Getting closer

I have fixed most of the video issues and can reliably boot into Apple ][ mode. I was planning on posting some pictures, but I got side tracked. I finished the 128K memory code and also finished the Floppy disk emulation. I say finished, but it really is not finished until it is tested. I have done almost no testing on any of these new features. The memory I can test using an assembly language program. I am working on it now. When the memory code has been tested and debugged, I need to switch over to the Apple IIe ROMS. This will give the 80 character display capabilities. The floppy can be tested when I am able to boot ProDOS from another device. The Floppy took one half of the available RAM memory. I did not realize it would take so much, but I decided to emulate a dual drive system, since some games require both drives to play. If the basic design works, the floppy will be independent of the CPU speed and still remain software compatable.

I have made some feature set decisions. I have abandoned the IDE/ATA controller. It was taking too much FPGA space for too little gain. I ran out of room on the FPGA when I had the code for both the IDE and the Floppy. The LPC bus Flash ROM I am using to boot the system can be made into a ProDOS read only file system. Since I already have this running, it will only be a minimal amount of software (no additional Verilog code) to make this work and I will be able to boot ProDOS. I found a guy on the internet that was using a serial port linked to a PC as a ProDOS drive. This will be much easier to transfer files from one system to another. Since I already have the 6850 running for the OSI machine, I will use this same 6850 and write the sector get and put that ProDOS requires. It maybe a little slow, but it gives me an easy way to transfer files from one machine to another. I will then have to write the PC code to make it work, not too difficult. So I will have 3 different types of drive controllers, LPC, Serial, and Floppy. And really, I have 384K (128K * 3) to be made into a memory card / ProDOS drive. That gives me 4 different types of controllers. I do not think I need the Compact Flash also. Besides, to get the ATA to work will require me to build an adapter to go from the FPGA card to the IDE to CF adapter.

As I have stated, I am running out space on the FPGA. But since I have almost everything finished, I am doing pretty well. The last feature to add is the joystick. I have an idea how to do it and be processor speed independent. But since I have minimal space, I am a little worried it may not work. This will be the last thing I work on. I should be able to get started on this in a couple of weeks.