Never seen that one, but if I had to guess, I'd say this is not for PCs but for the Amstrad CPC (a homecomputer)
The fact that you need a gender changer indicated that it's meant to be plugged into the old joystick-ports. I wouldn't stick that into a PC

In Amstrad PC1640 joystick port and attached directly without the adapter it generates mouse clicks. In mouse port, without the adapter, the computer refuses to boot stating keyboard or mouse error. With the adapter and connected to the mouse port (plus gender changer) it boots, the mouse pointer flickers after loading mouse.com and sometimes moves when pressing buttons.

With any luck the connector polarity and required voltage can be figured out from sharp hi res photos of both sides of the PCB inside. The ground plane is usually obvious, and the voltage can almost always be determined from the circuitry 😀

Found this...
http://blog.c128.net/archives/402
and this:
https://www.forum64.de/index.php?thread/33239 … r-wie-oder-was/
It seems to be a "Joystick Mouse"...

Its german but a translator should work. If you need something specific translated from german to english, just ask me.

Hi, thanks for the reference. I have opened up the box - the power connectors are electrically coupled and by tracing to a capacitor the centre is positive. Just like in the forum the board has writing MIDASONIC C64 INTER 767B, however I don't have a switch. From the forum it is also clear that the voltage should be 5V albeit it is not clear whether pc 1640 needs this power and whether I should even connect to it - it might be referring to amstrad CPC.

I have hooked it to power and connected to mouse port of pc 1640. On loading mouse.com the mouse cursor appears and rapidly drifts left, after a minute the computer reports stack overflow error and hangs.

With the power attached and connected to the joystick the computer doesn't boot and reports keyboard error.

It was perhaps a rather silly 'experiment'. The German forum mentions amstrad pc but I could not infer much.

Enness wrote on 2023-08-11, 17:26:

...
It was perhaps a rather silly 'experiment'. The German forum mentions amstrad pc but I could not infer much.

I think i found the part you are referring to ... They say that the Amstrad PC has a different pinout.

The 2 power jacks are ment for the Amstrad CPC where power comes from the monitor to the computer. You plug that in between the monitor and computer and extend it from the second port to the computer. Needed because Amstrad CPC has no Power on the joystick ports (the switch on the other version is for c64 mode wich has power on the joystick ports and doesnt need the 2 power jacks).

The links confirm what I wrote above: this is meant to be connected to the joystick-port and not the serial port. It converts the analog data of an analog mouse into joystick movement. That way you could use a mouse in any program that supports joysticks (we're talking about home computers - not PCs). Most programs did not support analog mice directly because they didn't even exist at that time or were not wide spread.

I would say any movement you get when connecting it to the serial port of a PC is more or less coincidental. I don't know about the Amstrad PC (not: CPC) but apparently it has two joystick ports. So in theory you could use it there - IF you had a mouse driver that converts joystick-movement into mouse-movement. Which I doubt exists 😀

Enness wrote on 2023-08-11, 17:26:

The German forum mentions amstrad pc but I could not infer much.

No, they mention the Amstrad CPC

I think you are right. Amstrad pc 1640 has a dedicated mouse port that is not a serial port (but there's a serial port for normal serial mouse and that works fine ctmouse.com driver) and a separate joystick port on the keyboard.

When connected to the joystick port with the adapter the buttons do register as mouse clicks but I do not see any codes from mouse movement (C program, getc routine, perhaps not low level enough).

I wonder if there's a driver somewhere for this 'joystick mouse'.

The would be an interesting experiment, but trust me - you don't want to use a 'joystick-mouse'. I have one for the C64 that directly sends these joystick-movement. It's horrible 😀 You have no acceleration, it's only up/down left/right with one speed

you are in luck, both Atari ST and amstrad pc 1640 (and Amiga, and Microsoft inport cards) use almost empty mice sending raw encoder signals to the computer .

Amstrad pinout https://www.seasip.info/AmstradXT/1512tech/section1.html
1 XA
2 XB
3 YA
4 YB
5 Spare
6 M1
7 +5 Volts DC
8 GROUND
9 M2

Atari ST https://old.pinouts.ru/InputCables/atari_st_j … ck_pinout.shtml
1 XB
2 XA
3 YA
4 YB
5 n/c
6 Left
7 VCC
8 GND
9 Right

looks like you should be able to plug Atari ST mouse without any converters directly into Amstrad PC mouse connector (afaik its in the keyboard?) and worst case moving left/right will be reversed.
Just make sure your Atari mouse is really an Atari ST mouse. Best to open it up and post a photo.

Great, it works as you described but with a different (original) atari st mouse (so I must have been delusional in the first post about the mouse type, not sure what happened!), the port is the one labelled "mouse", not on the keyboard. it appears that mouse.com which supports "inport" mouse doesn't have ability to reverse direction. Ctmouse can do this but doesn't support inport.

Shame that this nice looking mouse cannot be used for anything...

Enness wrote on 2023-08-11, 20:50:

Shame that this nice looking mouse cannot be used for anything...

Well, it can be used on an Atari ST.

Couldn't you just build an adapter that swaps the lines? Or swap the cables in the mouse?
Or sell the mouse to an Atari user and get a PC mouse? I've never seen this type so maybe some Atari-users would be glad to get it?