Built up a 16MHz board last night but unfortunately did not have time to test as it was the small hours of the morning.
I expect exxos will be testing his today way before me - challenge laid down
After the mess-o-wires to patch the ALPHA board to True 16MHz Mode I am looking to put this one in with a bit more elegance (he says remembering how rubbish his soldering is
)
My plan is to replace all the resistors of the CLK lines of the ALPHA board with headers so that I can plug in from this 16MHz board to the various points. Will also look at hot snot gluing the 16MHz board where the ALPHA Remake text is on the top of the board once working.
If you look at the image of my ALPHA running at 16MHz, you can see I am tapping into the CLK line resistors. E.g. the orange boxes of the CLK lines to the MFP 68901 and the other to the DMA (or in my case the NOT SO NASTY DMA
). Those resistors will be removed and headers put in their place so I can tap the 16MHz board in easily with some jumper wires. Also give me an excuse to label the wires.
- IMG_3797.jpg (158.34 KiB) Viewed 6620 times
Note: Below is a pic of my 16MHz board and the provisional components I have used. These are
untested as of yet and there are some track cuts to do as well on the ALPHA board. Once we have these 16MHz boards working we will post full instructions.
- 2 x 1uF 0805 (one of these is soldered on the underside of the board - I left this one as the last component to put on by hand
- 5x 33R 0805 - Have currently gone with 33R as that is the value of the original resistors on the CLK lines. These could change.
- 1x SN74LVC1G08DCKR
- 1x MC74ACT161DG
- 1x OSC - 32.084988MHz
- IMG_3965.jpg (171.47 KiB) Viewed 6620 times