mirror of
https://github.com/TomNisbet/TommyPROM.git
synced 2025-02-19 14:31:06 +00:00
23 lines
1.0 KiB
Markdown
23 lines
1.0 KiB
Markdown
# Unlock Ben Eater Hardware
|
|
|
|
|
|
|
|
Utility to unlock 28C256 Software Data Protection (SDP) for the
|
|
[Ben Eater EEPROM](https://github.com/beneater/eeprom-programmer)
|
|
programmer design. This hardware is similar to the TommyPROM hardware, but it uses
|
|
different shift register chips and different pin assignments.
|
|
|
|
To meet the
|
|
[timing requirements of the SDP unlock](https://tomnisbet.github.io/TommyPROM/28C256-notes/),
|
|
this code uses direct port writes
|
|
to set and read values on the data bus. It will work with Arduino Uno and Nano hardware,
|
|
but would require changes for other platforms.
|
|
|
|
**NOTE** that this sketch **will not** work on TommyPROM hardware. It is included here
|
|
to help people with locked chips who are using the Ben Eater design.
|
|
|
|
|
|
|
|
The timing trace shows the tBLC for the bytes of the unlock sequence within 65us, well
|
|
within the required 150us in the datasheet.
|