02932: tutankhm, tutankhms: Background stars missing in attract mode

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
02932	Graphics	Minor	Always	Feb 19, 2009, 19:17	May 10, 2019, 16:29

Tester	mcp	View Status	Public	Platform
Assigned To	couriersud	Resolution	Fixed	OS
Status [?]	Resolved			Driver	konami/tutankhm.cpp
Version	0.129	Fixed in Version	0.210	Build
		Fixed in Git Commit		Github Pull Request #

Summary	02932: tutankhm, tutankhms: Background stars missing in attract mode
Description	background stars missing in attract mode of TUTANKHAM. while showing title TUTANKHAM and high score list there are stars blinking in various colors in the background.
Steps To Reproduce	I have compared the original PCB of Konami in my arcade game cabinet, there are always background stars while in attract mode.
Additional Information
Github Commit

Flags	Verified with Original
Regression Version
Affected Sets / Systems	tutankhm, tutankhms

Attached Files	tut_backgstars_1.jpg (45,160 bytes) Feb 20, 2009, 10:21
Attached Files	tut_backgstars_2.jpg (45,724 bytes) Feb 20, 2009, 10:21

No.03757 Tafoid Administrator Feb 19, 2009, 20:10	Simply telling us there is a problem with a game is not enough proof that there is a bug. We need screenshots, video captures or other evidence (especially that it's graphic issue you are reporting) - this must be backed up with these visual options. There is the possibility that your PCB is a bootleg based on Galaxian Hardware. There have been such bootlegs in the past in which a starfield could show up during use. I would suggest to you to assure that your PCB dumps match that of current MAME romsets. If not, you might have another version/bootleg which could be added and properly supported. Unfortunately, until we get some tangible visual information from you, we cannot continue with this report. I will correct the fields and acknowledge the report for now.
No.03763 mcp Tester Feb 20, 2009, 09:20 edited on: Feb 20, 2009, 10:25	The PCB is original Konami (Stern), all the ROMs match the MAME romset (J1-J9, H1-H6, 7A, 8A). The PCB is the typical Konami layout used in the 80s and to be exactly sure I have comapred it to the one pictured on www.progettoemma.net which shows the original Konami/Stern PCB. One more thing about the background stars: they are not moving or floating ( like in Galaga ), they are appearing / vanishing in random order, which, btw, looks pretty good and gives the attract mode some mystery touch. Another note: The background stars do not appear in the "Press Start One Player Only" screen. See the (ugly) screenshots I made today.
No.03764 Tafoid Administrator Feb 20, 2009, 15:13	Those screenshots show the issue well. Thanks for further describing the stars' behavior. Confirming and adjusting the set to include the Stern version.
No.03869 couriersud Developer Mar 1, 2009, 15:27 edited on: Mar 1, 2009, 15:28	The schematics support a starfield as well. It is most likely generated by a custom (cough, cough) IC labeled "084" at position F3. It does not look like a prom (24 pin, pin 18 is output), so may be a gal. It should be readable thought: Inputs: 1-8,10,11,20-23 Outputs 13 - 18 Pin 19 seems to be output as well.
No.05962 mcp Tester Apr 12, 2010, 15:44	@couriersud is there anywhere described how to read out the mentioned gal at position F3 ? if so, I could try it with my boards, but need help on how to do this.
No.06103 hap Developer May 12, 2010, 18:07	"they are not moving or floating ( like in Galaga ), they are appearing / vanishing in random order" Sounds similar to Konami's Scramble. "The background stars do not appear in the "Press Start One Player Only" screen." Are you certain? I'm pretty sure the starfield enable/disable bit is at $8204 (you don't need to understand that :P). Thing is, according to that, it's still enabled at the press start screen after you insert a coin. It's only disabled at the playfield.
No.06109 couriersud Developer May 13, 2010, 12:44	Some information about konami custom chips and replacements can be found at: http://www.fpgaarcade.com/konami_customs.html Here's some information from the schematics about the input and outputs of the 084 [code] Inputs: NE555 ==> 10 (approx 1 HZ) 401 ==> 1 (crystal clock, most likely around 6 MHz) 109 ==> 2 (Video related) 403 ==> 3 (Video related) 403 ==> 4 (Video related) 405 ==> 5 (Video related) 406 ==> 6 (Video related) 420 ==> 20 (Video related) 421 ==> 21 (Video related) 422 ==> 22 (Video related) 423 ==> 23 (Video horizontal signal H1) 0x8206 HFF ==> 7 (Horizontal flip) 0x8204 407 ==> 8 (Enable ???) Outputs: 13 Red 14 Red 15 Green 16 Green 17 Blue 18 Blue [/code] Simply reading it out is not possible. It looks more like it contains some random logic (rng-type) to generate the starfield. The "video related signals" are all video control signals (e.g. hblank, vblank ...) fed into the chip.
No.06118 mcp Tester May 15, 2010, 16:02	@hap: "Are you certain? I'm pretty sure the starfield enable/disable bit is at $8204 (you don't need to understand that :P). " I have checked back for the background stars in the "Press Start One Player Only" screen with my Stern Tutankham board and found out that they appear as well as do not appear, it simply depends on whether or not the stars were visible in the moment a coin is inserted, so the byte at $8204 is not reset by the coin insertion. Btw, I understand the $8204 stuff very clearly - I was programming 6502, 6510 and 68000 in machine language for years - I also did a Tutankham and Roc'n Rope game for Commodore 64 and sold them here in Europe. Man, these were times, I loved programming the 6510 although it was hard coding in LDA, STA, STX and the like .....
No.06119 hap Developer May 15, 2010, 17:43	Thanks for checking again =) Your description is consistent with $8204 in MAME.
No.16068 MetalGod Senior Tester Jan 22, 2019, 23:08	Here's a pcb video: