Friday, 25 January 2013

My Weecade - Xbox Based Arcade Machine - Part 5

So it’s been a few months since my last update but I am pleased to announce I have finally finished it (well almost). It’s taken a while but I am extremely happy with the ways it’s turned out.


Since the last update I have stripped down my old Xbox and mounted the parts in the new cabinet. Rather than mounting the entire DVD-ROM drive I removed the PCB and just mounted that instead. As far as the Xbox is concerned it’s a perfectly functioning drive so everything works fine. The hard drive is mounted on the monitor support due to lack of space and the mains in is distributed via a junction box.


For the display I opted for a 17” monitor (flat screen obviously there was no way a CRT was going to fit with everything else in there).  Some people prefer a 19” screen but personally I think that is just slightly too big for a bar top arcade cabinet like this. Converting the RGB video signal to VGA for the monitor I purchased one of these CGA/EGA/YUV to VGA converters.


I know there are cheaper alternatives but I can honestly say this thing is worth every penny. It has a number of inputs including an RGBHV input which I am feeding from the Xbox’s scart. To ensure the best signal possible into the converter I built a sync stripper (based around the LM1881 Video Sync Separator chip from Texas Instruments). The sync stripper basically takes the composite video signal and extracts both the horizontal and vertical sync signals. This way I can feed the converter with clean dedicated component and sync signals. The converter then up scales the video to the native resolution of the monitor. I must say the results are awesome.

Next step sound. For this rather than stripping down a set of old mains powered PC speakers I decided to buy a dedicated amplifier instead. I was toying with the idea of building my own amplifier based on a pair of TDA2003 10W car radio audio amplifier ICs but after pricing it up it worked out cheaper just to buy a kit instead. So I did. It states it’s capable of driving something like 18W per channel but that’s into a load of 4 ohms. The speakers I have fitted are much higher impedance than that so the output power will be significantly lower. This did concern me at first. But after powering it up for the first time I needn't have worried. It is more than loud enough.


Next time an update on the control panel.

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