After other projects, I had to build my main childhood computer: the Apple][+.
My Apple][+ clone was designed under the Baffa-6502 platform on which I implemented the Apple-1 clone and It's a natural continuation of the previous project. I spent some time studying the Apple][ project to simplify it as much as possible, without losing any of the functionality of the original computer.
Baffa-2 is an educational and personal project with the aim of understanding how computers work through 80's 8-bit commercial machine designs. It has a modular concept (like RC2014) and boards that can be combined to develop your own design and configuration.
I decided to use a Mark Aikens' VGA Board in my homebrew project (https://github.com/markadev/AppleII-VGA) to simplify (a lot) the video generation circuit proposed by Wozniak to generate NTSC video and also have VGA output.
The AppleII-VGA card works on both AppleII+ and Apple//e, but generates 80-column mode only for apple//e. Last week, I was studying how to emulate the Videx Videoterm board to provide 80-column mode for Apple II computers through Mark's project.
So now, my homebrew appleII+ and my old Apple II+ machine (an Exato Pro CCE - Brazilian AppleII+ clone) can enjoy the wonderful world of 80 columns video modes via VGA output :D
Last week, I finally received the slot expansion I ordered in the last week of october. (The postal strike and slow postal service are Christmas traditions in Brazil). There are two cards I need to order and I'll be using from my original apple][+ - Saturn 128k Ram and Softcard (CP/M Z80).
This is how it looks using the first version of my backplane. (I decided to rotate the connector on the first rev.)
Meu primeiro teste foi tentar rodar o CP/M no meu apple][+ clone. Para isto, é necessário utilizar as duas placas (saturn 128k e Softcard/Z80):
...and now I can enjoy games that request 64kb or more like "Where in world is Carmen Sandiego?"
For this last picture I assembled another backplane (rev.4). The expansion was designed to be connected behind the backplane.
At the end of last October, I requested the slot expansion that allows me to connect apple2 cards to my project. However, the versions of boards compatible with the baffa-2 bus that I ordered in mid-November arrived much earlier. This sometimes happens, thanks to Brazil's inefficient postal service. The boards I ordered in October sat idle for a month for no apparent reason... (and are still in delivery on dec 12).
The good news is that the 3 boards made for the baffa-2 bus have been tested and are working: DiskII Interface, Grappler+(Printer) Interface and SuperSerial/Wifi Interface.
These are my first tests of my new set of boards to recreate an Apple][+ computer. For now, I'm loading programs via the cassette interface only. My next goal is create pcbs for softcard, printer interface and drive interface. Using the drive interface I'll be able to load programs using floppyemu (for example). I also designed an expansion to use common apple cards.
ps: I'm using an old backplane - the same I did on apple-1.