All --

I've made some additional enhancements to the V2.6R3 board (now calling it V2.7R0). Among the additions from the last turn:

* Added: Programmer's "panic" button via the NMI input; reworked NMI handling (no wired-OR)

* Commodore/Atari-compatible joystick interface

* Text video output using Daryl's one-chip video solution

* Slightly new board layout with connectors arranged differently so that it could be case-mounted

I attached a picture of the board plot below. I plan on doing a small order of boards which I should receive in a few weeks. If those work, I'll offer the extras up to the list.

On the software side, I've added a command for reading the joystick, and I'm making progress on the DOS commands.

Enjoy!

Rich

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org

All --

I received the boards and built one this afternoon and it works. There is one cosmetic issue with the placement of the video connector - it is set about 0.3" too far back from the edge of the board for the connector I selected. there may be other connectors that you could use.

If anyone is interested in a board, I have seven (7) available...they are available for $25 each plus S/H. Please PM me if interested.

The project page is here: http://www.classiccmp.org/cini/6502proj.htm

Thanks!

Rich

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org

Crack open some bubbly!


Is it practical to do a little routing on the board to compensate?

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Good job Rich!!

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Please visit my website -> https://sbc.rictor.org/

Thanks guys!

There are traces in the area between the connector and the edge, so you won't be able to route it. There are other RCA connectors with longer necks (on Digi-Key, search for CP-1421) that would minimize the problem for case mounting. Otherwise, I think everything else is good.

Rich

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org

I've been away for a week so I just read this. Congratulations.

The spreadsheet calls for the Rockwell 6551 ACIA. I assume that is because of the bug in the WDC version. Where is a good source for this part? I saw some new old stock on eBay, but it was fairly expensive.

Feel free to use which ever 6551 you have -- I only wrote Rockwell because that's what I had. I bought more on eBay. Search for seller "janegallant". I bought 10 for about $5 each.

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org

Rich, I ordered the parts from Digikey using the spreadsheet from your site. Thanks for including the part numbers as that made things so simple. They don't have the 6 pin DIN connector for the IEC in stock, but I figure I can get started without that. I also order the parts they didn't have from an eBay seller claiming to have some old stock of 6551 and 6522 chips. So I should have this put together shortly, then I'll need to program the EEPROM.

BTW The IEC interface was a smart addition to the SBC design. I've found out that there are SD2IEC converters available on eBay which makes adding mass storage to this design pretty simple. I don't miss cassette tapes or floppy drives, so they're one bit of nostalgia I'll pass on.

Thanks, Martin. I've been eyeing the SD2IEC as well, which is why I put that 2x3 connector on the board. I should probably order one as well.

On the DIN connector, I have gotten them at DK and also Jameco. DK may not always have the best prices, so for most of my projects I wind-up ordering from Jameco as well. Also, I've built up a stock of parts so I can time my ordering better.

Let me know how the build works out.

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org

For anyone unaware, the sd2iec firmware supports several c64 speed loaders. The source code (at sd2iec.de) is also available, making it feasible to set up a custom unit, even with the possibility of parallel transfers. One could also study the documentation in any of the speed loader source files, some of which contain detailed timing information.

store.go4retro.com (Hi Brain!) also has a custom sd2iec version called 'uIEC' commonly available.

-David

My Digikey order arrived last night and I soldered half the board. I then saw that SD2IEC header and realized you were way ahead of me. I also stopped when I got to the resistor networks, as I need to get the orientation correct. Both have a common pin and I'm guess it goes to the square plated hole which is on the left side of the board when viewed from the top for both the 3.3K and 10K networks. The common pin should be labeled on the network, but if I can't identify it my DDM can.

On bussed resistor networks, pin 1 is usually the left-most pin when facing the front (where the device markings are). There is also usually a dot near the pin. If there's any doubt, a DMM is the way to go. DipTrace usually uses a square pad to denote pin 1.

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org

Rich, thanks for the quick reply. I studied your schematics again and both networks have their common pin connected to Vcc, so I can verify all of this with a DMM before I put any chips on the board.

Again, my compliments on your modifications to the SBC design. I really like the idea of using a USB connector for power as I have a ton of those adapters around (every gizmo uses them for power). A standard DB-9 serial connector is good too because I already have cables to fit it versus making a ribbon cable to DB-9 connector. I don't have Atari joysticks anymore, but what would a retro computer be without one of those ports?

Thanks very much. On the USB, you make the exact case I did -- I have a ton of these adapters laying around. The next improvement could be adding an FTDI FT230X in place of the 6551 and MAX232, but that kind of violates the vintage-ness of the board.

On the joystick, that's why I added it I figured someone would figure out a way to write a character-based game that uses it.

_________________
Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.org
http://altair32.classiccmp.org