Hello! I was the guy that emulated the analog controls for this Taito game in Raine and then shared my code with the MAME team. This was way back in the year 2000, I even left a remark in my C code explaining that the Taito Japanese boards, had a strange and non-linear mathematics going on, to save 4 bits of RAM. A 1990's PC steering wheel or analog joystick for a flight simulator, when connected to a PC would physically inject a voltage, obtained by the joystick's potentiometer, into the PC Motherboard, which was converted into a digital value, ranged in the tens of thousands, and stored inside a Motherboard's adress. A 1990's PC game (either a DOS or Windows game) would scale down this voltage interval to -256,0,+256. So -256 is a steering wheel fully turned left on a 1999 PC game, while 0 is a centered steering wheel. But RAM memory was expensive in a 1988 japanese arcade board, the arcade hardware powering Chase H.Q. was very expensive, they had 2 dual MC68000 (Commodore Amiga) main CPU's and even had 2D hardware acceleration chips, to produce sprite zooming, the controls were handled by the Z80 (ZX Spectrum) cpu, which also controled the Yamaha sound chip. I figured out the mathematical algorithm for the analog steering wheel of Chase HQ, which only had 4-bit and 16 possible combinations: 8 values of the steering in a right turn + 8 values of the steering in a left turn. The problem was that the japanese spread and hid those 4 bits all around the Z80 cpu's memory, and they were not consecutive. Example: A Taito XXXXXXXX 8-bit adress, where bit 1 is part of the steering wheel value, but then bit 2 is the number of deposited coins, bit 3 is something un-related, and then bit 4 is also part of of the steering wheel value. The trick I used: 1) I used the RAINE emulator code, and added a line to inject the values of my PC analog joystick, directly into the emulated japanese machine RAM adresseses, while aslo displayng those adresses on the video game. I started the emulator with Chase HQ. 2) I turned my joystick untill the porsche's braking lights turned on! Woohoo! The break pedal is around this range of adress! 3) Eventually I figured out in what order the 4 bits of the steering wheel, must be read, to produce the +8,0-8 possible Chase HQ's steering wheel position. 4) It was the same strange order used in Special Criminal Investigation, and I submited the code to MAME also. 5) I also did a similar job in Sega's Afterburner game, for the analog Z-Axis speed throttle and joystick. I hope you enjoyed my nerdy insight, I was feeling nostalgic and decided to share this. I'm not very good at programming, I could only help in minor details such as the controls, because I studied Electrical Engineering. Please comment or leave a like. :)
@@sasapetroski981 I'm a bit older, and loved Chase HQ. What I was saying is that in 1989 (still the 1980's decade) the sequelk was released, and it was a better game, with bazookas, guns, helicopters, oncomming traffic, animations of a van with criminals throwing cannisters, etc. It elevated the original Chase HQ to a whole new level, still in the 1980's decade. In the 1990's I could finish both arcade games with 1 single coin, and people would gather around me, to watch the games beeing finished with 1 coin. I was a fanatic! :)
First time ever I've read the instructions @ 1:22 " Your mission is to catch up criminals, bumb into them..." "The distance between you and the climinal..." Nice Engrish there Taito.
Lhes apresento o primeiro Burnout na plataforma 60fps dos anos 80 Não existe trabalho mais fluído do q essa obra de arte e ainda tem o áudio e a dublagem, espetaculares!
I love this chase game very much. I remember played it 30 yrs ago, last section i have 28 seconds left after finishing. I personally think It is a new record.
Let's go Mr. Driver. Then drop the clutch in a black 928. I wonder why it's my #1 game. I was lucky to own a gold 81 928 like in risky business. Love at first sight
I was watching vids of terrible ports of this game, so had to remind myself of the arcade original! Wow, look at it go! fast, smooth graphics- the only issue is that it could affect epileptics! Lots of really good quality speech for an 80s game!
I'm a big fan of your videos and a subscriber. I like to make Live Streams of classic games and provide a history and strategy commentary during the gameplay. I normally play my own games but for a game such as this that I do not own, is it okay if I use the gameplay from this video while I provide my commentary? I will gladly provide a link to this video and mention to subscribe to you. Thanks!
![Chase H.Q. Longplay (Arcade) [4K]](/img/logo.svg){kind=logo}
