Yesterday I was taking apart an old dinosaur computer monitor to salvage parts when I stumbled upon an Intel 8052 MCU. I thought it would be fun to try to program it so I went online and found an assembler and an 8052 simulator program and now I have everything I need to write and test programs for this MCU. The only thing I need to figure out now is how to upload the programs from my computer to the MCU. I don't think I see any pins on the datasheet that I could plug an ISP Programmer into but please correct me if I am wrong.

Here is the datasheet: http://www.keil.com/dd/docs/datashts/intel/80xxah_ds.pdf

I am not completely sure but I just saw elsewhere on the internet that my MCU may not be reprogrammable because it was programmed right out of the factory. Not sure though.

Many years ago, I worked with the 8032 processors. I don't remember the details but I do recall having the programming on external eproms. The 8052 has internal ROM but I don't have that info.

I think that they are permanently programmed, whereas the eproms could be erased and reused. I also think the 8052 is selectable for internal/external ROM or eprom use.

Thanks mongo! Sounds to me if I wanted to program this thing I would have to learn how to hook up an external eprom and program that. I did find however that other companies like Atmel have made there own versions of this MCU that are reprogrammable.

You have to use the secondary functions of one port, along with 12Vpp on the EA pin to flash program the MCU. After it's flashed, it can then read off the internal or external memory using th address bus and a data port.

That is a really high-level explanation. But it gives you a place to start learning the 'how'. Find a better datasheet.

BM

Oh cool. So I guess it is possible. I'll have to look into that.

BobaMosfet, on page 13 of this datasheet under "Programming Algorithm". Is this what you where talking about. www.atmel.com/Images/doc0313.pdf

Same concept but I was looking at the full datasheet for the 80xxah. You can find it online, use google.

BM