Well folks, today the JRC-1 project reached a major milestone: the design is complete, and parts and PC boards have been ordered!
I should to have everything in my hands in about a week, and with some luck, a working assembled board a few days after that.
Ordering PC boards is always a bit nerve wracking for me. One can never be 100% sure that a board is going to work until you get them back from the fab house and try assembling one. In addition, the final JRC-1 board comes in at 200×120 mm, which is considerably larger (and more expensive) than any of my previous designs. Still, I am very relieved to have finally hit this milestone, and assuming no major problems arise with the design I can shift my focus to creating the BIOS and operating system.
Over the next few days I will be copying most of the information from my private JRC-1 planning document over to the JRC-1 home page. This will include information such as the memory layout, component information, and details on the expansion slots and user port. Stay tuned.
I’m happy to report that the first build of COLE-1+ is up and running! JLCPCB created some beautiful boards and delivered them almost exactly a week after I put in my order. Here’s a photo of the assembled board:
There were only two fixes I had to make to the board after delivery. One is to add the missing pullup resistor on the ACIA IRQ line that I mentioned in my previous post; the other was a bodge wire to bring the A11 address line to the GAL. With those two fixes the board works exactly as expected.
Not only does this board run its original firmware just fine, it also runs a slightly modified version of the COLE–2 firmware, and this is the firmware version I am going to use going forward. My plan is to make this a universal BIOS for all of my future 65816 builds. This will allow me to continue development on the firmware while I plan out and design JRC-1.
In the end I am very happy with this build. I may do a re-spin of it down the road to correct the two errors I had to correct, and possibly add a power switch, just so that I can turn the unit off to pull the EEPROM without having to disconnect the USB serial cable. But, for now I’m going to concentrate on the firmware and on the JRC-1 design.