[Techtoolslist] Kurz Kasch test fixture cards on eBay

[Andrew Welburn]

  The PCB inputs expect 2-bit gray-code, this is easy to accomplish with 
a case statement detecting joystick inputs and incrementing or 
decrementing a couple of variables accordingly (the binary 
representation of the number is the gray code itself).. you just OR the 
two direction variables together and output the 4-bit number to some 
pins in one shot, giving you single a trakball interface. Add a pause to 
the program loop by reading from an ADC input with a pot hooked to it 
and you've got yourself a variable speed digital joystick->trakball 
interface :)

Most modern PICs are so fast that the clunky case statement and 
high-level interface language does not affect the speed. I first wrote 
one of these for a 4mhz pic and it was useable but never quite fast 
enough. Now it runs at 64mhz and is faster than most games can handle, 
which is great, you can slow it down or speed it up accordingly.

Andrew Welburn
http://www.andys-arcade.com

On 03/03/2015 12:25, Matthew Rossiter wrote:
> Hi Andy,
>
> Do you have any documentation on your PIC micro controller setup? That
> would sure be handy as I have about 4 Atari Basketball boardsets that I
> need to get working.  Well, actually I have 1 down, 3 to go.
>
> thanks!
>
> Matt
>
> On 2/19/2015 9:24 AM, Andrew Welburn wrote:
>> years ago i actually built a joystick interface for missile command
>> with a couple of 555's . I found it was possible to simply pull the
>> DIR input high or low to choose your direction and pulse the CLK input
>> on each axis with a 555. This worked in u/d/l/r direction, but when
>> you went diagonal, the cursor would shoot off in the opposite
>> direction. Never quite figured out why, but i was cheating to make it
>> work anyway so it was not a surprise it didn't entirely work.
>>
>> It was crude, but it allowed me to usefully test missile command PCBs
>> enough to fix them on my bench.
>>
>>  These days i use a PIC microcontroller i programmed that properly
>> translates a digital joystick input in to all types of trakball and
>> spinner outputs. Different games count the controllers at different
>> rates, so i've also got a pot that adjusts the speed of the output
>> signals so that all games are playable (for adequate testing purposes
>> only). Its all mounted into my testrig :)
>>
>> Andrew Welburn
>> http://www.andys-arcade.com
>>
>> On 18/02/2015 21:30, John Robertson wrote:
>>> On 02/18/2015 7:02 PM, Matthew Rossiter wrote:
>>>> I bought a set for Atari Tank only to find out I already have it. :)
>>>>
>>>> I notice Kurz Kasch never made a set of cards for Atari Basketball
>>>> AFAIK so I made a pretty nice little rig using a variac to control the
>>>> input voltage.   I just need to make a simple 555 timer - duty cycle
>>>> circuit like they have to mimic the trackball in other games so that I
>>>> don't have to hunt down a 4.5 inch trackball.  Anybody got a schematic
>>>> I can use?
>>>>
>>>> Matt
>>>>
>>> Don't you need two pulsing signals for each axis? Rotation and
>>> direction? How can you do that with a single 555 timer? Seems to me you
>>> would need a dual timer with an offset depending on which direction you
>>> want to 'go'.
>>>
>>> Or am I missing something?
>>>
>>> The Atari CTS-1 used a dual opto spinner for this sort of thing.
>>>
>>> John :-#)#
>>>>
>>>> On 2/18/2015 4:16 PM, John Robertson wrote:
>>>>> Coinopwarehouse has about 75 cards up for sale. I bought a few, and
>>>>> they are in good condition. Lloyd said most didn't come with
>>>>> documents, but he does include what he has. He will combine ship too.
>>>>>
>>>>> Worth looking at if you are rounding out your collection or want to
>>>>> trade with me sometime...
>>>>>
>>>>> stores.ebay.com/coinopwarehouse?_dmd=1&_nkw=kurz
>>>>>
>>>>> John :-#)#
>>>>>
>>>>
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>>>
>>>
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>
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