Modding March, update 2


More modding news!

I’ve finished off the tweaks to my Astro City’s control panel, and I can now swap in/out P1 and P2’s respective fourth button off the JAMMA harness, handy for my neglected MVS (which is now in my cab, giving Marvel vs Capcom a much deserved rest).

I’ve also disassembled my XB360 to get the model number of the DVD-ROM unit (which I could have simply ascertained by checking the cable off the front with the faceplate removed, but I figured I needed to disassemble it anyways so went ahead with it regardless), added a bit of hot glue to my SMS2 to reinforce one of the screws holding the dual-mono audio plate on the rear of the machine and also took apart my A500 to remove the floppy disk drive as I’m looking at grabbing a HxC Floppy Drive emulator and mounting it internally on my system (something I think Old School Game Blog would appreciate given his huge knowledge and appreciation for Commodore computers!).

In addition, I’ve had confirmation that the replacement Saturn cart slots are on their way, and the 10mhz oscillator for the SMD is in the post as well. If all goes well, I should be able to get the whole list done within a couple of days of April ๐Ÿ™‚

I’ve also started thinking of tidying up a couple of other console mods – fellow modder Mamejay has shared a circuit for getting extremely nice composite and s-video off a PAL Atari 2600 (adapted from an A2600 Jnr mod he’s been doing for a while), so I’ll grab some CD4050s to give it a whirl. I’m also toying with the idea of overclocking my PAL and Japanese N64s since I still have a couple of switches in my stash.

So, the revised list (which will take me into April) is as follows:

  • Sega Mega Drive 10mhz overclock
  • Sega Saturn cartridge slot transplant
  • Atari 2600 AV mod
  • N64 overclock (PAL and Japanese consoles)

With all of those done, I’ll definitely have caught up on my backlog!

I’ll be looking forward to reporting back on when these are finished, as it means I can get started on two larger projects I have planned for this year, but details of those are to come down the road!

Overhauling the Sega Astro City โ€“ Part 13, final thoughts

Wow, who would have thought I’d actually get to this post, let alone finishing the project?

Well, the project was actually finished up a few months back, but I’m glad I got this post in there to round things off. This was a pretty big undertaking for me since it was my first arcade cabinet overhaul, and I have to say it went really well. The cabinet’s running beautifully and is happily playing anything I can throw at it. Once I have my Naomi IO and get around to building a converter for Model 2/Model 3 boards, I’ll be absolutely done.

So, with all this experience in mind, would I have done anything all that differently?

To be honest, not much went awry – I’m happy with the end result, and there have been no dramas with the setup. The only changes I’ll be making is that I’ll be splicing in button 4 for players 1 and 2 from the JAMMA harness into the JAMMA+ harness wiring to save swapping connections, but that’s it.

Thanks for sticking with this series of posts – if you want to check out the whole series there’s the Sega Astro City Overhaul tag, but for convenience, here’s the full listing:

Big thanks to the Aussie Arcade crew for helping with some daft questions throughout the process, it’s an amazing community of enthusiasts over there!

Now with this one sorted, I’ll have to see what my next project entails!

Overhauling the Sega Astro City โ€“ Part 12, replacing the monitor

Of all the aspects of the overhaul, replacing the monitor was the one I was dreading. The big 29″/68cm tubes are heavy, you have to be careful discharging the tubes and I was worried about scratching the new screen ๐Ÿ™‚ To my surprise, it actually wasn’t too tricky.

First up, the monitor (i.e. tube, chassis and mounting cage) had already been removed from the cabinet while I was rewiring it. I discharged the tube safely, grabbed a cushion off a nearby couch, and gingerly laid it face-down on the cushion so I could work on the cage and chassis without worrying about cracking the tube:

After using my capable screwdriver that will allow the shaft to bend at 45° and 90° angles and treating it like a wrench with a big phillips head screwdriver tip, I managed to remove the cage from the tube:

With that finished, here’s the chassis I removed the chassis from the cage before starting on the tube:

This left me with a nice empty cage to work with:

Next up, I grabbed the fresh, shiny Universal Chassis I ordered a while back for this job. I sourced the chassis from Jomac, who happen to be an amazing team to work with, provide expert advice and offer extremely competitive prices (in other words, they come extremely highly recommended). I then mounted the chassis to the cage like so:


Next up came decasing the tube. I was able to source a Teac 68cm TV circa late-90s/early 00s from my parents that was perfect for the job – 68cm tubes are an almost 1:1 replacement for 29″ arcade tubes and are amazing quality. Paired with a Universal Chassis solution from Jomac, and I had a dual-resolution 15k/24k monitor for the price of a chassis, no need for factoring massive costs for sourcing arcade tubes.

