Yarrb - redesigned

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chrisn
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Re: Yarrb - redesigned

Post by chrisn » Thu Dec 19, 2019 8:55 am

I have just bought an Atom, as a Christmas present to myself. Hopefully it will arrive soon. So I would also like to register my interest in one of your boards.

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roland
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Re: Yarrb - redesigned

Post by roland » Thu Dec 19, 2019 9:12 am

I have send you a PM with price options. If all of you will buy a Yarrb2 then I have run out of boards of the first batch 8)
I am happy to order a new batch of 5 or 10 boards is there is more interest for it.

Pricing:

1. The basic board: € 40,00
This contains the board with all the SMD components mounted (resistors, capacitors, leds, RAM and CPLD) plus the EEPROM and voltage regulator. Both the CPLD and EEPROM are already programmed.

2. Option - additional sockets and headers: + € 5,00
This contains one 40p socket with turned pins for the 6502 CPU, 2 "needle" strips for fitting the board into the CPU socket on your Atom mainboard and one PLCC32 socket for the EEPROM.

3. Option - completely build and tested board:+ € 20,00
This includes also the second option otherwise I cannot not test it :)

Shipping costs to the UK are € 15,50; this is including track and trace and insurance against damage and loss. This price is valid until December 31 as PostNL will increase postage on Januari 1.

At the moment I only have enough components for six complete kits.

If you order a boards:
1. Inform me by replying with a PM or send an email to roland#acornatom.nl (replace the # with the well known @ !)
2. Pay the money to my Paypal account roland@acornatom.nl using the Friends and Family
3. Let me know if the CPLD should be programmed with the AtoMMC enabled on reset or not

Thanks again for supporting my projects,
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KenLowe
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Re: Yarrb - redesigned

Post by KenLowe » Thu Dec 19, 2019 9:42 am

PM sent. Hopefully quickly enough to get one from your first batch!

Thank you.

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roland
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Re: Yarrb - redesigned

Post by roland » Thu Dec 19, 2019 9:49 am

The members who "pre-ordered" and received my PM yesterday will have one of the first batch :)
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1024MAK
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Re: Yarrb - redesigned

Post by 1024MAK » Thu Dec 19, 2019 1:47 pm

HI Roland

I presume the option regarding the AtoMMC is similar to the earlier YARRB.

From the other thread:
roland wrote:
Sat Jun 25, 2016 10:57 pm
Besides the cpu clock speed it also offers a control signal for the Atom bus buffers. In de power-on default I want to select AtoMMC rom at #Exxx but when the second ROM-bank (with AtomDOS at #Exxx) is selected, the board should disable memory at #0Axx and enable the Atom bus for accessing the 8271 FDC controller of the disc controller board.
Or do you mean something different (and that I have missed)?

Mark

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Re: Yarrb - redesigned

Post by roland » Thu Dec 19, 2019 2:19 pm

It's indeed the same. This Yarrb2 board uses basically the same VHDL code as the previous boards; except there is an additional register for eight LED's. Those LED's might be useful when the board is used as a stand alone system.

More information is at viewtopic.php?f=44&t=11373&start=150#p238312
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Yarrb and AtoMMC

Post by roland » Sat Dec 21, 2019 9:17 pm

For some people the relationship between the Yarrb board and the AtoMMC is not quite clear. So I will try to explain it here for you.

AtoMMC
The AtoMMC is a wonderful mass storage solution for the Acorn Atom. You can use a MMC card to store your files in a directory structure like you are used to on a DOS/Windows PC, an Apple computer or a Unix/Linux system. No hassling with disk images so it is really simple to use. The AtoMMC needs a ROM at either #Axxx (ic socket 24 on the Atom's main board) or at #Exxx on either ROM/RAM expansion board.
If you use the ROM in ic socket 24 then you need to close LK3 and enable the interrupt for the AtoMMC board. On a reset (break) of the Atom, an interrupt will be generated and the Atom kernel will initialize the AtoMMC system automatically.
If you use a ROM at #Exxx then you need a modified Atom kernel which will call the AtoMMC initialization with a JSR #E000 from the Atom's reset routine. This will work without an interrupt. In fact, you are encouraged to disable the AtoMMC interrupt to avoid a hanging Atom if no ROM is present at #Axxx.
The AtoMMC can work without a Yarrb board.


