Who else is building a Beeb from scratch?

[MarcRetro]

This is the status of my last board. And it is still working.

[!FOZ!]

Loving the updates on this thread and pictures!

After getting my board working and then spec’d up early this year - it has since sat in a carry case waiting for me to design a new case for it. I have zero skills in designing such thing so its awaiting time when I can really dig in and enjoy that journey - likely later this year.

My only regret with the build is not selecting black connectors - but other than that very pleased with it. Populating this board and the challenges along the way was a huge undertaking for me and I am so proud of the results - I am happy taking a little break for now.

My vision is to have it in a clear case in my living room with wireless power up, and devices such as keyboard, mouse and joystick - the later options are technically working right now.

Meanwhile I very much enjoy this thread and learning about blue and now red replicate boards!

[!FOZ!]

IMG_7510.JPG

This is the status of my last board. And it is still working.

Love it Marc and the backstory you shared as well. That really looks like the real thing in green as well - v nice job!

[MarcRetro]

My red board does work but many of the connectors don't fit.

[!FOZ!]

My red board does work but many off the connectors don't fit.

Despite that it is a thing to behold in red for sure - and the all black connectors really work well. I love the blue, but honestly I think I would have gone for red if it had been an option to choose. Or purple maybe!

[MarcRetro]

My latest board still has some slight difference from the original. But I will never tell.
There will be a revision 3 and sure I wouldn't doubt about a 4th
I have many ideas for the future
A totally static version without Dram......
All 16 ROMS on the main board.....
WD1770 on the main board....
Or maybe you tell me?

[MarcRetro]

My goal for 50 years is to make a Gold edition......
Did I say it out loud....
Still some years to go.....

[!FOZ!]

My goal for 50 years is to make a Gold edition......
Did I say it out loud....
Still some years to go.....

[!FOZ!]

Or maybe you tell me?

Those all sound excellent - RGB2HDMO onboard? RTC? And maybe native headers and circuit for UPRS - make it slick for developers.

[markusher]

Or maybe you tell me?

Plug in header for the econet ADF10 module like on the Master 128 instead of the econet circuitry. Will still probably need jumpers for the station id.
Internal co-pro header / header to directly attach the pi to the tube.
Internal header for gotek

[MarcRetro]

I made an Econet module for the master last year, including termination on board.
I'm working on a version with clock module on the same board.
But It would be easy to make a BBC C board with an option like this.

[MarcRetro]

Looks like I did not read all, my bad.
A internal connector for floppy drive or gotek is one of the first.
Also an internal tube for sure...

[maniacminer]

I made an Econet module for the master last year, including termination on board.
I'm working on a version with clock module on the same board.
But It would be easy to make a BBC C board with an option like this.

By going to SRAM and putting Econet on a daughter board, you'd save quite a lot of space. Probably do the same for the disc controller that would simplify layout and save even more space. Improve the audio circuitry so it isn't buzzing. Internal Tube with level shifters ready to just take a Pi. Also put SRAM as sideways RAM and Flash as SWROM. A 256 colour MODE2 160x128 would be nice to see

[thedark]

A conector to hdmi and gotec support is nice.
But save it for the master replica. I buy one for sure

[MarcRetro]

Loving the updates on this thread and pictures!

After getting my board working and then spec’d up early this year - it has since sat in a carry case waiting for me to design a new case for it. I have zero skills in designing such thing so its awaiting time when I can really dig in and enjoy that journey - likely later this year.

My only regret with the build is not selecting black connectors - but other than that very pleased with it. Populating this board and the challenges along the way was a huge undertaking for me and I am so proud of the results - I am happy taking a little break for now.

My vision is to have it in a clear case in my living room with wireless power up, and devices such as keyboard, mouse and joystick - the later options are technically working right now.

Meanwhile I very much enjoy this thread and learning about blue and now red replicate boards!

I have been thinking about a case too. I think making a drawing would be possible for me. The tough part is producing it. 3D printing would not be the way I think. Injection mold would be great. I been googling about that. But it will be costly and most producers have minimum quantities in the 100 or 1000 pieces.

