The Arduino Uno is not a very Retro style board but it is one of the boards that made microcontrollers available for the main public with a simple and free IDE and opensource hardware. I like using the AVR chips and nowadays a lot new designs of old retro computers contain an AVR chip to replace al lot of glue logic chips. There are even complete emulations of old system available on AVR chips and f.i. de KIM-Uno is a complete emulation of the very old KIM computer board on an Arduino Uno.
AVR is a family of microcontrollers developed since 1996 by Atmel and these are modified Harvard architecture 8-bit RISC single-chip microcontrollers. AVR was one of the first microcontroller families to use on-chip flash memory for program storage. The AVR architecture was conceived by two students at the Norwegian Institute of Technology (NTH) Alf-Egil Bogen and Vegard Wollan. Atmel says that the name AVR is not an acronym and does not stand for anything in particular. However, it is commonly accepted that AVR stands for Alf and Vegard’s RISC processor. The AVR 8-bit microcontroller architecture was introduced in 1997.
In 2009 the team that would become Arduino was formed with the idea of an accessible, affordable electronics development platform. This would eventually give birth to the Arduino UNO. That cheap little board went all over the world and one of oy successors was the Arduino Nano, that us internally the same but has a much smaller size. It isvery easy to use the ATMega328 (DIL version 28 pins) in an electronic design as standalone microcontroller and because it has build in flash and sram memory, 20 I/O pins and a lot of internal peripherals (like a build in UART) it can be used in all kinds of remakes of old computer designs.
When I develop I like to use an UNO or Nano as a drop in for the ATMega328 chip, here is the mapping of the Arduino Uno to the ATMega328 pins.
The same for the Arduino Nano, this board has the 32 pins atmega328 chip.
Have fun, regards, Hein Pragt.
