Re: [新聞] (WIP) David Haywood's Homepage
2016.02.27
"Not Letting Go"
When a game shares a name with a different but much better known game it can
prove tricky to track down, and, in cases where nothing is known other than
the title it’s difficult to know if you’re looking for an original game, a
license, or a bootleg.
Philko’s Lock On is one such game, sharing it’s name with the still rather
obscure, but better known (in part due to emulation) Tatsumi game from 1986.
Until yesterday we didn’t really know what to expect from this game, but
completely out of the blue a user called ‘marcus’ dumped a PCB for it and
submitted it for us to emulate.
There are a few Philko games in MAME already, a couple of shooters running on
hardware that was cloned from Side Arms (Whizz / Dyger / Turtle Ship) and
some simple puzzle style games on a sprite-less System 16 hardware clone
(Atomic Point and Snapper)
Looking at the PCB / roms the hardware here didn’t quite fit either of those
profiles, it was 68k based, so no the sidearms derived hardware, but it also
had sprite roms, so it wasn’t identical hardware to the System 16 titles,
also it had an OKI M6295 in sound section which none of those have either.
The sprite roms were clearly non-tile based, and looked clearly like Sega
System 16 format sprites, so the first and most logical route to explore was
that this was a more complete clone of Sega System 16 hardware than used by
the other Philko titles. There were a couple of issues with this assumption,
first of all, the tile roms were clearly 4 bits per pixel graphics whereas
the original System 16 hardware and Philko clones were all 3bpp. (In English
this had 16-colour per tile, not 8-colours per tile)
Either way, I quickly hooked it up in the System 16 driver, and it booted,
even showing me some sprites, the assumption WAS correct, however it would
need further work, Philko had made significant changes to the hardware while
copying it. It was immediately obvious that the palette RAM was bigger,
again, fitting with what had previously been observed, if you have 16 colours
per tile then you need more colours in total. Oddly, even with that all set
up, and the base of the sprite palettes adjusted accordingly the colours were
still off. It turned out that palette format had also been changed here, from
the xRGBRRRRGGGGBBBB format of the original hardware to a simpler
xBBBBBGGGGGRRRRR (where each R/G/B letter represents a single colour bit)
Adding support for that alt format fixed the colours.
Sound was also different, I used the emulation from Whizz as a base, because
clearly, from observing the reads / writes that’s what Philko had done, but
here there was also an extra port used to access the OKI M6295 sample
playback chip. As none of the clocks were measured on the PCB, nor the
divider pin for the OKIM6295 I’m not 100% sure the sound is perfect.
With all that hooked up, inputs sorted out, and dipswitches deciphered to a
usable level the game was playable. It seems like it was heavily influenced
by Capcom’s US Navy / Area 88.
Interestingly the game doesn’t show a copyright on the title screen, but
there’s a Philko disclaimer on the startup, Philko tiles in the tile ROMs,
and a 1991 date on the bottom of the high score table, one of the dipswitches
flips between ‘Korea’ and ‘Europe regions. Philko was also one of the few
Korean manufacturers to actually have their own marked custom chips too
(albeit only one of them on this PCB, the others had generic markings)
Also of interest is that the game does attempt to program what appears to be
a clone of the Sega memory mapper chip (used for dynamic memory maps on
System 16 etc.) although I haven’t currently hooked it up as dynamic, might
have to see if it really does program valid values tho.
Again Big thanks to marcusfor dumping his PCB here. The picture provided
alongside the ROMs is shown below.
http://mamedev.emulab.it/haze/pics2016/lockonpcb.jpg
I’ve also uploaded a video below, you can see some minor clipping issues on
the left side in attract, but I’m 99% sure those will happen on a PCB too,
the image it’s scrolling around is part of one of the tile layers and simply
isn’t wide enough to cover the area where you can see the blank space.
https://www.youtube.com/watch?v=6NpyGXJT5IE&feature=player_embedded
來源 http://mamedev.emulab.it/haze/
此外...
This is pretty much the biggest fundraiser we have ever tried in terms of
money. Firstly here are the (really interesting) games:
http://mamedev.emulab.it/undumped/index.php?title=Hangzo
http://mamedev.emulab.it/undumped/index....uka_Bakugekitai
Shoutime had to pull the trigger quickly without much thought or else a
collector would have gotten them and then they'd never go in MAME, and
together they cost $13,000. Yeah. So we don't need to cover it all but if we
set a realistic(?) goal of 40% (~$5,000) of what he paid then he can dump
them and basically take a loss on the rest. So, who can help us? Send me a
private message to make a pledge/donation or just click below and I'll
forward the money to Shoutime. You can send money to him directly instead if
you want but his paypal email is not public so you will need to get it from
me in a private message.
https://www.paypal.com/cgi-bin/webscr?cm...tton_id=4680820
Thanks so far for pledges and donations from:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=4680820
Imhotep
Ryan Holtz
hap
Zhivko Dimitrov
spogghi
ANY
Arjen Hoekman
Arcade Addict
krick
Dullaron
Eddie
f205v
rtw
Rod_Wod
Fabien Marsaud
InsertMoreCoins
Jan Stuhler
trap15
Macaw
Team Japump
Notes: There will be delays in the donor list updates because they are coming
from multiple sources. We are expecting this fundraiser to take at least 2
months.
http://www.mameworld.info/ubbthreads/userfiles/350790-image1.jpg
來源 http://www.mameworld.info/ubbthreads/showthreaded.php?Cat=&Number=350790
&page=0&view=expanded&sb=5&o=&fpart=1&vc=1
http://tinyurl.com/zg7rpwo
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※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 118.160.65.238
※ 文章網址: https://www.ptt.cc/bbs/Emulator/M.1456753452.A.253.html
※ 編輯: conpo (118.160.65.238), 02/29/2016 21:49:16
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