Gotek USB in a CPC6128

[TotO]

On the Jeff's text file: "2 additionnals 4.7Kohms pull up resistors (+5V) are needed on SCL & SDA."
That mean, you have to:
- link the SCL pin to VCC through a 4K7 resistor.
- link the SDA pin to VCC through a 4K7 resistor.

That allow to force "high" the signals if nothing is connected.

[Beaps]

Hummmm

On the back of the LED there is SDA & SCL are they not used then?

Do I just connect SDA & SCL together then connect them to VCC on the back LED?

Little confused 

[TotO]

SDA to SDA and SCL to SCL are required to communicate. It is the serial connexion.
When done, add the resistors like explained.

[Beaps]

OK so SDA to SDA and SCL to SCL, the run another wire from SDA and SCL with a to the 4K7 resistor to VCC?

[TotO]

Yes. You can probably solder the two resistors from the SDA and SLC pins, to the VCC pin.

[Beaps]

ahhh still nothing just this

[Bryce]

That's what they show if they haven't initialised properly. How long are your SDA SCL wires? Is the LCD being powered up at exactly the same time or earlier than the Gotek?

Bryce.

[gerald]

Hummmm

On the back of the LED there is SDA & SCL are they not used then?

Do I just connect SDA & SCL together then connect them to VCC on the back LED?

Little confused 

You have to connect the resistors as pull up on SDA/SCL :
for SDA :  one side of the resistor on SDA pin, the other on VCC.
for SCL : one side of the second resistor on SCL pin, the other on VCC

SDA/SCL are connected directly to the display.

[Beaps]

This is how I got it now... same outcome

[Bryce]

Those two pull-up resistors can potentially short out across the other pins and even some uncovered vias on the PCB. Make sure they aren't touching off something that they shouldn't be.

Bryce.

[Beaps]

It's ok I 100% made sure the don't touch when testing

[Yrouel]

First I'd clean that big solder blob that seems to be touching the square pad next to it.
If the connections are ok and it still doesn't work might be an address issue. Check if pin 1, 2 and 3 of the chip on the smaller board are connected to ground or vcc or nowhere (to number the pin, with the notch of the chip on top go counter clockwise starting from the top left pin which is 1).
If those pins aren't connected anywhere connect them to GND to fix the default address to 0x20 (or 0x38, depends on the specific chip variant). If that still doesn't work you might have to wait for an updated firmware from Jeff to support that I2C board variant.

[a7mag3ddon]

Are there different variants of i2C?

[Beaps]

After chatting to Jeff it turns out, the main thing I did wrong was leaving the digital display connected 

I removed the other display and bingo, works a treat.

Massive THANKS again to Jeff for patience and help

[Bryce]

Are there different variants of i2C?

No, it's a proper standard.

Bryce.

[Beaps]

Here is where I am so far...

[KaosOverride]

I have found some code to use an ATMEGA8/16 as a text OSD overlay, looks like can be attached to the video DIN internally. The ATMEGA8/111111116 has i2c bus so maybe a 2x16 display simulation can be coded if the ATMEGA can manage it.

[Bryce]

Very nice work beaps. I'd recommend one of these: LCD FRONT 12: LCD-RAHMEN für 2x 16 Zeichen, schwarz bei reichelt elektronik
They give a very professional finish and protect the screen too.

Bryce.

[Beaps]

Oh wow yer thanks Bryce

[Bryce]

You might find it cheaper locally or on ebay. They have their own glass, so be careful to order one with clear glass (They come in red, green and blue too). The hole needs to be about 1mm wider on all sides, and the bezel hides the fact that cutting a perfectly straight edge in plastic by hand is impossible

Bryce.

[CraigsBar]

You might find it cheaper locally or on ebay. They have their own glass, so be careful to order one with clear glass (They come in red, green and blue too). The hole needs to be about 1mm wider on all sides, and the bezel hides the fact that cutting a perfectly straight edge in plastic by hand is impossible

Bryce.

hmmmm. Might consider that and fit my hxc internally in my plus. @Bryce, do I have to reinstate any cut tracks to achieve this, and set the external port to drive b only?

[Bryce]

What cuts have been done to it? Or are you talking about the 464+ I upgraded for you?

Bryce.

[CraigsBar]

What cuts have been done to it? Or are you talking about the 464+ I upgraded for you?

Bryce.

yep, that's the one. I did not spec an internal hxc because I don't truse my case cutting skills lol.

[Bryce]

On the 464+ There'll be a wire from the internal header to the floppy connector on the PCB. You'll have to remove this wire completely and re-connect the connectors pin to the appropriate hole in the PCB. Then the internal header is back to being A: and the port will be B:. Alternatively you could just add a switch to swap these signals and then you have an ABBA switch.

Bryce.

[CraigsBar]

On the 464+ There'll be a wire from the internal header to the floppy connector on the PCB. You'll have to remove this wire completely and re-connect the connectors pin to the appropriate hole in the PCB. Then the internal header is back to being A: and the port will be B:. Alternatively you could just add a switch to swap these signals and then you have an ABBA switch.

Bryce.

You put an abba switch in it anyway for me.... alternatively I could wait until you have finished Gryzors Mist, and your Plus laptop then post you the Plus and the HXC and ask nicely to fit it internally with the existing abba switch for me. LOL


and one of those covers over the screen would be great too


Craig