For those, who want to design own Interfacecards ( reagrdless if they are
aiming to connect a external device to the computer or make a card for
special use like Audiocard or Measurementcard ) itīs a rather good idea to
read the mentioned book. It explains which laws rule the design of
Apple II Interfacecards and how to access the cards from Software. The
included experiments target to demonstrate how the adresses on the
interfacecard are hardwired and how to use that hardwired adresses from
within the program as input or output ports and the different techniques
how to code and access that ports.
Unfortunatly the book only contains the description of a kind of
Prototyping board that shall be used between the Apple II and the
breadboard,
but lacks about the layout of such connection - it only has splitted parts
of circuitplans of such protoboard.
Therefor the following description might be quite usefull to those, who
intend to perform the experiments described in the book and donīt want
to
start up from the scratch and collect the sircuitplans, join them together
and make that prototypeboard to create the connection between the
breadboardsystem and the Apple II. This board contains the chips and the
layout how to monitor the the interface and the coded logic on the
breadboard and therby verify the own design by experiments.
Targeting to save resources the Interface for the Apple II and the
prototyping card are linked together as one large board and after making
that board
the user may saw the interfacecard apart and link both boards with a
flatribbon cable. this permits the interface card to stay inside of the
Apple II ,
while the prototyping board and the breadboardsystem remain outside apart
of the Apple II.
Here is the general view of the prototyping card and
the interfacecard after they have been sawed apart and connected
together with a
flatribbon cable. Please note that the prototyping card has a section on
board that is designed to supply the card and the breadboardsystem
with independant stabilized power from external transformator with 24 Volt
and 12 Volt ( both brancehes each 1 Ampere ). The only requirement
is that the GND od the Apple II and the external systems are linked
together to ensure that the systems interact with the correct voltage
levels.
This is assured by the connection of the interfacecards. In case that the
external powersupply is used the wires connecting the power from the
Apple to the prototypingboard should be not soldered in place.
Please also pay
attention to the red side of the ribboncable indicating the side of pin
1 !
here is the view to the solderside of the
card:
Here is the view to the traces at the componentside:
And here is the view to both layers combined
together:
and here is the view to the layout of the
components:
Please note
that several chips have been placed inside of larger IC-sockets. The
purpose is the each pin of the chip has connection to 2
pins of the larger socket and therefor there are for each pin of the chip
2 pins availiable for access at the surrounding socket for use with
the breadboardsystem.
Those chips which are proposed for use only by one connection the related
socket to grant access to the pins is located besides of the
chip and grants only one pin access to the related gate.
This is explained by the colored fields of the
following picture:
For use of this
board itīs highly recommended to download the related book by using the
link in the title of this page
and read the book before starting up with the experiments. Otherwise you
might damage your computer !
The basics explained in the book are essential for understanding the
experiments and preventing the system
from harming the computer !
and of course here a view to the
circuitplan:
Alternatively i also publish here the
"older" version i made about 25 years ago.... in those days i etched my
own single sided PCBīs
at home with a "home brew" etching system by lighting the PCBīs with
ultraviolett lightbulb and afterwards etching in a cavern made
of acryl and heated with a heater usually used in aquariums and
transferring air bubbles in the cavern / tank with a pump used for
adding air in the water of an aquarium.
due to european laws and german court decision:
I hereby declare no responsibility to any "deep links"
resulting from the links in this page. I have no influence to
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direct the readers browser to nor to the
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The reference to contents by this links is dependent ro the
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been set ( April 2013 ) and it might occur that references and
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