exxos's H5 C1 build

[Steve]

I knew something must have been screwy with my board since the beginning, I've never had any luck with it. Really glad you are looking into it thx

[Icky]

Odd as I have never had issues with the 3V3 bus or regulator. I know there are 7x 5V <-> 3V3 translator chips across the 3V3 already.

Duff chip may be? Not anywhere near my H5's to check.

[exxos]

Odd as I have never had issues with the 3V3 bus or regulator. I know there are 7x 5V <-> 3V3 translator chips across the 3V3 already.

Duff chip may be? Not anywhere near my H5's to check.

It's not duff... Under a 1k load it outputs the correct 3.3v.

[Icky]

Odd as I have never had issues with the 3V3 bus or regulator. I know there are 7x 5V <-> 3V3 translator chips across the 3V3 already.

Duff chip may be? Not anywhere near my H5's to check.

Its not duff... Under a 1k load it outputs the correct 3.3v.

[exxos]

Finally got around to ordering the 220K 0805 resistors to fix the 3.3V bus properly.

I just blobbed normal solder on top of them to remove them all. Clean the pads up with some desoldering braid. Added a tiny bit of SMT paste and heated the suckers up. Done!

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[exxos]

Bit of TOS hackery waffle https://www.exxosforum.co.uk/forum/viewt ... =50&t=5442

This is sooooo cool after a TOS hack I can now use 720K & 1.44 without the HD floppy wire

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Will see if I can emulate the DIP switches in hardware with something at some point. Still not getting the HD format option in GEM

[Steve]

Hey Chris I just noticed on my A3 board the resistors seem to be 100k I think? 1003? Is that suitable or should I swap them?

Cheers

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[exxos]

Hey Chris I just noticed on my A3 board the resistors seem to be 100k I think? 1003? Is that suitable or should I swap them?

100K does seem to be ok in general. But I would recommend changing them to 220K just to be on the safe side.

[exxos]

While testing out the second C1 build, I noticed the audio was distorted in games despite sounding fine in the diagnostic cartridge.

First glance there seems to be a lot of ringing on the audio signal. So just trying to work out why.

[exxos]

Does anyone have a H5 C1 built up and not done the audio mods yet ?

It is really bizarre as the audio test cartridge plays each channel just fine. And yet when I load something like hassle master which plays music it is really distorted and hissy. Similar when I load again with chip music, it is like some voices are fine and then another one is distorted.