REV B Amiga writes mod - step by step

[lotharek]

1. locate the board







2. bend up all legs of 23k256 ( dip8) - caut off all legs exept 4 - GND and put on the board so leg no4 goes into GND via ( check with multimeter !)







3. Use Your soldering iron






4. connect via 220ohm resistors like in picture




5. Solder together pin 7 and 8, connect via 220 ohm resisitor pin1 of 23k256 and pin 22 of main uProcessor




6.connect via 220 ohm resisitor pin2 of 23k256 and pin 29 of main uProcessor




7. Use short piece of wire to connect pin 7 and 8 of 23k256 sram to right hole under this little thinny (capacitor)...






Voila,

when powered on, EMUL MUST SAY SRAM OK

[lolafg]

Hi Lotharek ,

would you consider selling a kit for Rev B owners ,if yes i would be interested , i'm a noob in soldering but my brother could do the job for me .

thanks in advance for your answer.

I can't join you in your site has i don't use Outlook...

edit : found your email.

[lotharek]

REV B is no more anymore available

Now, REV C is coming. also kits ill be availabel (PIC+BOARD)

[nurgle]

Sorry for digging up that ancient thread. I just found out that I have a REV B board and think about upgrading it. Are the pictures for this step by step guide available anywhere?

[Jeff]

Sorry for digging up that ancient thread. I just found out that I have a REV B board and think about upgrading it. Are the pictures for this step by step guide available anywhere?

Hello,

This is in the releases notes :

22/08/2010: Firmware SD HxCFloppyEmulator v1.3.0.0

- Amiga Write support added :

Note to the Revision B PCB owners :

To activate this new features you need to add a Microchip 23K256 SPI SRAM chip and 4 resistors.
The connection to do is :

23K256 pin 1 -> 220ohms resistor -> PIC18F4620 pin 22
23K256 pin 5 -> 220ohms resistor -> PIC18F4620 pin 27
23K256 pin 6 -> 220ohms resistor -> PIC18F4620 pin 28
23K256 pin 2 -> 220ohms resistor -> PIC18F4620 pin 29
23K256 pin 8 & 7 -> VCC3.3V (this voltage can be found at the capacitor under the sdcard connector or at the output of the regulator)
23K256 pin 4 -> GND
23K256 pin 3 -> Not connected.

(a 100nF capacitor is also recommended at the pin 8 of the 23K256)

After this modification you should see the message "SRAM OK" at power up.

[nurgle]

Yes I read that in the release notes. It would have been easier with the pictures that seem to have existed in this thread at some point.

If someone else can attach a picture of his modded REV B board that would be appreciated as well.

[nurgle]

Update: Just after posting I found something via google picture search. Hope it is okay to link it: http://www.mfilos.com/2011/01/a600-aca6 ... c-mod.html

That solves it for me. Clear enough to follow.