Fixed typo, added BOM notes.

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Unknown 2019-01-14 15:04:31 +01:00
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@ -4,7 +4,7 @@ The original Apple 1 computer had circuitry for displaying data on a monitor as
Via the Arduino Nano we can communicate with the computer, the one you'¨ve just built, by using your favourite terminal emulator program such as PuTTy, SecureCRT or similar over the serial interface provided by the Nano. The Nano will of course need some software running on it, you'll find that in the form of an Arduino sketch called "[PIA Communicator](https://github.com/tebl/RC6502/tree/master/RC6502%20Serial%20IO/pia_communicator)". This is a rather basic version of that is intended to get you started with something that is easy to understand, thanks however to the wonders of the Internet and collaborative forces of Github you can find a much improved version of it on [https://github.com/jblang/pia_communicator](https://github.com/jblang/pia_communicator).
The RC6502 computer, more specifically this module or the one integrated into the (SBC)[https://github.com/tebl/RC6502-Apple-1-Replica/tree/master/RC6502%20Apple%201%20SBC] version of it has an IC called a PIA (Peripheral Interface Adapter) on it. The PIA has two ports and when Wozniak his original Apple 1, he dedicated one port to video output and the other to keyboard input - both of those functions we've replaced with our Nano, but to keep things original we've kept the actual PIA to keep things authentic. A 40-pin headers in addition to a couple of pull-up resistors have been added to the board so that one or both of these can be later replaced with actual hardware.
The RC6502 computer, more specifically this module or the one integrated into the [SBC](https://github.com/tebl/RC6502-Apple-1-Replica/tree/master/RC6502%20Apple%201%20SBC) version of it has an IC called a PIA (Peripheral Interface Adapter) on it. The PIA has two ports and when Wozniak his original Apple 1, he dedicated one port to video output and the other to keyboard input - both of those functions we've replaced with our Nano, but to keep things original we've kept the actual PIA to keep things authentic. A 40-pin headers in addition to a couple of pull-up resistors have been added to the board so that one or both of these can be later replaced with actual hardware.
You have several options for which particular type of PIA to use, there is the MC6820, MC6821 as well as the newer W65c21 that are available. The ones I've had most luck with, and to me feels the most authentic has to be the MC6821 by Motorola - a slightly newer design than the original MC6820, but it's more abundantly available for purchase while still featured in most older computer design books so that is the one I prefer to use.
@ -18,6 +18,8 @@ point for ordering PCBs, the schematic is also available in
[PDF-format](https://github.com/tebl/RC6502/raw/master/RC6502%20Serial%20IO/export/RC6502%20Serial%20IO.pdf). You can refer to the BOM below for a list of suggested components to use, part numbers in parenthesis are optional and is not required.
# BOM
These are the components needed to put together your very own Serial IO-module for the RC6502 computer, should be able to get most from your favourite parts supplier though the older PIAs I had to purchase via AliExpress/ebay since they aren't stocked anymore by the other monopolies (atleast where I live). For the pin headers, both male and female - if you can't find the exact pin count, just buy the longer versions and snip/cut off the parts you don't need (get extra in case of accidents, and don't cut yourself either!). Part counts in parenthesis are to be considered optional, so if you don't have any plans for them then they can probably be left out until you need them.
| Reference | Item | Count |
| --------- | ------------------------------------- | ------ |
| PCB | Fabricate yourself using KiCad files | 1 |
@ -34,3 +36,5 @@ point for ordering PCBs, the schematic is also available in
| JP1 | 1x2 right angle pin header, male | 1 |
| SW1 | PCB momentary push button | 1 |
| Nano | Arduino Nano with data cable | 1 |
If you would like to have a copy of one or more modules, what you'll need to do is zip up the contents of the export directory for each module and give that to your favourite PCB fabrication plant. Personally I prefer to use [PCBWay](https://www.pcbway.com/setinvite.aspx?inviteid=88707), each module has been designed to fit inside the 5$ dimensions. Use the link provided when signing up to support this project!