⌘ Apple II
Welcome to Apple II Projects page
Remembering the old days, remembering my first computers and first coding, a special place is left for my beloved Apple // c. In 1981 I received my first home computer, a Commodore VIC20. Starting in 1985, an Apple //c accompanied me for many years, through high school until early college years, until I decided to put it in a box. With the Commodore, in Italy, there was a fervid enthusiast community, and in the early years I could live and share my experiences with many friends, I remember that we exchanged the tape cassettes with programs and games and I made my first steps in BASIC programming; I was not, however, so lucky with the Apple II, it was not very popular in Italy, and only exclusively thanks any magazines and little else. In the years of high school, I rewrote all my computer programs, adapting the standard PC-IBM to that of Apple II. After many years I decided to re-boot my dear Apple // c, and so I decided to resume my old programs and experiments, above thanks to having discovered through internet a global community that has helped me rediscover my passion for the Apple II machines.
Unidisk Project
The project is based on the knowing of internal structure of Unidisk 3.5 drive, it use same HW of Apple II machines. It's a smart device built by controlled drive board powered by 65c02 mp @2.0 Hz with 2KB RAM and 8KB ROM plus 527 byte of I/O peripheral registers, all addressing by memory mapped method. The UniDisk 3.5 drives can use directly by Apple //c with 3.5 ROM (ROM version 0) or by Apple IIe or an II Plus using special interface controller card aka "LIRON card". The Protocol Converter is a set of assembly-lenguage routines built in 3.5 ROM or in Liron controller used to support smart external I/O devices (aka SmartPort), like UniDisk 3.5. The target of project is allow to use UniDisk 3.5 drive resource to process data in-line or off-line the Apple II like a "co-processor". The project evolved steps by steps:
1) Simply command and read information of UniDisk (DIB Device Information Block) using Protocol Converter STATUS Call;
2) Using Protocol Converter CONTROL Call to simply Eject disk;
3) Using Protocol Converter CONTROL Call (Set Dowload, Download, Run) to Download and Run a special 65c02 subroutine, and using STATUS Call to read the informations. This complex sistem allow to Dumping all UnidisK memory;
4) Use the seme mechanism of step (3) to download a simply routine to making integer operation at one or two Byte and read the relative results;
5) Due to UniDisk, less the I/O Disk routine in its ROM, is a bare metal, i decide to implement the Floating Point routine by using WOZ original routine, but I was need to write the converter program from WOZ routine to Applesoft routine. This allow me to execute FP operations;
6) Use the UniDisk FP operations to execute Graphics calculations, ... work in progress.