08443: famicom: Most sets with "hvc_basic" slot do not start (grey screen)

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08443	Misc.	Major	Always	Oct 18, 2022, 17:20	Dec 20, 2022, 03:19

Tester	Firewave	View Status	Public	Platform	MAME (Official Binary)
Assigned To	AJR	Resolution	Fixed	OS	Windows 10/11 (64-bit)
Status [?]	Resolved			Driver	nintendo/nes.cpp
Version	0.248	Fixed in Version	0.251	Build	64-bit
		Fixed in Git Commit	57695dc	Github Pull Request #

Summary	08443: famicom: Most sets with "hvc_basic" slot do not start (grey screen)
Description	The sets do not start and only show a grey screen.
Steps To Reproduce
Additional Information	The affects sets are: famibs10 famibs20 famibs21 pboxbas1 pboxbas0
Github Commit

Flags
Regression Version
Affected Sets / Systems	famicom

Attached Files	famibs10.png (4,275 bytes) Oct 19, 2022, 04:38 Uploaded by Foxhack Family Basic v1.0 after selecting fc_keyboard

No.20615 Foxhack Tester Oct 19, 2022, 04:38 edited on: Oct 19, 2022, 04:38	You need to select the fc_keyboard in the EXP slot, then reset for it to start working.
No.20617 Firewave Senior Tester Oct 19, 2022, 06:47	<feature name="peripheral" value="fc_keyboard" /> So are you required to always supply the peripheral for such sets (also other systems) for them to work? Either way they should probably have a "usage" attribute detailing this like other sets have (e.g. ideyomj2): <info name="usage" value="This only works on a Famicom with Mahjong Controller attached"/>
No.20618 Foxhack Tester Oct 19, 2022, 07:32 edited on: Oct 19, 2022, 07:34	Well, yes, it's a cartridge that requires the Famicom Keyboard. You can't type in code or save / load to tape with the gamepad. "The first thing to know about any version of Family BASIC is that it will not work at all without a keyboard. If v1.0-v2.1A do not detect the keyboard, they will only show a black screen. v3.0 will just show a message essentially telling the user to plug in the keyboard. You should turn the Famicom off before plugging anything into or out of the Expansion Port." - From http://nerdlypleasures.blogspot.com/2021/03/family-basic-putting-computer-into.html MAME outputs a gray screen instead of black on Family Basic 1.0 to 2.1, so the behavior is correct, but I'm not sure if the color is or not. I tried finding some videos that showed what happens if you don't have a keyboard plugged in but couldn't find one. 3.0 correctly shows an error message if there's no keyboard plugged in.
No.20622 Firewave Senior Tester Oct 19, 2022, 07:52	> Well, yes, it's a cartridge that requires the Famicom Keyboard. You can't type in code or save / load to tape with the gamepad. I got that. That doesn't answer my general about "peripheral" features in general though. > MAME outputs a gray screen instead of black on Family Basic 1.0 to 2.1, so the behavior is correct, but I'm not sure if the color is or not. The grey screen is what is shown if you run the system without any cart so it is an indication that something isn't working right if you specify a cart.
No.20629 Foxhack Tester Oct 19, 2022, 18:27 edited on: Oct 19, 2022, 18:29	well yeah if it needs the keyboard to run it makes sense to have it plugged in automatically. I didn't know that was possible to do via the software list, though.
No.20638 kmg Senior Tester Oct 20, 2022, 04:59	The "peripheral" feature is just documentation at this point. There is a way to get software lists to load default peripherals (see "_default" sharedfeat tags in a2600.xml or sms.xml for some examples), but it won't work as is for nes.xml. The problem is the list is used by various NES clones that simply don't have expansion ports and hence all the related peripherals like the keyboard. In light of Foxhack's post maybe this is better called a BTANB and it should be a feature request. (Somewhat of a side topic, the color displayed is ok because it varies by machine, and then randomly, as it depends on palette RAM contents. MAME zeroes the RAM, giving the background palette color 0, i.e. grey.)
No.20639 Foxhack Tester Oct 20, 2022, 05:09 edited on: Oct 20, 2022, 05:11	Perhaps adding a "User notes" field in the NES software list file, like there is on the IBM ones? [info name="user_notes" value="Requires the Famicom Keyboard" /] Edit: Firewave mentioned a usage field, so that might be what should be used. I'm not very familiar with the software list's XML fields nor know exactly how they're supposed to work.
No.20969 kmg Senior Tester Dec 20, 2022, 03:19	AJR made the "_default" peripherals feature more robust, so these now autoload with a keyboard attached and boot properly. Rejoice! Thanks again Foxhack for pointing out the issue with these earlier revisions.