Sega Saturn Game Basic: Part 1 (Windows Communication Cable)
13In this first part I just take a look at what is in the communications cable (通信ケーブル) that comes bundled with "GAME BASIC for SEGA SATURN" (ゲームベーシック フォー セガサターン).
I don't plan to use this cable as I have a Saturn keyboard & floppy drive so should be able to use Game Basic directly on the Saturn itself. Let's see.
The Windows end of the cable is a female DB25 configured for RS232. Of the 25 pins, just three are used: Tx, Rx and signal ground.
The Saturn end has a plug for the custom Communications Connector that (officially) can be used for connecting two Saturns together, for the Saturn Floppy Drive, or for this Windows computer communication.
In this last capacity we are using four wires.
There is an NEC D4711GB RS2323 line driver/receiver in between them with some capacitors.
The cable gives a warning that a "extension cable" should be purchased otherwise some malfunction may occur. The documentation seems to indicate that this cable is simply a straight-through RS232 or modem cable, terminating in either another DB25 or a DE9 (depending on your computer). Weird.
I've tried to document everything in the relevant Github page:
https://github.com/0ddjob/SEGA/tree/main/Saturn/Windows_Communication_Cable