Beeb 1MHz Bus FPGA Adaptor

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roland
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by roland » Tue Apr 02, 2019 9:37 pm

hoglet wrote:
Tue Apr 02, 2019 8:26 pm
For Atom 2018, are you planning to order a batch of 10 of the FPGA boards? Or does everyone buy there own?
I will consider to order these in a batch of ten, maybe it could lower the price. But I am a bit worried about import taxes..... those might increase the total costs.
FPGAtom: much better than Atom2k15 which was even better than the real thing.
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tricky
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by tricky » Tue Apr 02, 2019 9:48 pm

Have you looked at the news/SNES for your expansion ideas?

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roland
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by roland » Wed Apr 03, 2019 6:06 am

I'm just worried that people will order the the wrong version of the board, if everyone has to ask for a "special"
If you haven’t ordered your new boards then I can ask Eepizza if he can list a board without headers or make it an option at the current listing.
FPGAtom: much better than Atom2k15 which was even better than the real thing.
MAN WOMAN :shock:

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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Wed Apr 03, 2019 6:54 am

roland wrote:
Wed Apr 03, 2019 6:06 am
If you haven’t ordered your new boards then I can ask Eepizza if he can list a board without headers or make it an option at the current listing.
That would be good for him to do anyway I think, to avoid confusion. And if he could update the photo to match the actual item that would be brilliant.

I think it''s best to try to support both forms of the board. I known several people (me included) already have this board.

I can think of a couple of solutions:
1. With the current adaptor design, just solder the FPGA sockets (and buttons and LEDs) to the reverse side, and then use it upside down.
2. Provide two positions for the additional 6x2 and 1x2 sockets, route both, and provide some jumpers for the 3.3v connections
3. Produce two versions of the FPGA adapter board

I think (2) and (3) would need different .ucf files.

Let me think about this some more.

Dave
Last edited by hoglet on Wed Apr 03, 2019 6:54 am, edited 1 time in total.

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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Wed May 01, 2019 6:06 pm

Hi all,

I've just built up version 2 of the Beeb 1MHz Bus FPGA Adaper and everything seems to be working correctly.
IMG_1656.JPG
IMG_1657.JPG
I used longer pads for the 0.8mm pitch TSOP-II SRAM, and it was pretty easy to solder.
IMG_1659.JPG
This is the only surface mount device, everything else is through-hole. It's also optional, depending on what you actually want to build. The Music 5000, for example, does not need this. But the MandelBrot renderer does. The FPGA has 64KB of internal block RAM, which is sufficient for many applications.

I'm now ready to make bare PCBs available to people. I'm not currently planning to sell kits or fully built boards. This is definitely a DIY project. Unless, of course, people bribe me with large amounts of money :lol:

Over the next couple of days I will create some Wiki pages with PDF schematics, Bill Of Materials, etc.

Edit: Orders moved to first post

Dave
Last edited by hoglet on Wed May 15, 2019 10:34 am, edited 20 times in total.

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KenLowe
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by KenLowe » Wed May 01, 2019 6:16 pm

Please count me in. I can't resist these projects!

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Elminster
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by Elminster » Wed May 01, 2019 11:01 pm

I am interested in a board if any left, if not I wait for the next batch, assuming there is one.

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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Thu May 02, 2019 5:11 am

KenLowe wrote:
Wed May 01, 2019 6:16 pm
Please count me in. I can't resist these projects!
Added to the list.
Elminster wrote:
Wed May 01, 2019 11:01 pm
I am interested in a board if any left, if not I wait for the next batch, assuming there is one.
Added to the list, but Roland just beat you to the last board from the first batch.

I'll also order a second batch of boards tomorrow.

Dave
Last edited by hoglet on Thu May 02, 2019 5:21 am, edited 1 time in total.

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by paulv » Thu May 02, 2019 6:13 am

If you could add my name to the list for a board I'd appreciate it.

Thanks

Paul

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by jasonl » Thu May 02, 2019 8:26 am

Please could you add me to the list, too. It'll be fun comparing the M5000 emulation with real hardware. :)
Thanks!

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by marcusjambler » Fri May 03, 2019 3:59 pm

Board arrived safe n sound.

Thanks Dave

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by fordp » Fri May 03, 2019 4:11 pm

I will take a board please.
FordP (Simon Ellwood)
Time is an illusion. Lunchtime, doubly so!

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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Fri May 03, 2019 4:18 pm

fordp wrote:
Fri May 03, 2019 4:11 pm
I will take a board please.
You need to check your PMs!!!!

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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Fri May 03, 2019 5:21 pm

All the boards from from the first batch of ten have now been posted out.

