06864: cpc464 and clones: Graphic corruption when switching to 60Hz from software

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
06864	Graphics	Minor	Always	Feb 3, 2018, 07:02	Feb 23, 2018, 18:15

Tester	ICEknight	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS	Windows 10 (64-bit)
Status [?]	Acknowledged			Driver	amstrad/amstrad.cpp
Version	0.194	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	06864: cpc464 and clones: Graphic corruption when switching to 60Hz from software
Description	Enabling the 60Hz mode from an already running 50Hz instance makes some leftover graphics stay at the bottom of the screen, instead of changing the displayed vertical resolution.
Steps To Reproduce	Type the following line of code, then press enter: OUT &BC00,4:OUT &BD00,&1F:OUT &BC00,5:OUT &BD00,4:OUT &BC00,7:OUT &BD00,&1B
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	cpc464 and clones

Attached Files

No.14717 Tafoid Administrator Feb 3, 2018, 09:30	I'd like to see original hardware usage of this - do you have an actual machine? Is there a video detailing this with actual hardware?
No.14718 ICEknight Tester Feb 3, 2018, 10:15 edited on: Feb 3, 2018, 10:18	Just recorded this on real hardware and here's the result: I tried to edit my report to include the video and got an error message, by the way: APPLICATION ERROR #400 Database connection failed. Error received from database was #2002: Connection refused Please use the "Back" button in your web browser to return to the previous page. There you can correct whatever problems were identified in this error or select another action. You can also click an option from the menu bar to go directly to a new section.
No.14719 mahlemiut Developer Feb 3, 2018, 10:19	Currently, it appears that monitor resolution and refresh are set based the solder links on the PCB. This can be set in the Machine Configuration menu, so it might work better if that is set to 60Hz.
No.14720 Tafoid Administrator Feb 3, 2018, 10:20	So, your monitor is automatically adjusting to the new frequency after a time, or does it need to be manually told to adjust?
No.14721 ICEknight Tester Feb 3, 2018, 10:28 edited on: Feb 3, 2018, 10:28	I had to reach the CTM 644's V-Hold knob and manually adjust it myself. Also I have to note that the colors don't actually change as it may seem from the video, it's just the effect of recording the different refresh rates with the cell phone.
No.14727 Tafoid Administrator Feb 5, 2018, 06:06	I'll acknowledge this. Not sure if it will ever work outside of using the Machine Config switch ad mahemiut mentioned.
No.14774 ICEknight Tester Feb 23, 2018, 18:15	Just received an RGB cable for the CPC, testing results on a CRT TV are as follows: The picture adjusts itself automatically after the change, no need to touch anything. It also gets automatically stretched just like any game console does when switching resolutions. No garbage leftovers are kept on screen, unlike MAME's behavior.