say that APRS is alive an well. APRS is a function of packet radio. The keyboard to keyboard communicating using packet radio is stagnant in the majority of the U.S. (I would really like to see a comeback in this arena).
Regarding the Raspberry Pi family and Coastal ChipWorks TNC-Pi: TNC-X; both require software. The Raspberry Pi requires an OS (operating system) and can be purchased with an SD card that has several versions of Linux for the Raspberry Pi that can be installed, known as the NOOBS SD card. You can even install a version of Windows 10, if you must. Additionally, you require a software application that permits the TNC-X to communicate with the your computer through your transceiver.
Is the Yaesu FTM-3100R a good rig for packet? I don't have an answer for that since I have never used that radio. I think most Amateur Radio transceivers are good rigs for packet radio providing certain requirements are met. My packet station uses a Kenwood TH-215 HT that I purchased new in 1987. It outputs 0.5w/5w. It served me well for base radio, mobile radio, and portable radio. It has been serving me well for packet radio for 31 years.
Yes, you will require a cable to connect the TNC-X to the transceiver. If you can obtain the wiring diagram/schematic you can make your own, or there are places via the Internet where you can purchase the appropriate cabling. For example, hammadeparts dot com there are a couple listed that might apply to your radio ranging from $18 $25 USD. I think the cable for your specific radio plugs into the microphone port requiring a RJ-12 connector on one end of the cable and USB on the end that plugs into the RPi/TNC-X.
A minimal starting kit? Coastal ChipWorks, on vacation until October 29, 2019, has?TNC-Pi 2 (TNC-X for Raspberry Pi B+, Pi 2, and Pi3) wired and tested ($65).??There are other options on the website that I suggest you check.
I hope these answers are helpful to you. Best 73 KB8AMZ
