Replica 1 TE Users Manual
© Briel Computers 2007 page
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My next step was to add some address decoding so the replica 1 accessed the I/O chip 6821 PIA and ROM at
the same addresses the Apple 1 used. I used a 74LS138 to decode addressing for both the 6821 and an 8K
EEPROM. I also made sure that the space for BASIC (E000-EFFF) was EEPROM so BASIC could be stored in
ROM.
I now had a core CPU section replicated from the Apple 1. I still had no video section and I needed to build a
prototype. After some delays I finally built a prototype on wire-wrap and tested it. It didn’t work. I needed to
troubleshoot the board but my free time was very hard to come by and the replica sat on the shelf for a few
months.
In November of 2002 I received an email from Leander Kahney of Wired Magazine. He had been reading on
the replica project and wanted to interview me. My first reaction was, “Why me?” I had no idea the cult
following that Apple had. I really was fond of Apple since the beginning but Apple has such loyal owners and
they love everything that involves the history. So, here I am on the phone with Leander as he is asking me
questions about why I am doing the project, and when will it be completed and what will I be selling these for?
What? I didn’t have the heart to tell him that the project is on the self, that I have no idea what to sell these for
even if I had a working version. Little did Leander know that because of him, the replica 1 was pulled off the
shelf and completed. I started from scratch, and created a breadboard version of the replica 1. This time it
worked… Sort of… Well, the I/O chip, the 6821 was sending binary code for a “\” which means that the replica
was seeing a reset and the Woz monitor was trying to output a “\” to a TV monitor. Now I needed a video
solution.
Right after the Wired article was released, I received an email from Greg Glawitsch. He stated his interest in the
project and said that he had a “down and dirty” solution to the video problem. His answer was to use a
microcontroller to output TV text like the video terminal section of the manual. He offered to help by writing
the firmware to do this and it would only require a couple external IC’s to help the microcontroller. Wow, 3
chips to do what took about 24 on the Apple 1. This was perfect. And with some work with Greg, we had a
working video section.
In August 2003 the first of the replica prototypes were being made. I didn’t have a name for the board yet and
simply called it A1 replica. I also just put my initials on the board with the year 2003. Shortly after my first
prototypes were built, I created Briel Computers. At this stage my old high school friend Chris contacted Woz
through his webmaster asking for permission to use the Apple 1 code. His approval of the project prompted
another Wired article.
In October 2003, the first replica 1’s was being built and thus completing a 20 year old dream to design and sell
my very own computer. Thanks to Woz for being such a strong influence and great guy to give the ok for this
project.
Vince Briel