Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
07685 DIP/Input Minor Always Jun 12, 2020, 09:42 Jul 13, 2020, 02:50
Tester oboewan42 View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Windows 10 (64-bit)
Status [?] Confirmed Driver
Version 0.221 Fixed in Version Build 64-bit
Summary 07685: sonic, cabalus, possibly others using upd4701a: mapping joystick to trackball causes input to go haywire
Description Moving an analog joystick axis that's mapped to a trackball axis - specifically one connected to a uPD4701A - causes the input to go haywire, even when sensitivity is set to 1. Mouse input appears to work fine.
Steps To Reproduce Map an analog stick to a trackball (MAME is set up this way by default if you have a controller with an analog stick), then move the stick and watch the analog controls go haywire. Visible in-game, in the test menu in sonic, and in the "Analog Controls" menu. Compare with version 0.185.
Additional Information I vaguely remembered being able to play SegaSonic perfectly fine with an analog stick in an older version of MAME, so I checked for a regression. Last working version was 0.185, it broke in 0.186. Looking in the whatsnew it looks like there was a rewrite of the code for the uPD4701A around that time.

Tested in sonic and cabalus, both exhibit this issue, haven't had a chance to look at anything else (what other games use it?)
Centipede works fine, so it seems to be limited to that chip.
Regression Version 0.186
Affected Sets / Systems sonic, cabalus, possibly others using upd4701a
Attached Files
There are no relationship linked to this issue.
User avatar
Jun 14, 2020, 19:00
I don't have a decent non-mouse analog device to use for testing at this time, but I've acknowledged for now.
User avatar
Jun 18, 2020, 17:47
This may be a problem with not accounting for PORT_RESET, which the uPD4701 emulation now depends on.

Other sets to test include arknoid2, ridleofp and simpbowl.
User avatar
Jun 18, 2020, 19:10
arknoid2 and ridleofp have the same issue (did not test simpbowl)