This project is a Wifi - RS232 Serial adapter for getting vintage computers connected to the internet (telnet or http). Use it to connect your vintage computer to a telnet BBS or other internet resources. At it's heart is a Wemos ESP8266 wifi-enabled controller. This project differs from other Wifi Serial adapters in that it adds a micro-SD card module for reading and writing data. The intended use case is for people who have a vintage computer but have no ability (or desire) to create floppies, and doesn't want to modify the computer (by installing a permanent floppy emulation solution something like a Gotek). V2 also adds a 128x64 display and 4 navigation buttons to make setup easier. V3 upgrades the processor to an ESP32, add a battery charging circuit and power switch, and upgrades the RS232 level shifting to a MAX3242 device which is capable of driving all serial lines.
If you prefer to save yourself some time, I have some units (fully assembled or kit) available for sale. I had quite a few PCB's made up and I am trying to keep these as cheap as possible. You can purchase on Tindie.
The first thing you probably want to do is try connecting to a BBS. Follow these steps to get connected to your wifi, save your settings and connect to a telnet BBS.
- Power on your WiRSa, and using the buttons and menu system on the device's display, navigate to Settings -> Baud Rate and choose the speed that your computer's serial RS232 port will communicate at.
- Plug the WiRSa into your computer's serial port. Set your terminal program to the correct speed and connect. If you just hit enter, you should see a menu in terminal. Go to "MODEM Mode".
- Now you will be expected to type in some special "AT" commands. Type AT? for a list of commands.
- Let's get connected to your Wifi. Keep in mind the WiRSa can only connect to 2.4 GHz connections, 5.8 GHz aren't supported. Use the following commands:
- Enter your router's SSID name. Type AT$SSID=ssid_name
- Now enter your wifi password with AT$PASS=password
- Type ATC1 to connect. If your username/password are correct, you should see a connection message and your device's IP address.
- You probably don't want to type all that in every time you power up your WiRSa, save all of your settings by typing AT&W . Now the next time you go into MODEM mode, you will automatically be connected to your router.
- Now try connecting to one of the speed dial connections. Type AT&V to display your current settings including the speed dial list. To connect, use ATDSN where N is a number 0-9 of the entry. To connect to the first entry, type ATDS0 . To connect to any other telnet system directly, type ATDTbbs.somewhere.com:23 .
This began as a device I built for the filming of Apple TV's "The Shining Girls". There were a number of scenes involving computer terminals. They had the terminals but no idea how to display anything on them. I came up with this device as a means to display a static block of text at the terminal or "playback" a text file - ie: when the actor hits a key on the keyboard, regardless of what key is pressed - the next character from the text file gets printed. This creates the illusion that the actor is actually typing the document in real-time but they're really just mashing keys. I've included this text playback feature in the firmware. The text file is read directly from the SD card. I had previously used a Wemos to build a Wifi modem for my Commodore 64 user port. This device is basically the combination of those 2 projects.
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The firmware has 3 main functions:
- MODEM mode, for telnet/BBS use. The Modem Mode of the firmware is based on "WiFi SIXFOUR" (https://github.com/thErZAgH/c64modem), which in turn was based on the "Virtual modem for ESP8266" (https://github.com/jsalin/esp8266_modem).
- Text Playback mode, for reading and printing text files from the SD card over the serial line.
- File Transfer mode which offers the ability to send and receive data from the SD card with the host computer (so long as the host computer is running a terminal software which supports file transfer). Currently the file transfer protocols XMODEM and YMODEM are supported. There are plans to also implement YMODEM Batch, ZMODEM and KERMIT.
On a new build, the default serial settings will be 9600 baud, 8-N-1. You can change the baud rate while in Modem Mode (with the SET BAUD RATE (AT$SB=) command) or in the Settings menu on the display.
Because this is similar to the Paul Rickards WiFi232 device, you can refer to that documentation for Modem Mode usage & commands.
If you have a WiRSa and want to upgrade the firware to the latest version found here, you have 2 options...
- Install the Arduino software and download the /Firmware/WiRSa/WiRSa.ino file. Load the .ino file and compile/upload to the device. You may need to resolve some library dependencies.
- Much simpler way is to download the precompiled binary at /Firmware/WiRSa/WiRSa.bin. Download ESP32FlashTool and use it to upload the new version. In the ESP32FlashTool software, simply choose the COM port, select the .bin file, and click Flash.
For programming, remove the 2 white jumpers. This disables the RS232-TTL converter which sometimes causes interference when programming. After programming, replace jumpers for normal use.
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The WiRSA is based on a few cheaply available components and a custom PCB which ties them all together. The components needed are: • WiRSa v3 PCB (populated with some SMD components including SD card reader, MAX3243 line driver, resistors, power switch and JST battery connector) • ESP-WROOM-32D Dev Board with integrated OLED & battery charging circuit • (4) 6x6x9mm momentary switches, right-angle • DE-9 (DB9) female connector, right angle Everything gets soldered to a custom PCB. The KiCAD schematic, PCB and Gerber files are all included in this repo.
The enclosure has been created in OpenSCAD and the source is included here as well as a resulting STL. It has been redesigned to use snap-fittings. STL's are provided for both a version with or without a battery compartment (and battery power switch cover).
Should you have any questions or problems, feel free to email me directly at [email protected].