The first image vividly reminds me of the excitement I felt when I got my first modem in 1984...
But one cannot have that feeling nowadays... 300bps was standard when fullduplex..

There are RF modems on the market since long. I myself have a pair of vintage 0.5W Satelline modems that use a 25kHz channel in the 420MHz band.
With these one can, with antennas in a height of 1 meter above surface, connect with full hardware handshaking at 19200bps fullduplex over a distance of up to 4 kilometers. With antennas mounted higher, there are distances up to 17 kilometers possible.

Ooh, looks interesting. Agreed that the ESP32 looks good. I have exactly zero experience with messing around with this sort of microcontrollers, but want to change that. On the other hand I've been involved with WiFi engineering for the better part of a decade now (with CWNP certificates to show for it), so if we hit weird stuff there I might be able to help.

i did it once, on a breadboard, seems to work fine.

matze79 wrote:

HSome UARTS support Mbit/s speeds so its really Possible to create a faster solution then 10kb/s 😀
With 16C650 we can transfer data at speeds up to 3mbits.

Nice project! ^^ Though a 16550 may suffice perhaps, it can do 1.5MBit/s if driven by
a higher clock source (though that might require adapted software).
https://www.lammertbies.nl/comm/info/serial-uart.html

Hm seems i can`t get zmodem transfers working properly from linux telnet login to the 386SX.

The ESP8266 does not like it.. i ordered now a ESP32 and will retry 😀

Maybe we can make the Card supporting both UARTs as they are Pin Combatible 😀

matze79 wrote:

Pin Combatible 😀

Fight! The more pins, the better!

matze79 wrote:

My Firsts Test where done with Ximodem Firmware and SLIP Firmware and the ESP8266.
Such a Modem Plug can be made for less then 5$ Bucks from Offshelf Parts.
MAX2323 Module and ESP8266 Module ~3-5$, a bit of Wire and 2 Diodes to drop down to 3,3-3,6V from 5V.

this is insane, I JUST POSTED asking how to get this done.

Can you share info on how to make an ESP8266-based wifi serial modem?

You need:
ESP8266-01 or maybe ESP-32 if you want more Features.
MAX2323 Module
A 3,3V Power Source, some Cables.. or a 5V Powersource and 2 Diodes 1N4001 for dropping to 3,6V.

On my MAX2323 Module the RX/TX Pins are already crossover (RX = TX, TX = RX) which i found pretty annonying 😀 i did not excpect they name it wrong.

Its simply a Matter of wiring the both modules together and supply them with 3,3-3,6V..

maybe i can make a Quick Drawing 😀

Also needed:
- Arduino Building Enviroment
- Zimodem Firmware
- https://github.com/bozimmerman/Zimodem
For Flashing Mode one Pin of ESP needs to be put on GND.
Its the Same Firmware used on C64 WIFI Adapter.

It already works with the Supplied Firmware preinstalled on the ESP8266, but the firmware sucks 😀

There are also ready made RS232 Plugs, also with SDCard Slot and other Stuff so you can send yourself Files over ZMODEM from SDCard Reader on the RS232 Plug.

But they cost a lot.. if you do it yourself you're much cheaper.

Maybe i can make a simple interposer PCB.. such a small PCB only will cost about 1-2$

I'm really interested in this. Would it be possible to simulate Hayes modem and thus play some multiplayer DOS games Over the internet?

matze79 wrote:

The Lack of Hardware Handshaking with ESP8266 will give me only one option, move to ESP32. The ESP8266 has some drawbacks, recie […]
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The Lack of Hardware Handshaking with ESP8266 will give me only one option, move to ESP32.
The ESP8266 has some drawbacks, recieve buffer is too small 😀

My Firsts Test where done with Ximodem Firmware and SLIP Firmware and the ESP8266.
Such a Modem Plug can be made for less then 5$ Bucks from Offshelf Parts.
MAX2323 Module and ESP8266 Module ~3-5$, a bit of Wire and 2 Diodes to drop down to 3,3-3,6V from 5V.

Some UARTS support Mbit/s speeds so its really Possible to create a faster solution then 10kb/s 😀
With 16C650 we can transfer data at speeds up to 3mbits.

