quote:

---

Originally posted by SimonZ

Hi to all, i'm new.
I have the GQ-4x4 and would like to use it to read the chip in question, specifically the HD6473308CP (84-PIN PLCC not windowed).
The chip is NOT officially supported and requires an adapter that allows you to read the PROM inside it like a normal HN27C256 which is instead supported. The manual on page 244 shows the pin-to-pin connection diagram so I decided to build one myself.
When I go to read the chip, only 00-00 appear in the buffer up to the address 3FFF and then from the address 4000 onwards all FF-FF. What I see should correspond to what the manual says (in fact the chip only has 16KB even if it reads like an HN27C256 which has 32KB). Given that the chip certainly contains data, the adapter has no short circuits and the signals arrive correctly at the respective pins, what I'm wondering though is:
What am I missing? Could I simply solve the problem with the 9Vdc external power supply that I'm missing or do I really need an ad hoc adapter (for the H8/534 I actually see a capacitor and a resistor)? Do we need official support perhaps for some algorithms?

MANUAL
https://drive.google.com/file/d/1UMEnFIMv2WEkx3bDwn_fQS3wusgngwQG/view?usp=drive_link

My Adapter


534 Adapter

---

quote:

---

Originally posted by SimonZ

Sorry in the picture 5 connections are missing, I took the photo during production... it's just an example to understand the DIY level but in the end 42 wires are connected to all 28 pins like a manual

---

quote:

---

Originally posted by SimonZ

Update:
I purchased a 9Vdc power supply but the problem was not resolved. I suspect the chip is faulty or specific support is needed for this model and/or its adapter.
I made the request from the program but I imagine it won't be a short thing as long as the proposal is accepted...

---

quote:

---

Originally posted by SimonZ

Yes you are right anyway my doubt is:
Why if the H8/534 can be read as HN27C256 like the H8/330 for the 534 is there a resistor and capacitor in the adapter?

---

quote:

---

Originally posted by SimonZ

I've found an explanation perhaps..
I think my adapter works properly but the H8 it was programmed using a security features that I didn't know he had.

This is the application notes where explain this option (pages 21-22-23 of the pdf)
https://drive.google.com/file/d/1n_DSOA58NnEMlbuHQ3jFN-p5cL-HlcNh/view?usp=drive_link

If this feature is enabled, user will read only "00" exactly what happens to me.

So the new question now is:
Has anyone had similar experiences? Is it possible to bypass this protection somehow?

---

quote:

---

Originally posted by SimonZ

Ok, after several searches I found an application notes manual that talks about read protection. It is possible to protect the contents of the chip at each individual address by enabling this function. If used, anyone who tries to read the memory will only get pairs of zeros just like what happens to me! Since zeros appear exactly up to the last programmable address, I assume my pin-to-pin adapter works fine but the contents are protected.

---