The rise of FreHD

[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.

[Tomswork]

Nice project are you going with led on board or with pin headers


Tom
@rubber_jonnie

[rubber_jonnie]

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.

[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...

[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.

[Tomswork]

More parts day is always fun

Tom

@rubber_jonnie

[rubber_jonnie]

More parts day is always fun

Tom

@rubber_jonnie

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

[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.

[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...

[Tomswork]

Looks good

Tom