Mouse pointer movement stutters while formatting ADF in any drive

[Fishdieb]

Setup: MiSTer 32MB, heat sink, HDMI output, Mouse and keyboard connected with passive hub Minimig: v200701 MiSTer: v200907

Steps how to reproduce:

• Create a configuration A500 with kickstart 1.3, 512kb chip, 512kb slow RAM
• Floppy turbo set to off
• Insert Workbench ADF into drive df0: and load the workbench
• Insert a blank ADF into drive df1:
• Select "Initialize" from workbench menu and start formatting df1:
• While formatting, move mouse pointer - it stutters
• At around track 20 open up the MiSTer menu. After some seconds the lower text "<- exit ->" will be replaced by the usually smooth scrolling line showing "Welcome to MiSTer! Use the cursor keys to ... ". Also this scrolling stutters heavily - it feels like the whole system runs at limits.

Once the formatting was done, text and mouse pointer are back to normal.

The same happens also with kickstart 3.1 and workbench 3.1- no difference. I also tested: Minimig_20200423 and Minimig_20200629 - same issue there. Usually the mouse movement is fine - even while reading data from ADFs. It also happens if using drive df0: to format a disk.

Right now I have the same issue while copying files from dh1: to dh0: ... So it might not only related to write operations on ADFs - maybe it's the SD card?

Does anybody else has this issue?

[rsn8887]

This happens to me anytime something is loading while moving the mouse.

I always thought this is because mouse motion data are passed from Linux to the Minimig core over the same serial communication channel as adf and hard disk data. If there are lots of data going through that channel, maybe there's a buffer overrun or underrun or the channel is saturated in some other way.

At some point I bought a low-resolution mouse and it made the pointer more smooth, I think because it had a lower data rate and therefore didn't clutter that linux<->fpga channel so much. But since then I switched back to my regular mouse out of laziness.

[werdy77]

Have similar issue with the latest (_Minimig20240912.rbf) version when IDE is more active, eg. opening Prefs folder and loading icons in higher resolution/depth (RTG).

[sorgelig]

Probably it will be hard to fix because IDE may occupy whole time when data is actively transferred, so no time for mouse data left..