I've read through all the posts, and I see many good ideas about the design of a 6502 PCB, but I see no ideas of what the PCB is to do. All the projects I've worked on before start with a problem to solve. The design then starts from there. I think we should discuss some of the ideas for usage of this design when it's done. Sure we all need RAM, ROM, and I/O (6522's & 16550). Some have mentioned a connector for a LCD display, a RTC. These are all nice. Suggesting them must have some idea of an application. Let's hear about these. Most all projects I've worked on have some kind of Operator Interface. The LCD commuicates from the Computer to the Operator, but how does the Operator communicate to the Computer ? Most designs I've done I've added a 74C923 to connect a 16 position keypad. This has taken care of most applications. On the Serial Port do we just want RS-232 ? I've usaually added RS-485, also. This allows longer links or networking in an industrial environment.

Let's hear what you want to do with it.

Ted

For me, the board will be a place to install all the 65xx chips I have laying around. I'm only "half-joking" when I say that.

I *may* use it as a 'home-control' CPU - let it control things around the house via X-10.

Or, I *may* use it as a platform to experiment with FORTH.

I definitely plan to get at least 2 of the boards, and plug them together PC/104 style. Not because I really *need* to, but just because it sounds cool.

The ideas about LCDs and keyboards are neat (and I may experiment with things like that myself), but I don't feel that they should be built-in features on our very first board project. The serial port with a little monitor code in PROM will give everyone what they need to expand on it in whatever direction they like. We all have PCs, and can run a terminal emulator program on it, thus giving us a useful 'user interface' to work with.

Pete

I mostly am interested in the design prodject because I've done everything BUT build my own little computer from discrete components and really want to make my own little 6502 computer for whatever weird tasks I can think up..

Ted,

To be honest, I don't really remember where the idea for this project came from. Pete McCollum was e-mailing me at the time this started and we were discussing it, perhaps it was his idea or mine. At least two other people had suggested it also at one point or another. Pete and I started playing with ideas and I made the project web page. I started getting regular e-mails from others about it so I opened the forum and this thread. I am starting to think the forum was a really great idea. It wasn't mine though.

There was never a purpose defined for the board, other than my description of it as a "general-purpose" board. It seems most people interested are going to use it as some type of controller, for a robot, home automation, a wind instrument, whatever. The basic idea was you could use it for just about anything, especially considering its expandibility.

I'm really not sure what I'm going to do with mine. I think that as an experiment I'm going to make twenty or thirty and teach a college class with them. By that time I hope to have enough reference material and even tutorials online at www.6502.org to make this possible. I'd say about 1/5 of the site visitors that e-mail me are students.

The original idea was that user I/O was going to be done through the serial port. You could use the monitor program (or anything else you're running on the board) through the serial port on a PC, then unplug the PC and the board can use the serial port for anything else also. Personally I think that an LCD and a keypad are too bulky to put on the board but would make a good stacked expansion card. I don't know if this opinion is shared but I suspect it is. One of the design goals is "small size". Nothing is set in stone though.

I'd like RS-485 also if it can be implemented simply. I worked with devices that use it but I've never designed anything with it.

I'm impressed with the volume of messages flowing through here and the regular visitors. Keep up the good work guys.
I'm sure this is going to be a great board when we're done arguing about it.

_________________
- Mike Naberezny (mike@naberezny.com) http://6502.org

Hello,

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I'd like RS-485 also if it can be implemented simply. I worked with devices that use it but I've never designed anything with it.

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I (as a student) have been working on an RS-485 transceiver project this semester, and I can tell you that it is MORE than easy to make an RS485-aware system. You only need a SINGLE chip, which does the same thing a MAX232 or 1488/89 are usually used to do: transport layer conversion. In this case, you need an RS-485 transceiver chip, and you connect the transmitter to the TX output of the UART, and connect the receiver to the RX input of the UART. This full duplex operation can be done entirely by a low cost chip by Maxim (The MAX488) which has only 8-pins and it works from 5V nominal supply with TTL input and output. However, this chip consumes quite a lot of power so it can be ommitted in systems which do not require RS-485. It's a really simple expansion though and it will not add discrete components to the design.

Regards,
Tennessee Carmel-Veilleux
veilleux@ameth.org

I didn't intend for the LCD & keypad to be mounted on the board, just connectors to connect them. But a seperate expansion board would be ok,also. We'll have to see what size the board works out to be.
Ted

Thats exactly what I had in mind for implementing the RS-485 interface. It would take just a couple jumpers to select either RS-232 or RS-485. I worked on a project last year that had 32 Stepper Motor Controllers on a RS-485 network. Ths MAX488 was used on each controller for the RS-485 interface.
Ted