YARRB [SOLD OUT]

[IanS]

Today I noticed that the 29F010 and 39SF010 are not pin compatible. It turns out that the Yarrb board is designed only for 39FS010. So do not use a 29F010 or 29C010 in this board!

Which pins are different, they look the same to me.

[IanS]

I think you are comparing TSOP and DIP packages. Compare like for like.

[roland]

You're absolutely right. I was mislead by the drawing of the pinout in the datasheet. I removed my posts to avoid any confusions.


PS: you might also delete yours so that this mistake was never made

[IanS]

PS: you might also delete yours so that this mistake was never made

As a non-admin I don't think I can delete my posts. Nor would I want to.

[roland]

If anyone is building these or is considering it then I am still interested in a built one

Are you still interested? I have now three request and I think that's enough for making a new small batch. Any body else wanting a Yarrb board? A board will cost about €15.00. I will have a look how many suitable CPLD's I have left.

Please reply to this post to subscribe for a Yarrb board.

[marcusjambler]

Hi Roland

Yes... still interested

[-B-]

Yes I’m interested, as per our email exchange.

Neil.

[Lardo Boffin]

Although I don’t know whether my Atom works yet I am potentially very interested! Just a couple of questions - mostly so I don’t have to try and understand the whole thread:-
Are they easy to fit (for a hardware noob)? I don’t want to risk damaging my Atom.
Are you selling them complete and ready to use?

Many thanks!

[roland]

Yes, the Yarrb board is easy to use. Most of the work is removing IC's and additionally two wires must be soldered to the CPU socket. Details are at http://diy.acornatom.nl/yarrb.html:

For installing the board you first have to make a few small modifications to the Atom. If you work carefully you can revert these changes with very little effort.

• Remove all the 2114 at the left side of the 6502.
• Remove IC5 (74LS30) and IC6 (74LS138)
• Remove the Atom roms (IC20, IC21 and IC24)
• Remove the 6502 and place it on your ram/rom board
• Solder a wire from pin 36 of the 6502 socket to pin 8 of the IC5 socket (this is the new buffer enable signal)
• Bend out pin 10 of IC44 (74LS393)
• Solder a wire from pin 13 of IC44 to pin 37 of the 6502 socket

So modifications are not destructive for your Atom. It's easy to undo the changes.

I can sell them complete and ready to use. So the EEPROM and CPLD are programmed and the board is tested in my Atom if you want it. Maybe for a little fee so that I can finance my new Atom project

When I have to build a few boards I must not wait too long as the memory chips are almost sold out. There will be Chinese ones but I prefer Farnell (or a similar company) as supplier.

[Lardo Boffin]

Doesn’t sound too bad.

How much for one that is built and ready to use please?

[roland]

At the moment there are three subscribers so I will order five Yarrb boards and the needed parts and sell them either as a kit or assembled and ready to use. If a kit is ordered the EEPROM and CPLD will be programmed.

I don't know the price of the parts yet but I will post them as soon as I know these prices. Assembling will cost £15.00.

[Lardo Boffin]

One for me ready to use please.

[roland]

I have ordered five boards and the needed parts; I expect to receive them by the end of May. So soldering and shipping will be at the beginning of June. Please be patient

[anightin]

Please can you put me down for one of these.

I can do self assembly if it requires standard soldering techniques but would need help if any SMT stuff -- one day I will attempt SMT

Many thanks

Best wishes

Andy

[roland]

This board has no SMT stuff. The CPLD goes into a socket. This board is easy to assemble. I'll put you down on the list for a board.

[anightin]

Much appreciated

[roland]

Today I received my Yarrb boards. As some parts are hard(er) to get I want to sell them as complete kits but I don’t have all the parts yet.

If someone wants a bare board, just drop me a pm or respond to this post.

[roland]

One of the latest serie boards has already been send and three are ready for shipping. So there is one kit left for anybody interested.

Just a small reminder for switching between the profiles can be found here: viewtopic.php?f=44&t=11373&p=144714#p144714

[-B-]

YARRB kit was in my post box when I got home tonight.
Now built and installed and trying to work out how to use it.

Neil.

[-B-]

This board is excellent!

Many thanks Roland.

Now, the 12k games that would not run before, are all working. Could I have had a dodgy text RAM chip?

Neil.

[roland]

Yes, it's possible that one of your 2114's is faulty. You could check them by placing them in the video RAM and then enter CLEAR4. If there are white pixels (except in the upper left corner) or lines then you have probably found it.
I notice you still have the zero page ram in your Atom (IC51 and 52). You can remove these as well.

[-B-]

I notice you still have the zero page ram in your Atom (IC51 and 52). You can remove these as well.

I wasn't sure about those, but when your instructions said "All 2114 at the left side of the 6502" I should have tried it.
My worry is that I break something but the Atom is proving to be almost indestructible.

Been an Atom owner for 1 month now, still learning.

Neil.

[roland]

When the pcb is in good condition we can always repair the Atom. So just experiment as you like

[anightin]

I understand that the EEPROM and CPLD will be pre-programmed in my kit.

My ATOM has the System ROM, A floating point extension ROM and the AtoMMC ROM

Will these already be resident in the EEPROM?

Just checking... what I have to do instead if not?

Build is progressing

Kind Regards

Andy

[hoglet]

My ATOM has the System ROM, A floating point extension ROM and the AtoMMC ROM

Will these already be resident in the EEPROM?

The EEPROM on YARRB replaces all the ROMs on the main board, so they should all be present.

(The existing ROMs can be removed and kept safely somewhere)

[anightin]

Thanks for confirming Hoglet, useful to know.

Glad I keep all my retro computers in boxes, the ATOM box 'safe place' will now get a fresh pad of conductive foam for the job.

[IanB]

One of the latest serie boards has already been send and three are ready for shipping. So there is one kit left for anybody interested.

Hi Roland, is that last kit still available?

[roland]

Yes, I still have one kit available.

[IanB]

Yes, I still have one kit available.

I'd like to buy that one if that's OK, I just sent you a PM.

[roland]

That's OK.

If other people want a Yarrb board then please don't hesitate to ask. There are Chinese sources for the components that are officially end of life. A good second hand CPLD is better than no CPLD