Sega Mouse on Amiga?

[Lakanman]

Anyone know if the Sega Mouse works on Amiga?

[lilalurl]

Can't answer you, but as I had no idea it existed before you posted this, I looked a bit online.

I found a forum post that might be useful for people with enough technical knowledge to tell you how likely it is to be compatible:
http://gendev.spritesmind.net/forum/...7dad7105f93d2c

Charles MacDonalds doc on the Genesis IO, where you find this:


Sega Mega Mouse

This is a three button mouse (left, middle, right) with an extra button (Start) located near the thumb position. It uses a PIC16C54
microcontroller which manages the buttons and position tracking.
The Sega Mega Mouse that is distributed in North America is incompatible with the European version of Populous 2. The mouse
functions normally but has Y axis inverted so up is down and vice-versa. It may have been designed for the Japanese Mega Drive
mouse, which is a different product with 2 buttons and unique physical appearance.
The protocol works as follows: TH and TR are outputs which tell the microcontroller to stop or start a data transfer, and to
acknowledge received data. TL is an input which returns a busy flag for the microcontroller. D3-D0 are inputs that return the data.

Here's a table showing the communication process:
Write TH TR TL D3 D2 D1 D0 Description
$60 1 1 1 0 0 0 0 Request data
$20 0 1 1 0 0 0 0 ID #0 ($0)
$00 0 0 1 1 0 1 1 ID #1 ($B)
$20 0 1 0 1 1 1 1 ID #2 ($F)
$00 0 0 1 1 1 1 1 ID #3 ($F)
$20 0 1 0 Y Over X Over Y Sign X Sign Axis sign and overflow
$00 0 0 1 Start Middle Right Left Button state
$20 0 1 0 X7 X6 X5 X4 X axis MSN
$00 0 0 1 X3 X2 X1 X0 X axis LSN
$20 0 1 0 Y7 Y6 Y5 Y4 Y axis MSN
$00 0 0 1 Y3 Y2 Y1 Y0 Y axis LSN

Write #$60 when you are done polling to stop the data transfer. If you continue to poll the mouse after collecting all the data by
writing $20 / $00, the Y axis LSN will always be returned. Sega advises polling beyond this point will make the mouse behave
abnormally. It's possible that the PIC code in some versions of the Mega Mouse may have problems if the poll sequence is too
long.
The X/Y overflow flags are supposed to be set if the mouse is moved over a distance greater than can be measured. I can't get
them to become set, maybe the mouse supports a fairly wide range of movement.
You need a considerable delay between writing new values to TH/TR. I think the intention is to poll TL until the microcontroller
returns 'not busy', but I can't get this to work reliably. Sega's mouse reading code also has a timeout when checking TL which
would indicate it may get stuck in a certain state.
All buttons (start, left, middle, right) are active-high logic, so they return '1' when pressed and '0' when released.

[robinsonb5]

Originally Posted by lilalurl

I found a forum post that might be useful for people with enough technical knowledge to tell you how likely it is to be compatible:

Interesting! It's definitely not compatible out-of-the-box, but with the "standard" MegaDrive to Amiga wiring adapter, it may be possible to read the mouse, given the right driver software.

If you're hoping to just plug it in and go, though, there's no chance.