[dominicbeesley]

I've been considering a powder coated sheet metal case. Though I'm assuming to make something smaller than a Beeb but slightly bigger than an Electron to take a full size model b keyboard

[MarcRetro]

By going to SRAM and putting Econet on a daughter board, you'd save quite a lot of space. Probably do the same for the disc controller that would simplify layout and save even more space. Improve the audio circuitry so it isn't buzzing. Internal Tube with level shifters ready to just take a Pi. Also put SRAM as sideways RAM and Flash as SWROM. A 256 colour MODE2 160x128 would be nice to see

It would be nice to make some room on the board. I was already thinking about removing the 8271 circuit and replacing it with WD1770 circuits.
Replacing the 16 Drams with one Static ram chip of 128k or 256k would make a lot of space. Also an expansion connector with all the address and data-lines on the board would be great. (Even Steve Furber mentioned it in a interview...)
An other way to make room is skipping the HF and composite from the video circuit. RGB only works fine. And making an internal connector to fit an RGB-HDMI converter board.

[baz4096]

I've been considering a powder coated sheet metal case. Though I'm assuming to make something smaller than a Beeb but slightly bigger than an Electron to take a full size model b keyboard

TNMoC have a folded steel Beeb... I shall endeavour to obtain photos!
Also, I picked up a Fuze RPi case a week or two back which is similar sized to an Elk. Inspiration fodder.

[markusher]

It would be nice to make some room on the board. I was already thinking about removing the 8271 circuit and replacing it with WD1770 circuits.

Although some software is not compatible with the 1770, only the 8271.
I wouldn't like to give up my 8271 been. It's used more often than the one's with 1770.

[MarcRetro]

Although some software is not compatible with the 1770, only the 8271.
I wouldn't like to give up my 8271 been. It's used more often than the one's with 1770.

That is funny how everyone has his own experience. My first Beeb was a Master and I was used to a WD1770 controller. After a few years the Master stopped working when there was a lightning strike nearby. It was send to a repairshop and it would take more than a month to get it fixed. Then I got a secondhand BBC B with a Solidisk 1770 fitted, so I never really tried the 8271. I never ran into problems.

I have some beebs now with a fitted 8271, but I think they will all get an upgrade.
A year ago I made a very small version of the WD1770 upgrade which is hardly larger than the socket.
It works with the standard Acorn DFS and ADFS roms, like the Solidisk v2.

The only problem is that the 1770 chips are getting scarce.

[!FOZ!]

I've been considering a powder coated sheet metal case. Though I'm assuming to make something smaller than a Beeb but slightly bigger than an Electron to take a full size model b keyboard

Yes that’s exactly my thought as well - especially since i am using a smaller PSU. I was thinking of having the main pcb layer and then a layer below with the USB4VC PSU, the wireless keyboard, joystick and mouse adapters etc. Then only HDMI out and power in. With some kind of auto wake feature when the keyboard is hit. All no idea yet how to do this!

[!FOZ!]

I've been considering a powder coated sheet metal case. Though I'm assuming to make something smaller than a Beeb but slightly bigger than an Electron to take a full size model b keyboard

TNMoC have a folded steel Beeb... I shall endeavour to obtain photos!
Also, I picked up a Fuze RPi case a week or two back which is similar sized to an Elk. Inspiration fodder.

The Beeb PCB is roughly size of ATX PC motherboards - see this video - which also is inspiring me though I am going for a smaller look and no need for physical discs - https://youtu.be/R9k7dgKrrnE?si=y5deiMr_BnKrbEfv

[acorn_fan]

Hi, just started out today with my new beeb project. Read this whole thread carefully before starting, so glad to be benefiting from all your experiences. Particularly appreciating the where to find resistors and capacitors download. wish me luck!

[thedark]

Injoy the build. Youl need a donorboard for the parts you cant buy anymore.
Mine is already working only econet has to be done.

