Page 1 of 9

The rise of FreHD

Posted: 04 May 2023 14:25
by rubber_jonnie
Thought I'd document the build of my FreHD here for all to see!!

So far, I've been lucky enough to find nearly all of the components in my parts drawers.

In fact I'd say I have probably 90% of what I need, so I can get on with the build while stuff I don't have, such as the PIC and a couple of the ICs are ordered.

Everything is here waiting in the project box, though nothing is soldered yet :)

PXL_20230504_131347618.jpg

I can't imagine it'll take long to build and I'm very much looking forward to having some decent storage available for the TRS-80.

I need to look at the M1 interface remake next, which should be simple as it'a literally 2 transistors and 2 resistors on a PCB linking the machines 40 pin expansion socket to the 50 pin socket of the drive.

Re: The rise of FreHD

Posted: 04 May 2023 15:30
by Tomswork
Nice project are you going with led on board or with pin headers


Tom
@rubber_jonnie

Re: The rise of FreHD

Posted: 04 May 2023 16:47
by rubber_jonnie
Tomswork wrote: 04 May 2023 15:30 Nice project are you going with led on board or with pin headers


Tom
@rubber_jonnie
TBH it's probably going to be on board LEDs.

Re: The rise of FreHD

Posted: 05 May 2023 14:16
by rubber_jonnie
Well, FreHD is a very easy build compared to the v2Analog boards, but at least I learned some new skills with all the recent micro soldering I've done :)

Just waiting on a few components to complete the build:

PXL_20230505_130859911.jpg

Need to start work on the M1 adapter really...

Re: The rise of FreHD

Posted: 09 May 2023 13:45
by rubber_jonnie
More parts arrived today:

PXL_20230509_115627719.jpg

So all that's left, aside from more assembly, is the battery holder and 2 74 series logic IC's.

I'd better start looking at getting the PIC programmed (The GAL is done already) and the M1 interface, plus the patched ROM to allow autobooting on the Model 1.

Re: The rise of FreHD

Posted: 09 May 2023 22:04
by Tomswork
More parts day is always fun

Tom

@rubber_jonnie

Re: The rise of FreHD

Posted: 09 May 2023 23:52
by rubber_jonnie
Tomswork wrote: 09 May 2023 22:04 More parts day is always fun

Tom

@rubber_jonnie
Indeed it is, hopefully tomorrow will bring the final bits :)

Re: The rise of FreHD

Posted: 10 May 2023 23:52
by rubber_jonnie
Argh!!

So in the office today, and get home to find just the one of 3 outstanding parts arrived in the post today :(

Fingers crossed for tomorrow, just need to get the PIC programmed now, which my TL866 Pro will do.

Re: The rise of FreHD

Posted: 11 May 2023 10:57
by rubber_jonnie
And the last IC arrived this morning :)

So aside from the battery holder, which isn't required for it to work, it's complete.

PXL_20230511_093936716.jpg

PIC and GAL are done, but I did find one 'gotcha' for anybody building these.

The power plug has GND on the left pin and 5v on the right pin. I fitted a standard 4 pin micro molex connector, but later realised when connected it would reverse the connection, which is not good.

It was a simple task to pull the white plastic component off and flip it over and resolve the issue, but anyone building this needs to be aware of it.

I found a spare 50 pin cable, so next I need to sort out the M1 adapter, which I keep putting off...

Re: The rise of FreHD

Posted: 11 May 2023 21:11
by Tomswork
Looks good

Tom