Sega Net City HD – part III

Going wide

In my previous attempt on an HD cabinet I was planning on using an Atomiswave SD cabinet. This proved to have more than one drawback. It could only house a 26″ monitor and the tilt of the screen was too large for providing a decent viewing angle. In the Naomi/New Net City we can squeeze in a 27″ wide screen monitor (which is much easier to come by) and it’s also more upright and since viewing angles are an issue with LCD/LED monitors this is preferred. Apart from the usual criteria when selecting a monitor; low input lag and response time, we also had the following:

  • Case (frame) had to be possible to remove.
  • Centered VESA mount directly on the panel (since the case has to go).
  • Easily detachable control panel.
  • Fast switching between 16:9 and 4:3 screen formats.

The big issue of course was how to know what the panels looked like on the inside without taking them apart? Luckily an acquaintance works for a company repairing monitors and he was able to help us in our search. In the end we let go of the fast format switching and decided on a Philips 273E3LHSB. DSC09610 As you can see from the picture above the monitor will fill up the space entirely. There’s gonna be a lot of sawing in both the bezel and the front cover! In the pictures below you can see the bare panel and how it fits behind the front cover. Notice I had to cut away the bezel entirely on the sides – maximized monitor area 😀

Part of the front cover also had to go for allowing space for the monitor.

To test the mounting and rotation I used a plywood board I had lying around. There’s plenty of space between the back and the front cover and I ended up constructing a riser for the monitor mount. I feared the monitor would become wobbly but no. It sits sturdily behind the front cover. There’s enough room around the monitor for housing the front, center and surround speakers without getting in the way when rotating the monitor. Speaking of the speakers…at the moment we’re looking at the Logitech Z-906 system. Plenty of good sound and the satellites are small enough. Only issue is how to house the sub-woofer. But more on that later.

Next up: a new lamp cover.


Sega Net City HD – part II

Cutting it down

Our plan is to make a sit-down cabinet, much like the New Net City. So the first step in order to get a feeling for the profile of the finished cabinet was to cut the legs down.


I shortened the legs by 338 mm. Easiest way to get the holes correct was to start with the holes for the two bolts on the base. Then mount the legs and mark up the holes for the three remaining bolts.


With the legs in place it was time to get a glimpse of the future. Since my donor cabinet used to be a Wild Riders I had to find both a control panel surround and bucket. Luckily Johan, who sold me the cab, also had a surround and moshpit over at AO had a spare bucket lying around – et voilà – meet the Net City HD – the WIP version 😉


The looks

Stompp and I have been throwing ideas back and forth for a long time. This is one of the mock-ups we’re working on at the moment.


Base color of the cab is going to be gun metal gray, the bezel will be modified to fit a 27″ wide screen LED monitor and get covered with a carbon fiber vinyl (looks awesome and will be much easier to apply than an A-grade paint job).

Left, right and center speakers goes below the bezel and the VMU cover gets replaced by black speaker grid. The surround speakers will be placed where light cover is and the cover also gets replaced by a speaker grid.

The notch between the bezel and the surround speakers will get a new lamp cover and house a blue LED strip.

No Wild Rider part were harmed in the process!
No Wild Rider parts were harmed in the process!

Stompp took pity for the Wild Rider parts and some day, hopefully, they’ll go Vrooom!! again.

Next up: the monitor

Sega Net City HD – part I

Never heard of it? Well, it’s probably because it doesn’t exist – yet.

The Net City HD is a project between Jonas (Monouchi) and myself. We’ve been planning this for some while since Jonas abandoned his Atomiswave HD project a while back. The background to the project is that both of us has been wanting an HD cabinet for playing newer arcade games and also taking advantage of the many good titles developed for (or ported to) the Xbox 360.

While there are a few HD cabinets out there, like the Vewlixes and Deltas, we feel most of them are quite bulky and not too great looking. Jonas’ Atomiswave project fell short due to a number of reasons, most of them related to the monitor. So, which arcade cabinet would lend itself well as a donor for being converted into an HD cab?

The victim
The victim

We decided on the Sega Naomi Universal.

It has a more upright profile than the AWSD, it will be extremely slim removing the bulky back cover, it’s easily transformed into a sit-down cabinet, there’s plenty of room for making cool mods and last but not least – it will look AWESOME!

Looking for scrappy Naomi cabinets proved much harder than we thought. Suddenly the market was empty of them. Jonas ended up picking the short straw, getting a Wild Rider cabinet for which he had to find a whole new control panel surround since the WR of course is a special one. I was lucky to find a Virtual Striker 2002 cabinet in decent shape only a 2½ hour drive away.

The pickup

A few weeks ago my wife and I jumped in the car for picking up the Naomi at Motala Arkadhall. MAH is a place run by three arcade game/pinball enthusiasts; JFH, Larsson and priest.

Taking the Naomi apart took less than half an hour leaving some time over for coffee and a few credits!

The brainstorming

At the moment Mono’s already cut the legs on his Naomi and started with the refurb. Me, I’ve got two rooms to renovate that kinda takes priority. Meanwhile we’re throwing ideas back and forth: monitor selection, rotation mechanisms, sound system, speaker placement, electronics, wiring etc.

One thing’s for sure: there will be carbon fiber!

Next up: Cutting it down.

More inlays

Looking for storage options for different kinds of media – Naomi carts, Type X² HDD’s, MVS, PGM etc I stumbled upon a box from Game-Trader in Germany. The boxes are quite a bit larger than Shockboxes but the upside is that they swallow a whole bunch of types of games.

