MegaST v0.4.13 beta: function key and right mouse button fixes (restored hard disk not seen)

Pre-release for testing. Please report what works and what doesn't in the issues (core version, board, TOS, machine settings, disk image).

Fixed

• Function keys (#16): F6, F8 and F10 (Shift+F5/F7/F9 on the MEGA65) sometimes arrived as Shift+F6/F8/F10, so programs like GFA Basic reacted wrongly. The ST's keyboard processor could still see Shift in the moment the F key appeared; the F key now follows 20 ms later.
• Right mouse button (#17): the right button of an Atari mouse (or a mouSTer adapter) did nothing. It now works like the right button of the Amiga mouse. Please test with your mouse, and also check that a joystick in the mouse port does not act as a held right button.
• More timing margin for the HyperRAM clock on all boards.
• README: new guide Using disk images (floppy and hard disk step by step, FAQ). To unmount (eject) a drive, select its line in the menu and press Space.

Known problem

Some users report that a hard disk image is mounted but not seen by TOS since 0.4.12 (#11, #12), also after the core restored it at power-on. The same image boots in the simulator, so it is being investigated on real hardware. If a remembered image is not seen after power-on (#11): unmount it, reset and mount it again.

Files

Unchanged menu: the 99 byte atarist/stcfg and the 1536 byte atarist/stmount of 0.4.12 stay valid (stmount lets the core remember the mounted images, #13). Coming from 0.4.7 or older, copy the new atarist/stcfg from the zip, otherwise the settings are not saved. Hard disk images written with 0.4.10 or older may be damaged (#11): restore them from a backup.

File	Board	Status
MegaST-R6-v0.4.13.cor	MEGA65 R6	developer's board
MegaST-R5-v0.4.13.cor	MEGA65 R5	not tested yet, please report
MegaST-R4-v0.4.13.cor	MEGA65 R4	not tested yet, please report
MegaST-R3-v0.4.13.cor	MEGA65 R3/R3A (no SDRAM)	working on an R3A (#2); 512 KB ST RAM, no Viking, no STEroids

All changes: VERSIONS.md, manual: README.

MegaST is free and open source. If you enjoy it, you can support its development via GitHub Sponsors.