Re: Parallel Card

["Bryan Parkoff" <none@nospam.net>]

Matt,

    Thank you for the explanation.  I am very curious about the timing on 
Apple //e.  HAL16R8 chip contains 16 timing possibilities.  This chip has 8 
inputs and 8 outputs and 8 registers as inside another 8 inputs.  I only 
want to view 8 outputs.
    How is it possible that game connector can be done?  I write assembly 
language to send one byte as 256 possibilites from the memory to the game 
controller.  Then HAL16R8 chip receives 8 inputs and transmits 8 outputs 
back to the game controller.  Eight outputs is stored into memory.  I view 
stored bytes in memory.
    Do you have draft schematic that it might help me to design in my own? 
Michael Mahon said that two parallel cards are only the answer.  I think 
that game controller card might be a good idea for money saving.

Bryan Parkoff

"mdj" <mdj.mdj@gmail.com> wrote in message 
1148560743.569435.69860@u72g2000cwu.googlegroups.com">news:1148560743.569435.69860@u72g2000cwu.googlegroups.com...
> Hi,
>
> IMHO the best parallel card for the Apple II is the ProFILE interface
> card, as they're bidirectional, but these are almost impossible to
> find.
>
> If you simply want to drive/test 16 LED's, you can do this easily, and
> extremely cheaply from the game connector, and save yourself some
> money, and 2 slots.
>
> Just grab two 74LS164's from the local electronics shop. This component
> is an 8-bit shift register. In essence, you connect the reset, clock
> and input pins of a shift register to the annunciators on the game
> port. Each of the 8 outputs is then connected to an LED.
>
> A very simple program can then be written to 'shift' 8 levels into the
> register, allowing you to turn on and off the LED's.
>
> To add another 8 LED's, simply 'cascade' another shift register by
> connecting its clock and reset in parallel, and wiring it's input in
> parallel to the 8th, or H output of the first register.
>
> Using this technique, you can control a *lot* of LED's very easily.
> It's much cheaper than a parallel card and a lot more fun :-)
>
> Matt
>