The WIFI232 supports baud rates up to 115.2K http://biosrhythm.com/?page_id=1453

And it uses an ESP8266

Yeah but still has the Problem that ESP8266 has only small buffers 😀

i rather would go for ESP32, which is bit more expensive but has Proper Support for Handshaking and more.
Bigger Buffers, less Problems during file transfers.. (Waiting for ESP8266... because buffer is full)

matze79 wrote:

Its simply a Matter of wiring the both modules together and supply them with 3,3-3,6V..

maybe i can make a Quick Drawing 😀

That would be great but also ideas on how to get voltage for a self contained unit... Maybe from USB with a voltage regulator downing it to 3.3/3.6V?

i just use Diodes. Each dropping 0.7v

Sorry to revive this old thread.

I was just wondering, is there actually any interest or new info on the topic of an ESP8266 ISA card? I mean with a desktop PC it is not that big of a deal to use one of the existing serial ports and an external power supply?

I wanted to have an ESP8266 on a laptop which does not have an external serial port even so I have created a PCMCIA card that has a UART and ESP8266 onboard. I am currently using a crystal to do max 460800 baud which seemed to be the limit on the ESP8266 without some software changes. Eventually I would like to look at how to do 1mbaud with the ESP8266, which is the max baud rate the UART I am using can do (with 16mhz crystal). I implemented all the control lines (cts/rts/dtr/dcd etc etc) and tested mainly with Zimodem.

I think it would be near trivial to adapt this to an ISA card, almost simpler. For the PCMCIA I had to deal with the CIS etc so that the card can be configured by the pcmcia host adapter etc. For an ISA card I can get rid of all of that, throw some jumpers on for selecting interrupt/io and do some small modification to the address decoding. As there is no physical form factor constraint that also makes it easier.

I am not trying to sell anything here, if it was worth doing I will share anything I contribute. If I am the only one interested though I think I am happy enough with a PCMCIA card as I actually do most my retro computing with little dos palmtops.

Hi, I was thinking about a different approach, embedding a small WiFi router, which connects to wireless network and converts it to a normal wired ethernet connection. Then that ethernet connection would be internally connected to a regular Ethernet ISA card or PCMCIA card. There are cheap OpenWRT capable modules, like $5 A5-V11 mini router, which could be integrated into such solution. Here is how it would look like:

This PCB New NE2000-compatible ISA network card could be redesigned in such a way that it would be easy to add such WiFi module there, and then you would just need to load a DOS packet driver and be ready to go.

It is also possible to buy even smaller, industrial OpenWRT modules like this one and just solder them onto dedicated pads on PCB

In theory you could even use the USB port for flash drives and create an internal file server, for easy file transfer.

The wired to wireless adapters already exists and are pretty cheap.
https://www.amazon.com/Vonets-VAR11N-300-Mult … e/dp/B01199OGK0

An all-in-one card would be kinda cool though... but then you also have a greater chance of that one integrated thing to have something go wrong with it.

I actually was thinking about doing this also. Initially I was using a "wifi232" module I found which exposes an ethernet PHY, which I was coupling PHY to PHY on a salvaged PCMCIA card for testing. I had some issues and support from the company was not good on debugging the PHY. I purchased some tiny wifi/mini router things and I thought to use them, however it was just getting a bit too hackery and easier just to connect it to ethernet card and use a usb battery.

my thought is, with an esp8266 (or esp32) with 1mbaud to a uart, this would solve the retro modem/telnet bbs task, but also would be decent enough for basic network access, either via SLIP/PPP or what I was going to do is have a special mode to use with a network SHIM so I can get IPX frames on/off the network. 1mbaud is good enough for me.

for a desktop I think the ISA card makes even less sense in that case though, because it is so easy to just hook up external hardware and power supplies on desktops?

Working further on this, its now working with TCP/IP directly, no Terminal needed anymore.
PCB already drawn and i will soon show it !

For getting Desktops on WLAN i would purchase a WLAN Mini Router and run it in client mode, Wlan Router connects to WLAN and you connect it to your ISA Lan Card.

I am not sure I follow, what is your PCB, it is an PCMCIA card with an ESP8266?