Topic split from How to make a computer with only an Arduino Uno . [image] How to make a computer with only an Arduino Uno An Arduino is a computer. NOT all Arduino. Arduino UNO R3 does not support accessing external memory to store users transitional sketches for which the OP would be requir…

I was debugging FORTH words, FORTH compiles everything into bytecode, which in final instance run the basic words (where the code is in FLASH already). The step from one word to another is done by NEXT code, so I "hacked" this. So say I typed this on the keyboard: [image] gilhad: : ascii 0 BEG…

Okay, I see. I thought you had figured out how to single step the machine instructions without have to erase and reprogram the flash like the debug capability does on the 328. That results in significant wear on the flash and Atmel/Microchip warn against shipping any product that has been used that …

for that I used simavr+gdb or Disassembler for ATmega2560 (Arduino Mega R3) - both runs on PC and use its RAM, so no stress with breakpoints wearing something. For most of my purposes it was sufficient, so I debuged most of my SW there and for real HW I started with system, which mainly worked, exc…

Nowadays for $16 you can buy the Microchip XMIN board for the 328P and debug right on the hardware. They also use some kind of trick to limit wearing out the flash.

Most of the debuging was atmega2560 specific, like coordination of PG3 (A16) with PJ+PK(A0..15) and PD7 (/Read), PE5(/Write), PG5 (Select) for accessing external SharedRAM. The simple words usually worked on first try, or it was easy to see, what is wrong (2push instead one, 2pop instead 1, or vice…

[image] EmilyJane: I thought you had figured out how to single step the machine instructions without have to erase and reprogram the flash In the 8086, the single-step mechanism automatically saves the address of the next instruction to be sngle stepped on the stack. When the STEP key is pres…

[image] GolamMostafa: I sometimes wonder why the AVR development team could not implement a hardware-assisted single-step mechanism similar to that of the 8086, which would have avoided the need to erase and reprogram Flash memory during debugging. How would they have got the AVR to execute a…

[image] EmilyJane: How would they have got the AVR to execute an instruction out of RAM? Was AVR there at the arrival time of AVR?

Why are we still discussing RAM? A computer DOES NOT need RAM. As long as it is somehow programmable...

[image] GolamMostafa: Was AVR there at the arrival time of AVR? I don't know what that means.

Is an Arduino a computer?

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GolamMostafa July 1, 2026, 2:11am 242

I had followed the Guide Lines of Fig-1 of he 8051 Architectue to implemement Single Stepping in my 8951/89S52 Trainer (Fig-2) developed in 1999:

Figure-1:

Figure-2:

UNO R3: Developing a Single-Stepping Routine for ATmega328P without relying on JTAG Interface which contributes to flash wear

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Is an Arduino a computer?

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