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464 Resurrection - with only mainboard!

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WacKEDmaN:
hooked up scart..and powered up the board..


..and nothing.. seems to draw about 0.9Amp and there seems to be activity on the z80 buses.. (checked with oscilloscope..)
...need to checked voltages ..seems to be 4.3v on everything..

CRTC chip (HD6845SP)seems to be getting warm after a few minuites.. (ram very slightly).. is it known to get warm to hot? (its not burning hot!)


seems to be working..i just cant get a picture  ::)
..i might invest in a cga/ega to vga board...the scart to RF modulator is horrible, i plugged wii into it to make sure it works..
..ok thats ordered.. should be here by the end of the year if im lucky!  :)


WacKEDmaN:
so the EGA/CGA to VGA board arrived today...
wired it up (soldered to the pins on bottom of cpc board)... this board and pinout.. https://www.octoate.de/articles/connect-cpc-to-vga-display/


but still no picture...

Question: does the cpc "need" anything else connected on boot? like does it look for the tape drive or keyboard? im guessing not
i cant test the the board is working (just no pic) with no speaker or keyboard! (cant hit esc/delete to beep!)... i suppose i could hook up an amp and speaker to the headphone jack.. but bit hard to make a keyboard from an arduino without the display showing!

next step is to replace the Z80... i tryed it on a bread board and it was doing weird things on the bus.. (would stop increasing the address bus after a few cycles just doing nops..should continue increasing right?)
be a few more weeks before ill get my hands on them tho with xmas and new years 

Bryce:
The CPC Mainboard will run with nothing attached accept the power cord. You would need some test equipment to know whether it's running or not, so it easier to have it connected to a display at least.

Bryce.

WacKEDmaN:
thanks Bryce
i do have an oscilloscope.. (guess i need a logic analyser)..
not sure what i should be looking at!.. i am seeing activity on both the data and address buses on all the main chips..and the logic chips seem to be all be working...


but like i said i think the z80 maybe bad..so im going to replace that first..
...another month before i get to move on!..unless someone has some ideas for me! :P

Bryce:
What are you getting on pins 39 and 40 of the CRTC?

Bryce.

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