In fact, the package arrived in my mail on the very Christmas Eve, which was a perfect timing and a great Christmas gift to myself!

It was claimed to be working the last time it was tested (probably in the late 90's) by the seller, but it was missing the bottom side plate and the cable, cd's, manuals, packaging etc. The PCB inside was literally just floating around inside the case loose!

Since I'm working on the last bits of a very long movie planned for YouTube in 2024 ("The hunt for my Amiga CD32"), this item arrived as a perfect addition to that story.

Upon first inspection:
1: 3D-Print a new bottom plate.
2: Replace the RJ11 telephone connector (it was very loose, suspect broken)
3: Replace the sticker, as it's very scratched.
4: LEDS (MIDI Receive (Yellow), CD32 SEND (Green), HOST SEND (Red) are extremely faint. Wrong resistor or worn out LEDs due to wrong resistor in the first place? Noticed during quick testing of MIDI signals and pushing a file through the serial port with send file.
5: There is no power LED - who the fuck designed this, you always need a power LED for god sakes!
6: Sloppy-ass designed PS2/AUX Connector functionality (stupid and easily broken).

I have added some bonus material at the end of this post (downloadable material) to document this device better than has already been documented out there on internet, like High-Res Scans of both sides of the PCB and the 1:1 re-creation of the original label).

I have also dug out PDF (reviews) of the Eureka Communicator II / III using my very own Search Engine to document the history of this device. The PDF's was added in the links at bottom of page.

Note: In my own scripts I made back in 1994 after RAD: was mounted:

rad:c/loadwb

rad:c/Echo "Autobooting TWIN EXPRESSWorkbench is also loaded"

rad:c/echo "TWIN: Using baudrate at 190000bps!!!"

rad:c/dir ram:

rad:c/winsize 0 30 640 220

rad:Twin SER 190000

I most likely used this as max speed. However, if the readme's I have come across, it says that Twin Express with only 3-wire should be able to do 210000bps max. As I have not yet figured out the pinning of RJ11 nor the DB25 side on the Amiga connector this is still a mystery.

It was mentioned on forums on internet that they thought the Communicator Serial Transfers were slow. Now 190000/8 = 23750 bytes pr second, or 23.7kb per second. If the max speed was really 210000/8 = 26250 bytes pr. second or 26.2kb per second, for a 1MB (10000000 bits / 210000 bps) file it would take 47 seconds to transfer. To be honest, is that really slow when you think about its 1994?

So ChatGPT says:
In 1994, transferring a 1 MB file in 47 seconds would have been impressively fast. For comparison:

Dial-up users would need ~5-10 minutes for the same file.
Your transfer speed at 210 kbps would have been a high-end capability at that time!

ChatGPT also says that those speeds we wrote above as max serial transfer speed where actually slightly faster than the Amiga floppy drive reading the same amount of data.

So, either those folks online thought that was slow in those years which means 1 out of 3 things:
1: They could not have tried speeds like these, but more like 9600, 19200 bps. Meaning they did not know about RS-232 speeds, bps, Twin Express and so fourth. Did they ever read the readme's? Did they really boot the Communicator CD which gave them options to choose from? It ranged from "TWIN SER 57600" to "TWIN SER 290000". Where they dumb enough to choose the 57600bps? Really, and you got yourself a Communicator for what purpose exactly?

2: They compare those speeds in 1994 with the expectations and observations of todays technology, which of course if way off.

3: They had extremely low patience, which should not be possible in 1994, as if you where a true retro fan in the 80's, you would load C64 Tape Games, and such speeds as 26kb pr. second on an Amiga to Amiga transfer would literally blow your mind.

To be honest, my memories from that era, using Amiga CD32 + Communicator connected to an Amiga 1200 felt all perfectly fine and not horror-slow compared to have lived through the C64 tape loading period myself.

In fact, in 1991 or 1992, I tried a 300bps modem for the first time - and yes, that felt awfully slow. I later upgraded to 1200bps modem, but yet again, it took forever to download an Deluxe Paint iff file of 20kb or so, we are talking 30minutes most likely.




With the 3-wire connection as shown in the end of this article, I successfully managed to get Serial connection running between Amiga 1200 and Communicator+CD32.

Transfer speeds tested:
1000000 (1mb) file on 210000 baud = 52 seconds
1000000 (1mb) file on 230000 baud = 49 seconds
1000000 (1mb) file on 250000 baud = Partial, but classified as not stable.

So, safe side 210000 baud is as advertised for the Communicator, allthough I ran a full 1mb file even a 230000 baud.

This means that the speed I had in my own scripts in 1994 was really the highest and stable I could even get back then at only 190000? Maybe my cable back then were crap, or could even be interference. Glad I could re-confirm this with my new cable tested a whopping 30 years later at max 230000 :-)