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I gather the original Macs used a serial port for the mouse with a RS-422 DE-9 connector. Totally nonstandard today. But surely, at some point some company (Apple?) must have made an adapter to use the early mice with USB-based Macs?

Thanks for any info...

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up vote 2 down vote accepted

As far as I know, the old mac mice used a DE-9 connector, but this isn't RS-232-compatible. If it was, you could have used an adaptor from RS-232 to PS/2 and then a standard ps/2-usb-converter (both must be active converters).

If you get an ADB-mouse you will be able to use them as there are adaptors for these.

If you're into electronics and programming, you could build your own converter eg. using a teensy-board for few bucks. It shouldn't be too hard as the old apple mouse just sends quadrature signals which should easily be translated into pointer movements.

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You could probably use the guts of a cheap USB ball (non-optical) mouse as a converter - just feed the quadrature signals from the Apple mouse to its decoders, tap its 5V power to run the Apple mouse, and you're set. Only problem I see is that the Apple mouse has TTL logic level outputs, and the USB mouse electronics might not cope with that. – Gordon Davisson Nov 5 '11 at 4:48

Normally it's an issue of drivers over converters. A quick search will present a plethora serial-to-USB converters for purchase. I simply wouldn't hold my breath on the system recognizing the input device.

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Old apple mice use DE-9 connectors but not RS-232-protocol. – Jens Erat Nov 4 '11 at 20:45

Yes. You will need a micro controller chip with both 5 digital I/O pins and a USB interface that can masquerade as an USB HID device. The Mac 128k mouse DE-9 connector has output pins for 2 XY quadrature encoders and the mouse button. Some micro-controller programming may be required.

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