It's not a 65C02. Sorry! But I'm tickled how it turned out and I hope you don't mind me showing off. Lot's still to learn about PCB layout, like fills, etc. The spot for a Raspberry Pi Zero was more of an experiment to see if I could get the dimensions right for a Pi Zero shield and I am delighted that all the holes and edges lined up perfectly.

I'm looking forward to trying a couple similar 65C02 64K designs in a similar compact PCB form factor. Please wish me luck.

Happy Holidays and cheerful regards, Mike

A powerful combination of a minimal DIPpy computer, a PIC to boot, and a Pi for the difficult and modern interfacing. I like it! And the 1802 seems like a very interesting and unusual CPU too.

Looks really good. I have a couple of 1802 CPUs in the drawer, but I haven't figured out what to do with them yet.

So far I've used mine to blink LED's. Send it clock pulses and watch the TPA, TPB, SC0, and SC1 pins go high and low. I have plans to do more than that though.

edit: fixed a typo.

I gather the 1802 is very well suited to a mini front panel - you don't even need any firmware to be able to toggle code in, because it has a sort of DMA mode.

Yes, the CPU has a DMA mode. One of the registers increments the address bus, while the control lines deposit bytes off the data line directly into RAM. So you can build a front panel with about ten toggle switches, a push button, and a small amount of glue logic.

Nice work, Mike. I always get a grin when I see IC's mounted one on top of the other! Do you have plans to interconnect the Pi and 1802, or is the Pi included strictly as a mechanical test?

Good luck!

-- Jeff

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

So you're interfacing the R Pi to the 1802 via just the serial interface, and using the Pi solely as an on board VT100?

A Pi Zero is $5 - probably cheaper than a UART these days!

-Gordon

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--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

Thanks for the comments and interest, guys.

The Pi Zero is both a mechanical test and one of several terminal options. I'd like to try the "bare metal" PiGFX VT100 terminal emulation software (connecting the Pi Zero serial port to the yellow 3.3v connector on the 1802/5/6 board). I'd also like to try a full Linux install on the Pi Zero and a terminal emulation program with file upload/download capability.

Since I have a USB keyboard and an HDMI monitor already, the $10 cost for a Pi Zero + SD card seemed like a good option. I believe the Pi Zero can also produce VGA and NTSC video or drive TFT displays.

Happy Holidays. Mike

Sorry to be OT, but what's the software used for the schematic? It's the prettiest I've ever seen.

The Pi has HDMI video as standard. Standard resolutions from 320x200 to 1920x1080. (There are more and a lot of non-standard ones, but ...).

It can not do VGA on it's own - you need either a HDMI to VGA converter (there are several as well as HDMI to DVI), or a GPIO module which sits on-top of the Pi, however
that uses up ALL the GPIO pins..

Composite video (PAL or NTSC) is on-board as standard too, but on the Pi Zero it's not on a connector - you need to solder on a wire to your own socket to get access to it.

The DSI output on the Pi is somewhat limiting in-that from what I gather you need special code running on the GPU to drive it and there is only a small number of displays that work with it.

Hope that helps.

-Gordon

_________________
--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

I tested a little 4.3" LCD (NTSC/PAL) Monitor via the 2-pin 'TV' header on the Pi Zero before and it worked well, for its size.

VGA output using GPIO pins ties up a lot of pins so I just ordered one of these Chinese mini-HDMI to VGA adapters ($3.99 landed) to try out.

Microsoft Excel...

Really? I had no idea Excel had those capabilities. Would you mind posting your file so I can see how it's done? All I have ever used Excel for is spread sheets, tables and the graphing of data.

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Bill