Overhauling the Sega Astro City – Part 7, working on the MAME PC

MAME PC on the workbench

As part of the Astro City overhaul, I wanted to recycle my old P4 hardware and use it on the Astro City. To get there, I’ve installed WinXP since I still had the license valid for this PC, along with MAME 0.128 that I had handy, and will use GameEx as the frontend. The following are the hardware specs:

CPU: Pentium 4 Socket 478 3.2ghz CPU with Hyperthreading
Motherboard: Gigabyte GA-8S648FX
GPU: Gigabyte ATi Radeon 9600XT w/256mb RAM
RAM: 1gb DDR-400
HDD: 40gb Seagate IDE HDD
Network: 10/100mbps LAN NIC

As you can see, it’s nothing terribly powerful by today’s standards, but it’ll have enough juice to run classic sprite-based games, which is what I wanted. The beauty is that with the LAN card, I can remote into the machine once the initial install’s done for maintenance and setting up programs.

To interface the PC with the cab, I’m going with a J-PAC interface, which takes the VGA and PS/2 sockets from the PC and puts them into JAMMA standard so you can simply connect the PC to the cab via the JAMMA harness. You need to push the video card into outputting a 15k signal though, which can be done on most ATi cards by using Soft15k, and it worked fine for my setup.

Special note to all J-PAC users though, be sure to set the jumpers on the J-PAC PCB to 15k – I was getting a rolling picture when I first booted and thought something was wrong with the video card or the chassis. I powered off the PC and set the jumpers as per the below, which also happens to be the configuration Ultimarc (the manufacturer) suggest you use 😛

JPAC - properly setup!

… and it worked fine after that 🙂 The only other issue is audio, but since I’ll have an amp in the cab as part of the overhaul, I’ll just have a 3.5mm headphone socket to stereo RCA cable ready to plug in and run it that way. Sorted!

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 4, PC addition

Continuing on from part 3 of this series, let’s move on to part 4 – adding a PC to the cab.

This one came as a bit of an afterthought, but after upgrading my old workhorse S478 P4 3.2ghz PC, I thought it would probably be fine getting relegated to the cab. The cost adding this functionality is pretty minimal, as I still have the valid XP license and the video card’s an ATi Radeon, which have good rates of success running Soft15k. All I’ll need is a J-PAC, and I’ll be fine.

To simplify the procedure, I’ll keep the network card in the machine and administer the PC over the network, and run a customised nLite install to trim out all the unnecessary gear. I’ll rig a momentary push-button to take care of powering on the PC with one of the spare slots I have under the CP (or I’ll add it to the project box housing the switches for the fans, negatron, etc) and mount the PC inside the cab. Easy. I’ll have to customise the gamelist to suit the hardware and monitor since I’m only after 15k titles, but it shouldn’t be too tricky. As a bonus, it also means I can use my recently acquired XM1541 adapter to run off the machines LPT port since my new desktop PC lacks that kind of hardware.

So that’s part 4 – part 5 will note the summary, and the posts thereafter will be ad-hoc updates.

To keep track of the whole project, just use the Sega Astro City Overhaul tag – the whole series will be added to it over time.