Monday, July 02, 2018

CannonBall Interview [OutRun Week on Scarflix!]

Youtube channel Scarflix are hosting a week of awesome OutRun related content!

There's even an interview with an awkward British guy, talking about CannonBall...

Also check out:

Top 5 Things You Didn't Know about OutRun

Tuesday, June 12, 2018

The Insanity of Sega Super Circuit (セガスーパーサーキット)

I’ve always had a strange fascination with Sega Super Circuit (SSC). SSC was conceived and developed by Sega’s Mechatronics R&D department, and it went through a series of iterations between 1987 and 1990. It was a bold attempt to combine multiplayer arcade racing with real world remote controlled cars. Visitors to venues including Sega World, Tokyo could watch up to 6 RC cars whizzing around a track, set in a futuristic city, that when unravelled was 103 metres long. 

The track itself took up a total floorspace width of 20 metres, with each section between 1.5 and 2 metres wide. This was not an attraction that would fit in your typical arcade! 

The 6 participants raced an RC vehicle, controlled from a converted OutRun deluxe cabinet. The 26 inch cabinet monitors relayed video footage from the CCD camera onboard each RC car. The cabinet’s controls were mapped to the RC’s controls, allowing players to steer, accelerate, brake and reverse. The cabinet’s motion would even kick in during collisions and whilst steering. The advertising boasted that the sense of speed was close to 300 km/h when playing. 

The RC cars themselves were relatively compact: 16cm by 35cm and weighing in at 1.9kg including the battery. 

SSC was hosted by a live commentator, with a dedicated team required to keep the attraction running successfully. In many ways the concept has parallels to a modern e-sport competition, with the added advantage of something physical for spectators to enjoy. 

Best race times, lap times and general champion ranking were displayed in leaderboards by the course. 

There was also a bank of 6 external monitors for on board views of the action.

An operator control room, situated in the middle of the track housed a set of 10 inch screens to monitor the race. From here, it was possible to configure endurance races, (apparently including “Le Mans 24 hours” and “Indianapolis 500”) as well as sprint races. Exactly how these worked is unclear. The races themselves look somewhat chaotic from the surviving video footage. Reports from those lucky enough to try the exhibit first-hand, claim it was rather difficult to even drive straight! 

What impresses me the most about SSC, is its scale and ambition. It's a manifestation of Sega at the height of their arcade powers. The footage shows that the camera feed from the RC cars is imperfect and prone to breaking up; Sega were clearly pushing the limits of late 80s technology.  It must have been a complex operation to run logistically and it’s hard to imagine arcade operators beyond Sega having the space or resources to maintain such a complex attraction. It must have cost a fortune to design, construct and operate.

  • July 1987 - Sega Super Circuit (then known as ‘Super Game Z’ and a joint venture with Nissan) was first demonstrated at Communication Carnival Yume Koujou '87 [youtube]
  • 1988 - SSC is officially named and demonstrated at the 88 Amusement Machine Show [youtube]
  • 1989 - SSC exhibited at YES '89 Yokohama Expo [youtube]
  • 1989 - SSC transferred to Sega World, Tokyo Roof
  • 1990 - Last known operational date


The configuration of SSC varied dependent on the venue. This included changes to the number of cars on track, through to changes to the track design. The earliest version, featured different car designs, a minature roller coaster and giant monster prop


I recently managed to purchase the original flyer for the attraction. It wasn’t easy to find and there were no high quality scans online, and so finally here they are! Please link back to this blog if you make use of them. High quality versions here.

Tuesday, May 22, 2018

Play OutRun on the Nintendo Switch via CannonBall

CannonBall was recently ported to the Nintendo Switch console by Modern Vintage Gaming. Hoorah, OutRun everywhere! 

Github Repository here

Wednesday, March 21, 2018

The Space Harrier prototype featuring a Harrier Jet!

It's common knowledge that Space Harrier was originally intended to feature a harrier jet. However, technical limitations regarding the rotation of the jet sprite meant that this idea was dropped late into development. Recently, some screen captures surfaced from a video showing the prototype machine in action at the Amusement Show in Japan. 

The side-art and marquee are different. However, the colour palette and general aesthetic appear similar in the screenshots. 

The above cabinet design is similar to the prototype drawing that appears in Yu Suzuki's GameWorks Vol 1.

Of course, it was too late to change all aspects of the design, and Space Harrier still launched with an aircraft inspired control panel. The jet idea was fully realized two years and two hardware cycles later when Sega released the X-Board hardware with AfterBurner. Custom maths hardware, and extra sprite data enabled Yu Suzuki's original vision to be executed competently by this point. 

Sources: 1, 2 

Tuesday, February 06, 2018

Build Your Own OutRun Cab: Dorimaga Papercraft Model

Following on from the Space Harrier model, I've (finally) scanned the the September 2004 issue of Dorimaga magazine.

This includes Sega History Papercraft Vol 3, a constructable model of the deluxe sitdown OutRun Cabinet. How cool is that?

If you have any issues in the series, please let me know.

High resolution scans here.

Thursday, January 18, 2018

Build your own Space Harrier cab: Dorimaga papercraft model

Thanks to Sean Tagg for scanning the Space Harrier papercraft model included with Dorimaga magazine.

Sean mentions, "I enlarged the sheet to A3 and laminated it. I have used this to then make a model from balsa wood. The screen is a photo keychain. The seat is fabric too! Just need to add the coin tower."

Here's the finished article, now with coin tower:

Finally, a link to the scan if you want to build one yourself.

...and yes, I need to scan my Dorimaga OutRun magazine at some point soon. I've misplaced it for the time being, but it will show up somewhere! 