Arcade Gamebox

As you can see they measure 205 x 295 x 57 mm. The foam containers are available for MVS, PGM and Atomiswave games but with a knife you can easily make room for even Naomi carts using an Atomiswave foam.

Naturally Shockbox inlays don’t work well with these boxes so only thing to do is to start creating new inlays. Since I anyway prefer to do things my own way this was no real issue for me.

Still experimenting with the template. Not quite sure whether I prefer horizontal or vertical print on the spine.

Progear no Arashi Conversion

Nice EPROM labels

I killed a Vampire Hunter CPS2 board!

Conversions are kind of a grey zone within the arcade world. They’re neither bootlegs nor originals and trading them is banned on many arcade forums. Instead of creating a copy from scratch you take an existing game and reprogram (usually by changing the chips) into another. While it is not considered ok by some this was done by the game manufacturers too.

Progear no Arashi and Hyper Street Fighter II: The Anniversary Edition are probably the most common conversions on Capcom’s CPS2 platform. Both are ridiculously expensive as originals and fairly easy to make conversions of.

After baking a few Naomi and MVS BIOS chips I wanted to try my luck with a Progear conversion. I picked a cheap Japanese Vampire Hunter as donor and got started.

Vampire Hunter CPS II B Board
Vampire Hunter CPS II B Board

The first thing I realized was that Vampire Hunter uses a PAL F type board which meant I would have to do the ugly patch, ending up with a cable across the board. If you can get hold of a PAL G board you won’t have to do this.

For the Progear conversion you will need:

  • ROM files (easily found all over the net)
  • 1 x 27C010 EPROM
  • 2 x 27C4096 EPROMs
  • 6 x M27C322 EPROMs
  • A programmer capable of programming the above IC’s
  • An EPROM eraser (if reusing IC’s)
  • About 30 cm wire (if donor board is a PAL F type)
  • Soldering/desoldering tools
  • A T-20 security torx (for opening the case)

The 27C010 and the 27C4096’s you can reuse if you have an EPROM eraser (if you don’t – get one). Though in my case the VH had 27C1001’s and I couldn’t any get them to work so I had to get a new 27C010. The M27C322’s are easily found on both eBay and AliExpress.

Erasing EPROM's
Erasing EPROM’s

Use a decent UV eraser for wiping the EPROM’s. Don’t build your own! You can find one cheap from eBay and messing around with UV light can make you go blind. I usually leave the EPROM’s for about an hour in the eraser for making sure that they’re blank.

Since CPS II boards are suicidal it’s also a good idea to remove the battery while converting and create a phoenixed board. For this you need phoenix version of the ROM files.

CPS II Battery and CC1 capacitor
CPS II Battery and CC1 capacitor

Desolder the battery from the board and short circuit the CC1 capacitor for draining the board completely from any residual charge and the remove all IC’s from the sockets.

Vampire Hunter PCB with IC's and battery removed
Vampire Hunter PCB with IC’s and battery removed

Now’s a good time to clean the board if it’s dirty. Wash it under lukewarm water using a mild detergent and a soft toothbrush. Rinse well and leave the board to dry for a couple of days. In case you have a hot air oven that can be set to a temperature of 35-40°C (85-105°F) you can speed up the drying process.

Next you need to set the jumpers correctly. There is a total of 28 jumpers on the board. Jumpers 1-6 above IC socket 1, 7-12 between sockets 2 and 12, 13-20 below socket 16 and 21-28 below socket 20. Depending on your donor board you might have to cut, solder and/or desolder the jumpers.


The jumper settings (from 1-28) are:


If you, like me, have a PAL F type board you’ll have to apply a patch cable from the BGS-B3F IC to pin C13 of the C1 connector across the board. Remove the BGS-B3C IC from the board and bend leg no 7 outwards so it no longer connects to the socket. Solder one end of the wire to the leg. Reinsert the IC and solder the other end of the cable to pin C13.

Patch cable
Patch cable

For programming the EPROM’s you’ll need a programmer with a 42 pin ZIF socket capable of handling the three chip types. I use a TOP-3000 universal programmer which can be found on eBay and other stores for about $150.

Once you’ve programmed the EPROM’s make sure to cover the windows on the chips. There are special metallic labels for this but normal electrical tape works just fine.

Insert the EPROM’s and take your game for a spin!

Testing the game
Testing the game

Case labels and manual can be found over at the ArcadeOtaku wiki. And for giving your board the last final touch print some nice looking EPROM labels.

Nice EPROM labels
Nice EPROM labels
Progear no Arashi CPII A and B boards
Progear no Arashi CPII A and B boards

Related links

Naomi Pi

Netbooting your Naomi is about to get Raspberry flavored. Naomi Pi 1 For a while now I’ve been thinking about different ways to netboot the Naomi. Yes, it’s quite handy being able to load games from your nearest computer but why not take it further?

How about doing it from your arcade machine? Pretty handy, no?

I had a Raspberry Pi lying around I didn’t know what to do with so I thought what if it had a display and some way to control it? After some search I found an expansion board with a 20 x 4 LCD display and some buttons from BitWizard. The Naomi Pi was born.

The general idea is to hook it up with keyboard and monitor for some easy config (setting up IP addresses the mounting NFS volume etc) and then setting it up inside the cabinet for easy loading of games.

Stay tuned for updates 😉