I am designing an 8052 SBC that will be used as an example for tutorials such as those found on this site. I realize that many SBCs already exist and are available but so far I haven't found one that meets my design goals:

1. Implements the features that I want to cover in the supporting tutorial material.

2. Uses parts that are readily available so that acquiring the necessary parts will not be difficult for those that wish to build it.

3. Results in a design that is easy to build for the student or hobbyist.

4. Preferably isn't too expensive so that it remains accessible to the student and hobbyist.

Currently what I have in mind is an AT89S8252 40-pin DIP, external RAM, memory-mapped LCD and keypad, RS232, and probably an I2C (DS1337 RTC?) and some SPI device (to be determined).

I am not talking about the "8052 Atari" here. That's a separate issue. This is just a normal 8052 SBC I'm talking about here.

Since we've been talking about what should and shouldn't be a part of a modern SBC does anyone have any recommendations or thoughts as to what should be included? Remember the idea is to make the SBC as complete as possible so as to cover many hardware design and software concepts but at the same time to try to keep it as simple as possible so that it is still reasonable for someone to build one.

My query regarding the AT89S8252 ISP programming is in regards to this SBC. I want the SBC to be able to be programmed ISP by simply connecting a custom parallel cable directly to a 5-pin ISP connector.

Regards,
Craig Steiner