I've ordered a second batch of ten today and I expect to have those in 2-3 weeks.

I've also created a BOM on the Wiki, with Farnell links for all the required parts:
https://github.com/hoglet67/Beeb1MHzBus ... -Materials

The BOM also includes links to the FPGA Board and the FPGA Programming cable. Both will take some time to come, so if you are waiting for a board from the second batch, then now would be a good time to order. If it comes early, you can always do a simple VHDL project on the FPGA board to make some "knight-rider" blinky lights. I might actually do that myself, as it would be a good initial test for programming the board.

I'll try to add some assembly notes at some point over the weekend, but it's all pretty straight forward.

Dave

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Sun May 05, 2019 12:49 pm

I've added some some Assembly Notes to the wiki:
https://github.com/hoglet67/Beeb1MHzBus ... mbly-Notes

These cover:
- Assembling the Beeb 1MHz Bus FPGA Adaptor
- Initial testing
- Testing with Music 5000 on the Beeb/Master
- Testing with DSP Fractal Renderer on the Beeb/Master

Please let me know if any steps require further explanation. It's very easy to just make assumptions when writing documentation like this.

Dave

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Sun May 05, 2019 1:47 pm

I've added an additional optional item to the BOM. A PModVGA adapter, for anyone that wants to play with generating VGA video:
https://github.com/hoglet67/Beeb1MHzBus ... ccessories

The [DSP Fractal Renderer](https://github.com/hoglet67/DSPFract) design needs this.

Dave

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Mon May 06, 2019 4:34 pm

Hi all,

There are, in fact, other uses for the Beeb 1MHz Bus FPGA Adaptor that don't actually involve Beebs, or 1MHz Buses.

It turns out it's a pretty reasonable platform for running Atom FPGA:
IMG_1661.JPG
IMG_1662.JPG
IMG_1664.JPG
IMG_1665.JPG
It's at least as good as most of the other platforms, and is better in certain respects because of the decent quality SPI DAC. Atom SID never sounded so good!

Now, I'm wondering what I could actually do if I did properly interface this to the Beeb's 1MHz Bus. It could provide a great debugging interface for the Atom. Food for thought.....

Dave
Last edited by hoglet on Mon May 06, 2019 4:42 pm, edited 1 time in total.

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by Kazzie » Mon May 06, 2019 6:53 pm

hoglet wrote:
Mon May 06, 2019 4:34 pm
Hi all,

There are, in fact, other uses for the Beeb 1MHz Bus FPGA Adaptor that don't actually involve Beebs, or 1MHz Buses.

It turns out it's a pretty reasonable platform for running Atom FPGA:

IMG_1665.JPG
"20th Century Text"! It's years since I last saw that. :)

Sadly it seems that it's also years since the last progress update on it...
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Mon May 06, 2019 7:04 pm

Kazzie wrote:
Mon May 06, 2019 6:53 pm
"20th Century Text"! It's years since I last saw that. :)

Sadly it seems that it's also years since the last progress update on it...
There a few more screen shots in the original thread:
viewtopic.php?f=44&t=9304

It was a great demo of the new 80x40 character/attribute mode screen.

Dave
Last edited by hoglet on Mon May 06, 2019 7:04 pm, edited 1 time in total.

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by Kazzie » Mon May 06, 2019 7:17 pm

hoglet wrote:
Mon May 06, 2019 7:04 pm
Kazzie wrote:
Mon May 06, 2019 6:53 pm
"20th Century Text"! It's years since I last saw that. :)

Sadly it seems that it's also years since the last progress update on it...
There a few more screen shots in the original thread:
viewtopic.php?f=44&t=9304

It was a great demo of the new 80x40 character/attribute mode screen.

Dave
Thanks for the link. It looks a lot better in green-on-black text than the original Java app did. :)
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
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roland
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by roland » Sun May 12, 2019 12:03 pm

Hi Dave,

Just checking your BOM:

IS61WV5128BLL-10TLI
512Kx8 10ns SRAM Farnell 2901200

Is this the correct SRAM? It looks like the TSOP-II to me.
FPGAtom: much better than Atom2k15 which was even better than the real thing.
MAN WOMAN :shock:

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roland
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by roland » Sun May 12, 2019 12:37 pm

Just an idea: I ordered a few of these: https://nl.aliexpress.com/item/10-stks- ... 21960.html and I want these to use for the FPGA board. So I can swap one FPGA module either way around between this FPGA adaptor and my FPGAtom as long as I use male headers on the adoptor (on my Atom there are already female strips).
FPGAtom: much better than Atom2k15 which was even better than the real thing.
MAN WOMAN :shock:

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by Elminster » Sun May 12, 2019 12:44 pm

That would be good. I was wondering whether to order one or two FPGAs, only ordered one, so be good to multi use. Already have one in the ICE-T. Beginning to think they might be like Rasoberry pis, where I have 15 PIs but always need one more.