Sunday, December 17, 2017

2 x Power Drift PCB Repairs

I'd accumulated 4 broken or untested Power Drift PCBs. All four completely black-screened and showed no signs of life. I decided it was time to try to get at least one of them working. They are difficult boards to find working and I've always fancied playing the game in my OutRun cab.

Board 1 (The Easier Repair)

The Y-Board is complicated, using 3 68k processors, a z80 for sound and loads of custom chips. So when faced with a dead board, there are a lot of potential candidates. Using the scope, I could see the main 68K CPU was resetting every few seconds. There seemed to be good activity on the data and address lines however.

I tested the Main CPU EPROMs first and they all seemed to be bad?! To be honest, I don't know how much I trust the GQ-4X with 27C1000 EPROMs.... it seems inconsistent. But anyway, all the NEC D27C1000 branded ones failed romident. I programmed some new ones, and pinched a few others from one of the other spare PCBs.

The board then booted into life, but with lots of graphical corruption. Amazing - I've never had such an easy fix before. However, the game completely crashed after a short period of time.

Using the scope again I could see that the 'Sub X' CPU (Mame driver naming) had no activity on the data or address bus. The 'Sub Y' CPU seemed to be behaving sensibly. At this point I replaced ALL the NEC branding EPROMs for both CPUs.

The game then ran consistently without crashing, however there were occasional graphical errors.

I swapped the lower video PCB out with one of the other spares and this solved the remaining graphical issues. Unfortunately it was quite late at this point and I forgot to take photos of my progress.

So there you go - not really the most technical fix-log ever. But a fix is a fix, and I'll have a poke around the remaining 2 PCBs next. I also need to hook up some controls.

Board 2

Now that I had a fully working boardset from the previous repair it was easy to establish that I had 3 broken CPU boards and 3 partially working video boards with graphical errors remaining.

Picture shows the CPU board (courtesy of

The CPU Board contains 3 x 68000 processors. These and known as the main CPU, X CPU and Y CPU. I initially investigated the main CPU signals and bus with my scope. I verified the EPROMs, then checked the SRAMs and buffer logic chips to ensure they were doing something sane. The PCB itself was filthy. Amusingly, pretty much every EPROM I pulled had a dead spider under it. One of them actually made me jump as it flew out at me with the chip! I was finding physical bugs, but no technical bugs, so it was time to move on!

I moved onto the X CPU. After working my way around the chips in the circuit I found little activity on the SRAM data and address lines. I piggybacked the first pair of SRAMs at IC 84 and IC 85, and to my delight the board booted. At this stage there were no zoomed sprites at all and lots of graphical errors. Only some of the static 2D sprites displayed correctly. However, I could coin up and hear sound and music which proved  the main 68000 circuit and Z80 sound circuit were healthy.

I put the board into test mode. Things weren't completely readable but the screen could at least be compared with MAME. The tests reported 4 SRAMs and 2 EPROMs were bad in the X CPU circuit. However, this report couldn't be fully trusted at this stage due to the piggybacked RAMs. I tested the EPROMs that were reported bad and found them to fine to prove this point.

I socked two replacement 6164 SRAMs at IC 84 and IC 85.

 I tested the old ones out of circuit and found them both to be faulty.

I booted the board again to verify the replacements were working. I then decided to piggyback the remaining two SRAMs that were also reported faulty by the internal tests at IC 82 and IC 83. They were right next to the previous bad ones and also similar Toshibas, so could in theory be bad as well. At this point I managed to see glimpses of the zoomed and rotated sprites that make up the game's road layer and backgrounds. The rotating Power Drift logo also showed signs of working.

After replacing IC 82 and IC 83, the game was running with scaled sprites.

The self-test now reported that everything was ok, including the video board SRAMs it had previously declared bad.

However, the game wasn't running correctly yet. At this point I swapped in the other video boards I had available to find the least broken candidate. This also proved that the CPU board was 100% worked and the remaining errors were on the lower video board.

This was all well and good, but I had no easy way of accessing the lower video PCB. This is where a set of interconnects built by UKVAC's ColinD came in handy. I'd had these sat in a box for months, but never had the need to construct them. I soldered them together, and could now separate the PCBs whilst powered up.

Now here's where things got quirky. The video boards all exhibited problems with the 2D static HUD sprites. For example, the "BE 3RD OR BETTER TO CONTINUE" graphic had jailbars. This would often be the sign of a bad line on an EPROM, SRAM or logic chip. I knew the SRAMs were good from the on-board tests so I turned to the EPROMs which weren't tested by the on-board routines.

Using my Sega Sprite Viewer tool, I could tell that these graphics were located in two interleaved EPROMs: epr-11789 at IC 16 and epr-11791 at IC 14.

As a first check I verified the EPROMs out of circuit. I had a little trouble reading them, but eventually got a good read. I put this down to the GQ-4X being a little quirky with 27C1000 EPROMs. I've had trouble in the past with them despite using the recommended jumper wire.

However, I was now really stumped as to what the problem was. I swapped in two EPROMs from another broken video board and got a different visual problem in the same area. I swapped another set in from a different video board and got yet another different problem with the graphics!!

I was really pulling my hair out and spent quite a lot of time checking various stuff. As a last resort, I programmed a new EPROM.

And what do you know... Isn't that unbelievable that EVERY video board had the same damaged EPROM? Maybe there's something about the board's construction that causes this.

Next step will be to verify the controls. I'll do this once the following PCB arrives from Alex that allows you to connect a PS2 controller on the bench for testing and a lot of other nifty stuff. But we'll cover that another time! I may have a (short) break from fixing Power Drift boards for now.