I am marking the battery option back in stock, as I have some on order - but there may be a slight delay in shipping these orders

Update 1/30/2026: New firmware v3.06 released, Port Forwarding added to SLIP/PPP!

Update 1/26/2026: New firmware v3.05 released, SLIP Gateway mode added!

Update 1/22/2026: New firmware v3.04 released, PPP Gateway mode added!

Update 1/8/2026: New firmware v3.03 released, ZModem transfer protocol added, greatly improved web config interface!

RetroDisks WiRSa (Wifi RS232 adapter) is a Wifi/Serial adapter with features never seen on these types of devices before:

• V3 upgrades from a ESP8266 to a much more powerful ESP-WROOM-32D chipset with USB-C connector
• FULL RS232 breakout into the CPU board, allowing support for DSR/DTR, RTS/CTS, Carrier Detect and Ring Indicator pins.
• Built-in battery / charge circuit for on-the-go connectivity. Battery option includes a 2000mah 3.7 Li-Po which can power the WiRSa for about 14 hours!
• Built-in micro SD card reader - with a capable terminal software on the target computer, you can transfer binary files directly from the SD card. (XModem, YModem and ZModem transfer protocols currently tested/working with others coming soon)
• Text display/playback which can read file from the SD card and send them out across the serial line for display on your computer or terminal.
• Integrated two-color 128x64 OLED display which allows you to change settings, initiate commands and view data transmissions in real-time.
• MODEM mode which accepts AT-style commands to telnet into your favorite online BBS.
• Built-in web server allows you to view device status, modify all config options, and upload/download files from an attached SD card.
• Case option available - custom 3D-printed enclosure.
• Kit form available to save you money - you do the soldering. All through-hole, assembly instructions on the Github. (The board does have some surface-mount components, but these will come pre-installed!)

The serial port is a female DB9 (DE9) connector. Please ensure you have the proper serial adapter if your computer has a connector other than male DB9. Please look carefully at the DB9 connector, due to the included nuts you may need to use a serial cable to connect it to your computer, or you can remove the nuts but the metal shielding will be loose.

Without the battery option, the adapter must be externally powered via a USB-C** cable. You will have to supply your own USB-C cable and power source - an old phone charger works perfectly. If you choose the battery option, the battery will be charged automatically by the USB plug. If you're like me and have multiple computers you might use this with, having the battery option will make your life so much easier. Want to quickly test something or transfer a small file over Xmodem? No need to set up external power.

NO SD card is included with any of the options, even though it may be pictured - this is for illustration only. My recommendation would be a 16 or 32 GB Sandisk micro-SD card, formatted as FAT32.

PPP Mode: This feature is in beta. Has been tested so far on Windows 98 using Dialup Networking. While in modem-mode dial "777" to put the modem into PPP mode. Create a new connection, protocol check TCP/IP only, disable "header compression" and "log onto remote network". After dialing modem enters PPP mode and assigns an IP. I have tested ping, telnet, IRC, browsing and downloading - works well, but YMMV. If you test this please provide me with some feedback on your results!

The Kit Assembly Instructions are available at the Github repo.