Replica 1 TE Users Manual 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 © Briel Computers 2007 page 4