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I've not really been looking at any forums (fora?) over the past few months. Between holidays, some (holiday related) travel and such (i.e., helping Mom), there's been little free time. I've also been working on one of my cars, getting it ready to sell, so that's been a ton of my free mechanic time put to good use... and ran the lift a lot too.
In any case, with all of that behind me, I'm slowly getting back to my 8-bit projects (yay!) I've made some updates to my C02BIOS supporting the 28L92 DUART and the Microdrive. This is now quite solid and has good performance. I also finished a beta version of a utility program that will setup the DS15x1 RTC and also allow quite a bit of function for testing and examining the MicroDrive, which can easily be used for any IDE device as well... as the MicroDrive is the last of the format, meaning it uses a 35-pin PATA interface and is 3.3V only, 6GB size. My initial prototype of a 3.3V system has been functioning well, so it's time to move to the next iteration of the design.
This is where things get interesting. I already have my CMOS version of Rich Leary's DOS/65 running on the 3.3V system with the MicroDrive. However, like CP/M, it is limited to an 8MB drive partition and up to a maximum of 8 drives. This maxes you out at 64MB of storage. Granted, that's a lot for an 8-bit machine in the grand scheme of things, but somehow I want to be able to use more of the 6GB space.
I've had an interest in Fuzix since the start of the project. Over the holidays, I picked up a RC2014 ZED kit and added the CF adapter and RTC adapter. Total of 6 plug-in cards... and it uses the 512KB banked memory card which has 512KB of SRAM and 512KB of Flash. Using the ROMWbW firmware, CP/M runs out of the box, so to speak. Next, I grabbed the diskimage for Fuzix for this hardware setup. Trivial in all... write the image (I used a 512KB CF card) and got Fuzix up and running without issue. Fuzix uses more of a Minix filesystem and supports up to 15 drives, each to a maximum of 32MB per drive. That's quite a statement for an 8-bit machine overall. Fuzix does require banked memory however due to it's size. But even at a 0.3 release, it is quite solid.
The next step.... for a 6502 build of Fuzix, you need a CPU card with the I/O window at $FE00. It also requires a 6522 for use as a system timer and will support a 16550 UART as a console. I'm in the process of putting together a couple RC2014 adapters: one being the CPU which will include the clock, reset logic and of course the I/O decode window. the second being a serial/parallel card with a 16C550 and 65C22. Once that's done, I'll be able to build up a Fuzix disk image and use the minimal amount of ROM code required, which is also on Alan's Github site.
I already put a build environment up for Fuzix. Using Ubuntu Linux, the CC65 compiler, Byacc and the usual build stuff, GCC, Make, etc. I had a handful of errors trying to build the diskimage. I put that info into the Github issues area and Alan just fixed that with a few other updates. After a bit more tweaking, I now have everything working... it outputs a 40MB diskimage file which can be loaded on an IDE device and hopefully will boot up and run, once I have the two adapters outlined above completed and working. Of course, this also requires a banked memory scheme, which is currently compatible with the RC2014 banked memory card, so the plan is to use something like thing for my next Pocket SBC v3 design.
We'll see how this works out... time to get to schematics and PCB layout tools.
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