Subor Mouse

The Subor Mouse is a third party accessory, used not only by Subor themselves for their later educational cartridges, but also by a number of third-party titles by other developers. It responds to the same strobe signal as a standard controller, and the first eight bits returned are defined such that a standard controller's response will be that of a mouse that returns a movement amount of 1. As a result, the mouse pointer can be moved with a standard controller, and the movement of the Subor Mouse will be seen by non-mouse-aware programs as an equivalent standard controller response.

Input ($4016 write)

7  bit  0
---- ----
xxxx xxxS
        |
        +- Strobe

Output ($4016 or $4017 read)

7  bit  0
---- ----
xxxx xxxD
        |
        +- Serial data (bit 23->bit 22->...->bit 0)

24-bit response

222211111111110000000000
321098765432109876543210
------------------------
lrE.UDLR.XXXXXXX.YYYYYYY
||| |||| ||||||| +++++++- absolute amount of Y movement (0-127) if E=1
||| |||| +++++++--------- absolute amount of X movement (0-127) if E=1
||| |||+----------------- positive X movement detected (right)
||| ||+------------------ negative X movement detected (left)
||| |+------------------- positive Y movement detected (down)
||| +-------------------- negative Y movement detected (up)
||+---------------------- 1: movement amount greater than 1 or lesser than -1 detected, X/Y bits must be interpreted
|+----------------------- 1: right mouse button pressed
+------------------------ 1: left mouse button pressed

Notes

• GameStar Fun Educator꞉ 32-in-1 will only recognize mouse button presses if the E bit is set. This suggests that some models of the Subor Mouse may have that bit set all the time.