[9] Design Project

[gregqci]

Hi
I just wanted to mention that I have been using WDCs 65C02s and 65C22s. I also managed to purchase their SDS through my employer. The WDC65C02 and 65C22 is the cream of the crop.
It would be very helpful if they would sholder a little support for the packaged chip user like they do the embeded core user.

gregqci

[gregqci]

Hi
I just wanted to mention that I have been using WDCs 65C02s and 65C22s. I also managed to purchase their SDS through my employer. The WDC65C02 and 65C22 is the cream of the crop.
It would be very helpful if they would sholder a little support for the packaged chip user like they do the embeded core user.

gregqci

[Mike Naberezny]

Hi Greg,

This support is coming. Enough people asked me about it that I am negotiating becoming a distributor for WDC parts in small quantities for hobbyists and students. I'll let you know more as things unfold.

[Mike Naberezny]

Hi All,

I'm slowly becoming acquainted with the EAGLE layout software thanks to the help of Douglas Beattie. By now you should have had time to download the EAGLE package, if not it is available from http://www.cadsoftusa.com .

The PCB Project page has been updated to include a link to download the schematic in progress: http://www.6502.org/pcb.htm . It is just starting and I expect to be working heavily on it in the next two weeks.

Also, anyone interested in building the PCB should take a look at http://www.6502.org/bulkordr.htm . I have made special arrangements to make a bulk order of 65xx chips from the Western Design Center. You can get the pricelist and check out the progress of the order on this page.

Have fun.

[Mike Naberezny]

Hi All,

I have been steadily increasing my skills with the EAGLE editor and expanding the schematic in progress. You can always download the latest version from the PCB Project Page.

Let me pose a question: does anyone actually plan on using the 24-pin 2K devices (6116, 2716)? If not, only supporting the 28-pin (8K and 32K 6264, 62256) would simplify the schematic and PCB.

[saipan59]

Sure, I say go ahead with 28-pin only.

Pete

[paulrsm]

Please try to leave enough room around the ROM socket so it can be a ZIF socket.

I am coming into this discussion very late, but for a first design it does seem too complex. Why not 1 or 2 MHz, 32K SRAM using a single chip, 16K or 32K ROM using a single chip, a serial port at 9600 baud, a reset button, and PC power supply connectors? Not expandable in any way, but just a very simple first effort?

Paul R. Santa-Maria

[Mike Naberezny]

Paul,

Douglas Beattie has already created a board like you are talking about, it's called DIY-6502 and you can find it linked in the "Homebuilt Projects on the Web" folder on www.6502.org. He even has a PCB for it now!

Although our circuit board will come ready to solder on the expansion connectors and buffers, it's entirely up to you to add them or not. This way you can make it as simple or complex as you like and it fits well as a general purpose board.

We spent a lot of time arguing and discussing the board and that's how it got up to this level of complexity. See the past 100 messages or so <grin>.

There will definitely be enough room for a ZIF socket, I plan to use one myself.

I've made the design so that it accepts a 28-pin EPROM or SRAM which greatly simplified things for me. If anyone needs to use the 24-pin devices please let me know and I'll see about adding support for them, but if nobody speaks up I won't do it. The 28-pin devices are so common I don't see how anyone could have a problem getting them.

[leeeeee]

Hi Pete,

I know this is a bit old but ...

>>
7. INPUT and OUTPUT should be vectored. This makes changing the I/O device simple.

Please elaborate.

<<

This is easy. You set up a table of word pointers to useful I/O routines in RAM, routines such as chrin and chrout. These pointers are initialised at startup by the monitor and are paticular to that implementation of the board. So you've written an application and you want to print some output you call the output routine by doing an indirect jump via the vector.

So now I want to try your application on my board but my output isn't via the RS232 port it's to a 256x128 graphics LCD (I can dream can't I?). No problem, your app. calls my output routine via the vector in (the same place) in RAM and the app. code is none the wiser. The same can be done for input, RTC functions, disk drives and the like.

It also means you can redirect input or output by changing the vector so when you type SAVE in BASIC for example it first changes the output vector to the tape device, then executes a LIST command and then changes the vector back before quitting and a list of your program has just gone to the tape.

It's not really a hardware consideration but if it were adopted as policy for the monitor then applications developed would be more portable amoung different hardware.

Lee.

[saipan59]

OK, I'm with you now...
Originally, I thought you were talking about some hardware thing, which is why I didn't follow you.

Pete

[Mike Naberezny]

Hi All,

I know that I haven't been posting in the Design Project thread very often, but I have been working on the schematic in the EAGLE editor. Unfortunately in the version I have there is no easy way to export the schematic to a JPEG or GIF image to share in the forum. However, I'll convert the working schematic to one of these forms manually and post it in a day or two so we can all discuss it.

Best Regards,
Mike

[saipan59]

How about doing an Alt-PrintScreen to capture the image?
Then you can crop it with a graphics tool, etc.

Pete

[RichCini]

Mike:

What I like to do is print from my EDWin CAD program to the Adobe PDF driver. I have Acrobat Exchange, which enables the creation of PDF files. The PDF driver looks like a printer to Windows, so you can "print" to it. I then print-out the PDFs.

I had to do this originally since the print engine in EDWin crashes frequently, so I didn't want to go through the hassle of running EDWin if I needed another copy of the schematic.

Rich

[RichCini]

Mike:

What I like to do is print from my EDWin CAD program to the Adobe PDF driver. I have Acrobat Exchange, which enables the creation of PDF files. The PDF driver looks like a printer to Windows, so you can "print" to it. I then print-out the PDFs.

I had to do this originally since the print engine in EDWin crashes frequently, so I didn't want to go through the hassle of running EDWin if I needed another copy of the schematic.

Rich

[Mike Naberezny]

Rich,

Thanks for the tip! I'll look into it. I am just now getting started with the Adobe Acrobat program.