[acorn_fan]

I have worked out where all the resistors and capacitors are and created an index for both part number and value.

thanks so much for this! really sped me along. I might have been reading it wrong but there were a few possible differences to my reading of the PCB: C24 is NW IC96 not IC26; C25 missing (and not in BOM) but that seems to cause an issue earlier in this thread; C45 in your list but not the BOM - is it needed?; C46 is NE IC75 not IC46; R159 is N IC7 (missing in list). I'm fairly new to this so please forgive me if I'm missed the obvious

One more general question: how are people going about the "final" PCB clean? I'm using IPA spray between soldering efforts which clears the worst of the flux, but it's still feeling sticky and not as clean as I'd like. Do I need to keep going or try something else?

[Ukwebb]

My latest board still has some slight difference from the original. But I will never tell.
There will be a revision 3 and sure I wouldn't doubt about a 4th
I have many ideas for the future
A totally static version without Dram......
All 16 ROMS on the main board.....
WD1770 on the main board....
Or maybe you tell me?

All of the above with space for video nula rather than stock ula
And prewired sockets for SRAM/EEproms and 32k too

[basdejong]

hi,
Just joined this forum, haven't read much.
Saw your post: I've build a bbc completly from scratch on experiment/wirewrap board (16x10cm) using thin CuL wire, and a smaller board aside for video, audio and keyboard interface. I use a standard PC keyboard, with a AT89C2051 to interface to the bbc.
Will post some photos of someone is interested..

Bas

[Ukwebb]

hi,
Just joined this forum, haven't read much.
Saw your post: I've build a bbc completly from scratch on experiment/wirewrap board (16x10cm) using thin CuL wire, and a smaller board aside for video, audio and keyboard interface. I use a standard PC keyboard, with a AT89C2051 to interface to the bbc.
Will post some photos of someone is interested..

Bas

This sounds very deserving of its own post... And very interesting too

[maniacminer]

I have worked out where all the resistors and capacitors are and created an index for both part number and value.

thanks so much for this! really sped me along. I might have been reading it wrong but there were a few possible differences to my reading of the PCB: C24 is NW IC96 not IC26; C25 missing (and not in BOM) but that seems to cause an issue earlier in this thread; C45 in your list but not the BOM - is it needed?; C46 is NE IC75 not IC46; R159 is N IC7 (missing in list). I'm fairly new to this so please forgive me if I'm missed the obvious

One more general question: how are people going about the "final" PCB clean? I'm using IPA spray between soldering efforts which clears the worst of the flux, but it's still feeling sticky and not as clean as I'd like. Do I need to keep going or try something else?

Thanks for the correction (IC96/IC26) I have updated the PDF's

C25 is a special capacitor, it should be silver mica or polyester film as it provides the integration slope for the analogue->digital conversion. But if you're not too bothered by it then by all means stick anything in that is the right value, NP0 ceramic, or, failing that an X7R ceramic.

R159 should be in the list!?! It's the feedback to the LM324 for the transistor pair that conditions the audio going into the the serial processor.

C45 is a capacitor that may or may not be fitted depending on the performance of the colour burst timing for the composite video/UHF circuitry, the associated R109 is a select on test value - I have no idea how/why this is selected...

As for cleaning, I do it all in one go, first a bulk clean with cotton wool balls soaked in IPA, then I do it again a second time and third time a spray over with Fluxclene and there is no residue whatsoever. I'd leave it until the end otherwise you'll waste a lot of time and resources for nothing more than vanity...

[maniacminer]

hi,
Just joined this forum, haven't read much.
Saw your post: I've build a bbc completly from scratch on experiment/wirewrap board (16x10cm) using thin CuL wire, and a smaller board aside for video, audio and keyboard interface. I use a standard PC keyboard, with a AT89C2051 to interface to the bbc.
Will post some photos of someone is interested..

Bas

Sounds fun, it's a lot easier using CuL (lacquered copper wire) as point to point wiring can be easily stacked vs. traditional dual/quad layer PCBs. You should start a new thread in the Acorn 8 bit hardware and give plenty of photos