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Scratchbuilt PONG - 56K warning!
tnpshow:
Hey All,
First real constructive post here...
It's my first scratchbuilt cab and I decided to build it for a few reasons:
1. It's pretty cost efficient materials-wise
2. It's got great historical value
3. It's a great, easy shape cab to build (for your first one).
4. No original PCB or PC required - this thing is as simple as it gets!
5. Artwork is as simple as it gets (ok the control panel wasn't so simple, but we had the right tools at work). With the pre-laminated chipboard, there's no painting either!
I got some (very) rough plans off the Atari forums and with the aid of just about every picture I could find on the net, I pieced together some plans in AutoCAD.
This cab is slightly smaller than the original (about 10mm narrower and shallower) because it turned out the local builders supply had 595mm wide laminated chipboard available in a nice
woodgrain and a nice (ok, sickly) yellow. Perfect!
On with the build:
I went to the builders yard and got them to cut each piece of laminated chipboard to the correct lengths (saved a butt-load of time :)). I used two 595mmx2400mm lengths of 18mm thick woodgrain laminate and one 595mm x 2400mm length of Yellow laminated woodgrain. Later on for the cab floor and shelf I used some plain chipboard.
At work I laser cut all of the curves and non-square profiles into thin (3mm thick) pieces of MDF. This was the profile of the cab sides at the top, the coin slot cut out and the bezel cutout.
I taped these down to the chipboard in the correct spots and cut them roughly with the jigsaw and then finished them with the router...
Once one side of the cab was done, it was clamped to the other side and I then used the router to copy it. Easy!
Once most of the parts were cut and shaped, it was time to assemble!
I bought some ribbing from Bunnings (about 20 x 35mm) and fitted the bracing to the sides of the cab. Using a template made from one side I managed to align the angled braces nicely, making both sides symmetrical.
Then I made a solid base from some pine lengths I had lying around.
Next, one side was attached to the base.
With the sides clamped together using other parts, I screwed both sides to the base. It was an absolute b!tch getting them square and I still don't reckon they're perfect :-(
Then it started looking like a cabinet!
tnpshow:
Monitor is a de-cased TV. I left the TV chassis intact. The electronics I'll be using are an old 'Tempest' TV game which has Tennis (Pong), Squash, Soccer, Practice and a couple of shooting games.
I got it off ebay and it plugs straight into the TV. Even if the game has been powered off, Pong comes up straight away when you switch it on, so I was pretty happy with that.
I made a mount for the TV tube and fitted it in place.
Mounting the TV chassis was a bit tricky due to the length of the yoke and HT wires, so I ended up putting a brace in the back of the cab and using the bottom half of the TV case (precision jigsaw mod of course) and screwed it to the back brace.
Then the control panel. The original PONG was a piece of aluminium with the lettering silkscreened in black over the top, but I decided to go for something a bit better. I replicated the panel in Autocad (very painstaking because I had to make my own font) and cut it on our CNC engraver at work.
Then I rubbed back the plate, painted the lettering black and then rubbed it back again to get a nice contrasting look happening. If I did it again, I would have had the plate anodised a natural finish for an even better look, but oh well...
Some nice 38mm knobs from Farnell fit the 70's theme nicely... 500k linear pots were used (new ones were bought as the old TV game ones were very worn and noisy).
The PONG 'marquee' is just black vinyl done on our CNC knife cutter at work. Came out a treat!
tnpshow:
Next up was the coin mech - Ozstick supplied the retro coin mech and after a slight adjustment it was munching 20c pieces like there was no tomorrow.
One major design flaw with these early machines was the coin access. There was no door on the front and in order to empty the bucket, you'd have to pull the machine out and empty it from the back.
This is why you sometimes see pics on the web of these machines with a 'normal' coin door fitted.
To address this, in addition to the coin mech microswitch, I added a second microswitch in parallel to the reject mechanism so that if you press the coin reject button, it starts a new game. no coins needed, but if the 'novelty urge' grabs you, you can chuck some 20's in to play.
Black T-moulding was fitted (from Ozstick). I got a slot cutter for my router from a local saw dealer for $33. Absolute bargain!
The bezel is made from lasercut thick card and then sprayed flat black. It's a tight fit but looks the goods! Unfortunately I don't have a pic of it out of the cab, sorry...
The 'glass' is some thin lasercut perspex screwed to the inside of the wood bezel with some small screws.
Electrical stuff was next. I put a combo IEC+Fuse+Switch on the back of the cabinet so I can unplug the mains cable for moving. Directly on the other side of this, I fitted a surface mount adaptor and double GPO for the TV and the Pong unit's plug pack.
Some adhesive cable tie mounts were used to keep all of the cabling in order. I also ran an earth wire from the front control panel (all exposed metal), to the coin mech, and then back to the earth on the GPO inside.
I made a cradle for the Tempest PONG out of aluminium angle and it fit quite snugly.
Before I stuck it in, I pulled the unit apart and soldered 2 wires across the "start" button on the main PCB. This basically resets the AY-3-8500 IC and starts a new game. These two wires then were fed out of the unit and off to the two coin mech microswitches. Easy!
I also pulled apart the two had controllers and desoldered the wires from the pots. I then soldered the wires onto the brand new pots on the control panel.
It fired right up!
Finally, I added a back door complete with barrel lock and put it in place.
tnpshow:
And here it is, beside my computer desk!
It's been an interesting build - made a few mistakes and learnt a heap.
Maybe after the novelty wears off I'll MAME it or chuck a PS3 in it for some fighting games :badgrin
Can't wait to start the next one. Maybe a Galaga or Gyruss...
A heap more photos and hi-res shots HERE
Cheers for looking! ;)
EDIT - CAD files are HERE
sparcade:
Excellent build!
I envy you guys that have access to CNC machines :)
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