Anywho, the tube was safely discharged and I repeated the same process as before – gingerly lower the whole TV onto the cushion, then begin de-casing it:

A bit of patient gruntwork later, and I’m left with the tube on the cushion awaiting the cage:

Simply mount the tube to the cage very carefully, ensure all the connections are solid, and I went about wiring up the degaussing coil, yoke connections, mounted the neckboard and ensured all the ground connections were fitted. This is the end result:

Front –

Side –

Rear –

The whole process probably only took 30-45 minutes, including discharging the tubes again at the start of the session – I had previously discharged them the day before and did it twice during the session to be extra careful with them.

All that’s left now is to plonk the monitor back in the cabinet, fit the front cover including the bezel, connect all the wires and run a smoke test, then the cabinet will be complete. Expect that report in the following (and hopefully final!) part in this series ๐Ÿ™‚

As noted before, posts on the refurb are being done ad-hoc, so to keep track of the whole project, just use the Sega Astro City Overhaul tag, as the whole series will be added to it over time.

Overhauling the Sega Astro City โ€“ Part 11, rewiring the cabinet

This one is best told in pictures. Let’s start with the before:

Looking inside the cabinet from the outside:

Closer up:

Power supply in focus this time:

Molex connections galore:

And the AC wiring, complete with heatshrink tubing and solder for the spliced connections:

Here’s the aftermath, with all the control panel wiring intact (since it will be reused), and all the excess wiring removed:

And for the sake of completeness, here’s the control panel without the bracket that houses all the molex connectors:

Now that all the wiring is out, next came the step of stripping everything out of the cab – the outer layers were removed that hold the bezel and speakers, exposing the fluro tube, and the monitor in its entirety (cage included) was also removed. To open up the insides for working, I also removed the partition that holds the PCB holder and separates the two halves of the cab. It really is looking like a shell now.

So, let’s start the refit – here’s a shot of the inside of the cab with only the new AC wiring present, with everything terminating to a female socket for ease of use:

Next up, add the step-down transformer to the partition to the right:

Add the partition to the cab and mount the SUN PSU into place; it’s positioned to allow for thick PCB boards, the MAME PCB or CPS2 setups, but still retain access to the unit for adjusting DC voltages:

… and another shot:

This next show shows the control box and the power board attached to the side of the cabinet:

The following closeups demonstrate when the control box and power board sit:

… and another:

… and another one:

Almost there – the JAMMA harness has been added, molex connections are complete and cable-tied close to the frame, JAMMA harness is hooked up and some RCA connections have been added for the output on the control box:

And there we go – all finished and much neater than before!

That takes care of the cabinet, but what about the control panel? We can’t forget that! Here’s a shot with the amp installed with all the wiring to the speakers and control box completed and the bracket re-installed:

And here’s the final shot with extra earth wiring grounding the monitor frame, amp, bracket and the coin slot chute/coin box:

Bit of a marathon run, but it came out really well. Next up – the new monitor!

As noted before, posts on the refurb are being done ad-hoc, so to keep track of the whole project, just use the Sega Astro City Overhaul tag, as the whole series will be added to it over time.

Overhauling the Sega Astro City – Part 10, mounting the MAME PC

I’ve talked before (here and here) on the MAME PC I’ve worked on as part of this project – today I have some images to show how I set it up.

The aim was to have the PC mounted in a way that would easily allow me to swap it in/out of the cabinet like a PCB. To do this, I therefore needed to have it mounted on something, and due to the size of the chamber in the Astro City, I also needed to take space into account. I actually got the idea from some ghetto DIY arcade sticks I’d seen on the net, and I have to say I’m pretty happy with the end result.

It’s made up from a slab of MDF that I cut to size just slight larger than the motherboard with the mounting legs, with some extra give on the side where the accessories (graphics card, etc) stick out to allow for space for VGA adapters. The motherboard is propped up on PCB legs and screwed into the MDF to hold it in place. The top layer where the PSU, HDD and JPAC sit actually has two 80mm holes cut in a figure-8 shape that allows the CPU cooler to vent into the PSU and then have the PSU exhaust the air. To insulate the JPAC, I grabbed an old plastic VHS tape case and cut it to shape the JPAC with a rotary tool and that’s placed between the JPAC and the MDF. Small squares were then cut to act as plastic washers for the bolts so that the JPAC’s PCB wasn’t damaged when bolted down.

The poles supporting the structure were actually one long screw rod I got from the hardware store with an M10 width. Appropriate nuts and washers bind it for each layer, and I simply cut it to the necessary sizes using my angle grinder.

Everything was sized up, and bolts secure all the pieces of the setup, including cards in the motherboard, the PSU, JPAC and HDD. All the cables are secured using cable ties. The power button is routed to a DP3T switch I had lying around – simply flick it up, and it mimics the use of a power button.

All up, it works well, even if it is probably a bit rough ๐Ÿ™‚ I like it though!

As noted before, posts on the refurb are being done ad-hoc, so to keep track of the whole project, just use the Sega Astro City Overhaul tag, as the whole series will be added to it over time.