Using a W65c02 Simulator:

RAM Test

Overview:

A portion of the SBC30 code has been sliced and edited as  SBC30_TestRAM_01.asm to show a RAM Test function that is executed by typing "T" or "t" in the terminal.

The user is not prompted to enter anything.

Note: the Ben Eater 6502 design limits RAM to $3FFF. For more info try this YouTube link. As such the RAM test cannot test the A14 line to see if the value read is the same as the value written. Subsequently, that part of the code has been commented out and is documented in line.

Tester:

Oshonsoft 6502 Simulator IDE v1.41

Setup:

Setup your IDE as shown in the top screenshot.

Enable the Input Terminal with an I/O port of $5000.

Set the "One-Shot IN Value" to "54" for the letter "T".

Adjust the 3 Memory Editors to show addresses $0000, $1000 and $2000.

App Operation:

Using the FlashROM code, here are the only keystrokes needed to produce the adjacent lower screenshot:

- Press Reset button

- T

Breakpoints:

384, 400, 430.

Use <CTRL><F6> to get you to the breakpoints, use <F2> at each to get a feel what is occurring, then continue to the next BP using <CTRL><F6>.

IDE Operation:

If you wish to burn the code to flashROM, try this latest build: SBC30_0_R4.bin

Oshonsoft 6502 Simulator IDE

(Click to Enlarge)

Sim IDE

ASCII Terminal