Yarrb board
The Yarrb (Yet Another RAM/ROM Board) is a modern memory extension which gives you 128k RAM and 128k ROM in your Atom. It has three main memory profiles: default Atom, BBC Basic and Atom2k15. More information about the memory map and the configuration bytes #BFFE and #BFFF is in the attached files. The Yarrb2 board has also a register at #BFFD which controls the eight leds on the board.
The Yarrb board does not require an AtoMMC to work.



AtoMMC and Yarrb
As you learned in the above text both Yarrb and AtoMMC can work independent from each other. But the combination of Yarrb and atoMMC gives you a powerful Atom as you have all the memory that you need for using the MMC, the software archive and most (modern) games. The classic games will mostly need 6k of Ram and the modern games need almost all about 32k of Ram.

The default configuration of the Yarrb board is a default Atom with the DOS ROM at #Exxx. There is however also an alternative to the DOS ROM at #Exxx and that is the AtoMMC rom at #Exxx. The control bit to toggle between those ROMS is bit 2 of #BFFE. If this bit is 0 then the DOS ROM is active, with this bit set to 1 the AtoMMC ROM is active. Then there is another option for the address space #A00 - #AFF; this area is used by the non-modified Atom DOS FDC board. But if you don't use the DOS then you don't need this gap in your memory. So it is also configurable: bit 1 of #BFFE disables RAM at #A00-#AFF when set to 0 and enables RAM here when set to 1. So, when you use the AtoMMC you can set the bits 2 and 1 of #BFFE to 1 and have the full 32k lower memory space without a gap and the AtoMMC ROM enabled at #Exxx. And this is where the magical 6 comes from. Enabling AtoMMC + no gap is done by entering ?#BFFE=6. To enable the Atom DOS with a gap at #Axx you enter ?#BFFE=0; Those bits are "sticky" so they are not reset to 0 when the Atom is reset. They only are set to zero at a power on of the Atom and when you clear these bits in software.
In an Atom with AtoMMC installed we can tweak the CPLD on the Yarrb board to have the value 6 in register #BFFE by default which will always automatically enable the AtoMMC at power on. This can be achieved by changing the VHDL source and re-program the CPLD.


I hope this explanation makes it a bit more clear what the relationship between the AtoMMC and Yarrb is. You can have either one of them, but the combinations gives you a powerful Atom without serious modifications.

If you have further questions then don’t hesitate to ask them here.
Attachments
YARRB-memory-map.pdf
Memory maps in the Yarrb memory profiles.
(22.77 KiB) Downloaded 50 times
ROMRAM-bits.pdf
The configuration bits at #BFFE and #BFFF explained.
(90.17 KiB) Downloaded 43 times
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marcusjambler
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Re: Yarrb - redesigned

Post by marcusjambler » Sat Dec 21, 2019 9:42 pm

Thanks Roland =D> Thats a big help.
I think I need to re-program my other YARRB board that hangs when I attach the ATOMMC SD card

Marcus

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roland
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Re: Yarrb - redesigned

Post by roland » Sat Dec 21, 2019 9:48 pm

marcusjambler wrote:
Sat Dec 21, 2019 9:42 pm
I think I need to re-program my other YARRB board that hangs when I attach the ATOMMC SD card
If the AtoMMC is correctly attached then the Atom should not hang in any configuration. I noticed that my Atom did work with JP4 (first Yarrb version) to either position but AtoMMC was not working with the jumper in position 1-2 but it was in position 2-3 (i.e. left). Can you check that?
Also cleaning the clock signal by adding a 100 - 150Ω resistor in the wire from pin 13 of IC44 to pin 37 of the 6502 socket will improve stability of your Atom.
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Re: Yarrb - redesigned

Post by marcusjambler » Sat Dec 21, 2019 9:51 pm

If the AtoMMC is correctly attached then the Atom should not hang in any configuration. I noticed that my Atom did work with JP4 (first Yarrb version) to either position but AtoMMC was not working with the jumper in position 1-2 but it was in position 2-3 (i.e. left). Can you check that?
Also cleaning the clock signal by adding a 100 - 150Ω resistor in the wire from pin 13 of IC44 to pin 37 of the 6502 socket will improve stability of your Atom.
I will do this over the Christmas break and report back.

Marcus

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Re: Yarrb - redesigned

Post by balford » Mon Dec 23, 2019 1:43 am

@Roland - PM sent- apologies for the lateness. AtoMMC active on reset, please, as I forgot to mention that in my PM 🙂

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Re: Yarrb - redesigned

Post by roland » Mon Dec 23, 2019 9:49 am

I got a question about Yarrb and the Acorn Colour Board, do they fit in one Atom?
The answer is: unfortunately not, the do not fit next to each other [-X


I don't have any colour boards in my Atom, but if somebody who has a colour board fitted inside the Atom and a Yarrb board, please post a picture of it here [-o<
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Re: Yarrb - redesigned

Post by marcusjambler » Mon Dec 30, 2019 9:20 pm

My YARRB 2 arrived today.

