The first 65816 Board Arrives!

I have been on the road for work for a few weeks.
But I came home to a delivery from JLCPCB, which was my new V0 of the 65816 board!

Amusingly, in order to test it I will have to use the ROM from the “Hello World” program for the 6502. Since the 65816 boots up in emulation mode, I can run that right away and test if the LCD is working. Writing code for the Diagnostic LEDs should be fairly simple. And the 6551 should be set up the exact same as it was, so I should be able to test that with existing software I’ve written.

FlexATX Footprint for the 65816 board with LCD, Diagnostic LEDs, and ZIF for the ROM

Next will be to solder all the components and sockets on to the board. I’ve left the unused gates of the logic chips available, but tied to +5V through 10K resistor nets, so it shouldn’t be hard to use them.

There are 2 22V10-15 chips to handle memory logic, which I still have to figure out how to program. I have been using Digital for the design of the logic, and it says I can do JEDEC files, which the TL866 -II+ should be able to program for me, I just haven’t tried it yet.
The nice thing about GALs is they’re reprogrammable in case I get something wrong.

The Video RAM isn’t connected to anything, it was nice to have it on the board to make sure space would be there. The VIA_0, LCD and RTC will move to a daughterboard down the line. It will have a ribbon cable and connector so it can either be mounted in the wedge case or in a 5.25” drive bay. VIA_1 currently drives the diagnostic LEDs, but had plenty of unused pins and in the end may not even need to be there at all? I don’t know. It’s just a tool for now.

The Diagnostic Header on the upper left will not be in the final version, in place a third DIN41612 header will be there instead. All of the same signals are available on the cards, so it will be trivial to make a diagnostic expansion card.

For the 7805, I made a heat dispersion plane, but in the future I hope to move it farther away from the IO Backplane so I can use a standing heat sink.
It might not be the best idea, but I’m still new to all this, and I’m no expert.

Also, I never put my logo on this version! 😡