kodak80 H4 build (x2)

[Icky]

@kodak80 , I think @exxos may be right but could be the angle of the pic. I had a very small hairline solder bridge short on my SN74LVC1G11DBVR on the bottom right

[kodak80]

It looks okay to me.

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[Icky]

It looks okay to me.

Must of been the angle of the other pic

[kodak80]

Okay, first board is built apart from external connectors. Have a Falcon 4mb RAM board to fit and also a 4mb SIMM so I can test both options (not at the same time though).

Still need to run through the fixes as well.

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[exxos]

Looking good

[kodak80]

After taking the photos I found that the 74LS02 IC had a bent pin not in the socket so this is now fixed.

I have socketed the 32mhz OSC for now using 4 individual female pins which allows me the flexibility of using a cheap 32.0mhz OSC for initial testing and can change over to the proper OSC once I know the system boots. With this setup, the OSC just misses the PSU metal plate so will need to cover the OSC when powered on. Would it cause issues if the OSC metal case touches the PSU metal plate and is grounded?

I am thinking that I will stick with the 13 pin din video port. @exxos and @Icky Any benefits on using the VGA port instead? I guess it will be hard to swap these once one is soldered in.

[kodak80]

https://www.exxosforum.co.uk/forum/posti ... 78&p=29092
@exxos and @Icky Just wondering the best option for the BGACK PULLUP fix if the expansion port sockets are not installed?

Edit: here is the fix applied to the PLCC CPU socket along with the DTACK fix.

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[kodak80]

Okay, fitted the 13 pin din video connector (not yet soldered in but fairly sure the pins are all connected to the board) along with the Falcon 4mb RAM card and powered on......

White screen, same as @derkom. I have a known working Exxos 1.02/1.04 TOS ROM from one of my Alpha boards in place so it is not this that is the issue.

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Blitter jumpers are connected as I do not have a blitter in the socket yet. All jumpers as per @Icky guide.

No floppy access attempt. Do not have one connected at the moment though.

Also tried with a 4mb SIMM instead of the Falcon RAM card but the boot up was the same white screen.

At least there was no magic smoke so not unhappy with where I am at the moment and may have to wait for more skilled builders to get to booting their boards.

[PhilC]

Well done for getting this far so quickly.

Sounds like itll be an easy fix once someone finds it.

[kodak80]

Thanks @PhilC I did seem to power through this one compared to the Alpha board.

Still scary turning on the power though.