The Sinclair QL Forum

Have you got a picture of the chip to see what the label looks like?

You did mention the possibility of them being suspect...


With a bright light the text is visible


IMG_5047.jpeg


The K prefix seems to be used by several manufacturers - Not sure on the other codes under the part number ...

Have you got a picture of the chip to see what the label looks like?

You did mention the possibility of them being suspect...

The scanner has thrown up an issue with the AT24C256

It shows as both &54(&A8) AND &5C(&B8), confirmed as when unplugged both devices vanish

&54(&A8) works fine with both test programs

&5C(&B8) corrupts the end of the "page test" text
I thought maybe it was writing to Minerva, but on checking ...

So that Humidity and temperature device offers 2 modes - one using clock stretching (the hold commands) and one that doesn't use clock stretching - In the latter - you kick off your command to do the read, but then your program and the I2c bus are free to do other things, you come back at some point ...

I've been looking at that bit of code in Minverva quite a lot - After the Autovectors - there is basically a block of code to do the redirection of the vectors that are supported in Qdos, then the code to display the logo. I think it might be possible with some careful thought and adjustments to ...

So for the AT24C256 device :

And the PCF8583 device:

Meaning if A0,A1 and A2 on the NVRAM are all grounded, and A0 on the RTC is grounded - then they are using the same address - which explain the contention you were seeing Tony.

I think the address is correct - and it's the bottom bit of the byte that selects whether reading or writing, the next bit in is the selectable address (A0 or A2) that it can operate at.


The Mivera manual says the following:

Thus to write $1234 to location $56, the following is sent:
<start ...

I think the address is correct - and it's the bottom bit of the byte that selects whether reading or writing, the next bit in is the selectable address (A0 or A2) that it can operate at.

The expandability is that I intend to support up to 1GB addressable range.
Not possible due to QLiberator abusing the upper three address lines. 512 MB is maximum.


Yes - 1GB would be possible if only the top 2 lines had been clobbered / usurped - but 3 address lines leaves you with 2^29 - so ...

Is the information about what it relocates on what platform documented somewhere - which was basically the question I was asking.


For some of the modules, it is obvious (like that the vector table needs to go to $0), for most, the only (and best) documentation is the source code. (Have a look ...