6502.org

hi,
Just want to share my 6502 build with this forum. Many posts on this forum and other web sites has really helped me to put my SBC together. You can follow the build on my github repo https://github.com/maded2/6502. My next phase of the build is to work on graphic subsystem using the V9958 chip. Any comments and suggestion welcome.

eddie

Nice project Eddie.

Also, welcome to 6502.org

Looks good. Is that ZIF socket for the ROM soldered into the board?

Hello World! And welcome, Eddie. Nice photo log on github.

Correct, I made room on the PCB to allow ZIP socket for the rom.

eddie

Good idea. When I was developing the firmware for my POC V1.1 unit I wore out the ROM socket and had to replace it. Silly me, I didn't leave enough room in the PCB layout for a ZIF socket.

In a future build, you may be interested in a more compact type of ZIF socket. I will be using this one in future builds. It takes up little more room than a regular (non-ZIF) socket with the same number of pins. Data sheet attached.

thanks for the info. The fat zip socket is very cheap compared to this slim one. Custom PCB only cost 9USD for 5, so it's easy to change the PCB design.

eddie

In my SBC, I left enough room for the socket but not quite enough. When inserted, the bar wouldn't fully close because of caps, etc. Real bonehead move on my part.

So I just stacked the ZIF on top of a normal socket to give it lift.

On my next PCB, I don't think I will use ZIF at all. I think I will try an Arduino and program my flash memory directly. I like the idea of just uploading a binary file and not have to swap chips around.

I moved the rom cap to the side of the socket after v1.1 of the pcb to allow for the zip socket enough room to do its thing.

btw, Kevin Maier's Monitor can do in-circuit eeprom programming (have not try it myself), but here's the link. https://github.com/floobydust/65C02-SBC1

On my last C02 Pocket SBC board, I hid the bypass caps under the chips themselves. As I socket everything, I've been using Mill-Max open frame sockets, which allow for the bypass cap to be hidden underneath. I also do this for the EEPROM and simply use one or two additional stacked sockets to elevate a ZIF socket. This allows me frequent EEPROM removal during development and then I have 3 other boards (sans ZIF socket) that tend to run for extended periods (upwards of a year) for long term testing.

PS - thanks for the mention of my C02 Monitor. The 2.0x version is what's used on the C02 Pocket SBC, as it uses a Philips/NXP UART, instead of a 65(c)51. Your SBC is a nice layout... you might also want to try my CMOS version of Enhanced Basic at some point... it's a bit smaller and runs just a tad bit quicker. It also can run along with the C02 Monitor, as the Page zero locations have been changed so there's no conflicts.