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Sun May 12, 2019 1:06 pm

roland wrote:
Sun May 12, 2019 12:03 pm
IS61WV5128BLL-10TLI
512Kx8 10ns SRAM Farnell 2901200

Is this the correct SRAM? It looks like the TSOP-II to me.
It is TSOP-II.

Here's it soldered onto my board:
IMG_1659.JPG
What package did you think I used?
Last edited by hoglet on Sun May 12, 2019 1:08 pm, edited 1 time in total.

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roland
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by roland » Sun May 12, 2019 2:55 pm

I was mixing up the SOJ32 on Farnell website. I am not used yet to the non-dil packages. So I double checked to make sure.
FPGAtom: much better than Atom2k15 which was even better than the real thing.
MAN WOMAN :shock:

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Wed May 15, 2019 4:32 pm

Hi all,

Just to say, everyone's boards have now been posted.

I've moved the order status list to he first post of this thread:
viewtopic.php?p=229924#p229924

I have 7 boards left from batch 2 if anyone is interested. Details in the first post.

There are currently three projects that use this board:
- Music 5000 + 3000
- DSP Mandelbrot renderer
- Atom Fpga

Documentation is on the github wiki:
https://github.com/hoglet67/Beeb1MHzBusFpga/wiki

Hopefully as people start experimenting there will be more projects to try out.

Dave
Last edited by hoglet on Wed May 15, 2019 4:33 pm, edited 1 time in total.

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by dominicbeesley » Wed May 15, 2019 6:58 pm

Thanks Dave,

I've just spent the past few hours soldering mine up and testing it out and its gone pretty straightforwardly.
20190515_191720-s.jpg
I have some observations - none are showstoppers or even whinges but you may want to consider them for any future mk3 board?

- a warning that the bottom and top fill planes are not both GND - that had me chasing my tail for a few minutes? Maybe something on the solder mask to remind people like me who don't RTFM!
- a jumper to connect the audio DAC outputs to the 1MHZ bus audio? (a couple of resistors to mix down and a cap)
- R5, R6 are a bit on the low side for modern retina scorching LEDs (I used two from my random pile) one is comfortable with 1.5K, the other a 3mm white jobbie needs 10K avoid the need for a factor 50 and a welding mask!
- bleed resistors on the audio outputs?
- A warning that the FPGA and regulators seem to get very (burnt my finger) hot when running the DSPFract demo - I guess its working pretty hard!
- caps on opposite side of board to SRAM - this was a little fiddly, consider moving?

Once again, none of the above are criticisms, just first impressions when building. Thanks again for another excellent useful project! =D>

D

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hoglet
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Re: Beeb 1MHz Bus FPGA Adaptor

Post by hoglet » Wed May 15, 2019 7:10 pm

Thanks for the feedback Dominic. All noted.

I must say I haven't noticed the FPGA/regulators getting hot. I'll check mine do that same tomorrow. It doesn't surprise me, as DSP Mandelbrot uses every single one of the multipliers, and runs them at ~240MHz. If things are getting too hot, I will dial this back a bit....

Oh, if you build the latest version of the DSP Mandelbrot from source, there's a nice little extra feature if you press SW1 as the Beeb is being powered up....

Dave
Last edited by hoglet on Wed May 15, 2019 7:11 pm, edited 2 times in total.

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by roland » Wed May 15, 2019 7:38 pm

hoglet wrote:
Wed May 15, 2019 4:32 pm
Hopefully as people start experimenting there will be more projects to try out.
If somebody has no inspiration: viewtopic.php?f=44&t=17108&p=236924 :mrgreen:

I got my components yesterday except for the FPGA module. That's on its way now....
FPGAtom: much better than Atom2k15 which was even better than the real thing.
MAN WOMAN :shock:

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Re: Beeb 1MHz Bus FPGA Adaptor

Post by dominicbeesley » Wed May 15, 2019 8:11 pm

Cool Dave, I pondered over the "auto boot" for hours when I was porting the 6809 MOS (I think JGH solved the mystery for me) and wondered if anything ever used it...better late than never.

I wondered what all that stuff was in the vhdl which I only looked at cursorily....I needed to fit the IRQ jumper to find out!

Roland, the idea of an fpa for the beeb has been on my list of thought experiments for a while...quite a bit of work but might be fun.

D

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