TRS-80 Arduino RAM Tester

This fork is modified to only test the 16k TRS-80 RAM (8041016A or NTE2117)

Forked from

This is a fork from Andre Miller's excellent DRAMARDUINO DRAM Tester for 41256 and 4164 DRAM available here: https://github.com/andremiller/arduino-dram-tester

Basic DRAM tester, outputs results to Serial, based on:

• https://www.insentricity.com/a.cl/252
• https://github.com/FozzTexx/DRAM-Tester
• http://www.chronworks.com/DRAM

Pinouts:

• DRAM pin -> Arduino UNO pin
• Pin 2 (DIN) -> A1
• Pin 14 (DOUT) -> 8
• Pin 15 (CAS) -> 9
• Pin 4 (RAS) -> A3
• Pin 3 (WE) -> A2
• Pin 5 (A0) -> A4
• Pin 7 (A1) -> 2
• Pin 6 (A2) -> A5
• Pin 12 (A3) -> 6
• Pin 11 (A4) -> 5
• Pin 10 (A5) -> 4
• Pin 13 (A6) -> 7

(Also connect DRAM supply pins, unlike original project, additional voltage rails are required and should be provided using a bench power supply) Pin 1 (Vbb) -> -5V Pin 8 (Vdd) -> 12V Pin 16 (Gnd) -> Gnd Pin 9 (Vcc) -> 5V

The number of address lines is configurable by setting ADDR_BITS

Changes to original code:

• Writes output to serial, displaying which row and col failed
• Times the tests and writes how long it took, just out of curiosity so you can calculate of refresh is happening fast enough
• Does pattern tests first (10101... and 01010...) because this identified failed ram faster for me
• Added a random bit write test