Jefcade Supergun
Back in 1994 my brother made a small portable JAMMA arcade machine which would later be known as a Jefcade Supergun for desktop use, this again plugged into the great Phillips CM 8833 MkII 14" Monitor.
The extra items my brother added to the joystick were Autofires on all three buttons (much easy playing shoot'em-ups). The Autofire can be switched between three modes.
- 1 - Autofire - Off
- 2 - Autofire - On (but you must hold the button)
- 3 - Autofire - Full auto (no button holding requred)
The three LED's flash with the speed if the Autofire, the three Potentiometer adjust the speed of each Autofire. The 1 Player button also lights up.
About the only problem with the design at the time was that a standard Maplin's project box was the only thing that it could be made from and is a little boxey.
Three 555 timers were used to achieve the Autofire for each of the three buttons..
Very neat and tidy, as it uses the 5v rail, it's also protected by a fuse.
The three preset Potentiometer are for setting the 555 timers to the lowest setting in speed without stalling the clock pulse, sort of trim adjustment.
Below is a list of all the components that were used in the circuit (price are quite a bit out of date).
I will try to make a circuit diagram at some point and maybe even update the design, I think if I was making one I would make it for just one buttons and then make three of them, this would make the design a little more modular.
At the time the project was originally made, you could get single 555 and the 556 dual timer, now you can get the 558 quad timer, so the PCB could be simplfied down to just one IC as only three channels are needed.
https://en.wikipedia.org/wiki/555_timer_IC
Maplin Code | Description | £ Each | Quantity | £ Total |
---|---|---|---|---|
QH66W | NE555N Timer | 0.29 | 3 | 0.87 |
BL17T | 8 Pin DIL IC Socket | 0.14 | 3 | 0.42 |
VJ56L | Plastic Fuse Cover | 0.19 | 1 | 0.19 |
GJ85G | Fuse 315mA QB (Pack of 20) | 0.79 | 1 | 0.79 |
KU27E | Fuse Clips 20mm with In-Line Pins Type2 | 0.07 | 2 | 0.14 |
UH02C | 4K7 Preset Potentiometer (349M) | 0.19 | 3 | 0.57 |
VH02C | 0.47uF 63v Capacitor | 0.06 | 3 | 0.18 |
VH08J | 10uF 50 Capacitor | 0.06 | 3 | 0.18 |
M47K | 47K Ohm +-1% Resister (Yellow, Violet, Black, Red - Brown) | 0.07 | 3 | 0.21 |
M1K8 | 1.8K Ohm +-1% Resister (Brown, Gray, Black, Brown - Brown) | 0.07 | 3 | 0.21 |
M1K6 | 1.6K Ohm +-1% Resister (Brown, Blue, Black, Brown - Brown) | 0.07 | 3 | 0.21 |
WX77J | 10000pF Dia 6mm Metallised Ceramic Plate Capacitors (103Z) | 0.05 | 3 | 0.15 |
JP52G | Strip Board (cut to 31 [W] x 21 [H] Holes (Horizontal Strips)) | 3.29 | 1 | 3.29 |
FL24B | PCB Solder Pins Type 2145 (100 Pack) | 2.99 | 1 | 2.99 |
FL25C | Spot Face Cutter (for cutting the Strip Board) | 7.49 | 1 | 7.49 |
CK46A | Red LED 5V | 0.26 | 3 | 0.78 |
JM76H | Miniature Potentiometer Lin 1M | 0.49 | 3 | 1.47 |
RS Code | Description | £ Each | Quantity | £ Total |
337-481 | Slide Switch, 1A, 100V, 2 pole, 3 Position | 1.45 | 3 | 4.35 |
Controls | Description | £ Each | Quantity | £ Total |
One Player Button (optional bulb) | 1 | |||
Buttons (choose your own colours) | 3 | |||
Joystick (of your choice) | 1 |
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