RIBBBIT65 on Mini-ITX: The Pre-Dawn Chill

RIBBBIT65 on Mini-ITX: The Pre-Dawn Chill

Good news, everyone! I've taught the toaster to feel love!

Also, the design of r0.1 of the Mini-ITX version of the RIBBBIT65 is frozen!  After six months and at least a dozen "clear all tracks" re-works, switching the WDC chips from PDIPs to PLCCs to QFPs, changing all the TTLs and passives to SMT and a myriad other second-guessings and but-what-ifs, first light is in sight.

The board's ID block

The board has 1 ACIA (the serial console, as socketed PLCC), 3 VIAs (2 general pupose, and one "internal" for the LCD character display - as QFPs), and support chips to cover power, reset, PROM select, and IO select.  There are 5 DB9 serial ports and 2 DB25 connectors providing access to the general pupose VIAs.  ACIAs (with MAX232s) are available on "Serial Twin" daughter boards, and the system "core" is provided by a mezzanine board.

PROM and IO select signals, as well as IRQ lines for integrated peripherals are available on headers.

The top of the board, favoring the rear IO

The board is powered by a standard 24-pin ATX-style connector, and has an ATX-style pin header to support power and reset switches, and a power LED.

The top of the board, favoring the front edge

If everything goes according to plan, I should be able to just drop this board into one of a handful of Mini-ITX cases I have around, and cook.

The "core mezzanine board" has already been designed, fabbed, and assembled, and I'm pretty sure it's good to go.  The "serial twins" cards have been fabbed, and I've assembled one of them, so that's a plus.

"Core mezzanine board" with EEPROM address decoding

"Serial Twins" card with 2 MAX232s and PLCC sockets for 2 W65C51s 

...so, now, it's off to review proofs, fix any issues, and then off to manufacturing!

The back of the board, favoring the rear IO

I'm planning on streaming the assembly of this board, as this will likely be quite the educational experience for me, and hopefully you can learn something too, or at least be entertained by my hamfisted efforts!  Check out the RIBBBITN3RDing YouTube channel - subscribe and click the notify bell if you'd like to catch the streams live.  Eventually, I plan to edit the assembly down to a single video with boring bots cut out and tedious soldering sped up... but that will likely take a while.