Just need to dig out my other ATOM now :D

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Re: Yarrb - redesigned

Post by anightin » Tue Dec 31, 2019 1:00 pm

My YARRB 2 arrived today, waiting to be fitted to Atom no.3 -- thanks Roland =D>
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roland
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Re: Yarrb - redesigned

Post by roland » Tue Dec 31, 2019 2:34 pm

Thanks for confirming that you (both Marcus and Andy) have received the board. Enjoy your board and all good wishes for 2020.
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KenLowe
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Re: Yarrb - redesigned

Post by KenLowe » Tue Dec 31, 2019 3:15 pm

Looking forward to receiving mine. I'm currently on holiday, so I'll probably need to pick it up from the delivery office when I get back next week.

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1024MAK
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Re: Yarrb - redesigned

Post by 1024MAK » Tue Jan 07, 2020 12:41 am

Mine arrived on Monday (see here).

Thank you Roland =D>

Mark

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Re: Yarrb - redesigned

Post by balford » Wed Jan 22, 2020 12:02 am

Mine arrived today, and is currently performing sterling service helping my Atom run Manic Miner.

Thank you again Roland!

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Re: Yarrb - redesigned

Post by roland » Wed Jan 22, 2020 8:11 am

Glad to hear that it arrived and works. Enjoy your powerful Atom :D
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Re: Yarrb - redesigned

Post by roland » Sun Feb 09, 2020 12:13 pm

Another one for the hall of shame (a.k.a. stupid mistakes like in this topic):

I am preparing an Atom with a Yarrb2 board. It was working in the original configuration so I removed all the IC's that are not longer necessary and installed the Yarrb2 board. And guess what: the Atom did not start. :shock: Just a scrambled screen. Testing, probing with scope, all seemed all right. A15, A13 and A12 are stable at high level, A14 is toggling. So .... the CPU is reading from pages at #Fxxx and #Bxxx. No doubt that it hangs waiting for the VIA in the print routine.

I took out ICE-T65 to make sure it is .... yes it is. Why? Check the CS from the VIA: it's continuously high. How comes ..... ? IC23 is removed. RYOFACI* Roland :!: Where did you ever read to remove IC23?

IC23 is used to decode 4K blocks in the upper memory area. Although many of those blocks are not on the Atom main board any more, some of them still are, like #8xxx and #9xxx (video memory) and also #Bxxx (the I/O block). So this decoder is still crucial for the Atom to work :oops:

Point of this post: don't be afraid to make mistakes, make people make them ..... but read the instructions carefully and you may avoid them :lol:


* Read Your Own Fine And Clear Instructions
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Re: Yarrb - redesigned

Post by eXne » Wed Feb 12, 2020 2:18 pm

My Yarrb board arrived today.
Had to be quick as my cat thought ic u4, ST39SF01A, was something to play with..
Weekend project coming up, thx Roland
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Re: Yarrb - redesigned

Post by roland » Wed Feb 12, 2020 3:11 pm

eXne wrote:
Wed Feb 12, 2020 2:18 pm
Had to be quick as my cat thought ic u4, ST39SF01A, was something to play with..
For cats it is something to play with ... what else can (s)he do with it :lol:
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Re: Yarrb - redesigned

Post by cjm » Thu Mar 26, 2020 9:19 am

My Yarrb arrived - connected and working.
Pin 10 on IC44 managed to connect to the side of the socket and resulted in a mournful ctrl-g sound - my fault - I just needed to bend it a bit more.
The Atom is now busy calculating the first 100 digits of pi using BBC basic - I need an AtoMMC now!
Many thanks to roland, this is a great project.
Atom | BBC Model B | RPi | Software professional | Electronics hobbyist

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Re: Yarrb - redesigned

Post by marcusjambler » Thu Mar 26, 2020 9:47 am

cleaning the clock signal by adding a 100 - 150Ω resistor in the wire from pin 13 of IC44 to pin 37 of the 6502 socket will improve stability of your Atom.
Done.... Atom now running great :D

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Re: Yarrb - redesigned

Post by reedas » Tue Apr 21, 2020 3:29 pm

Hi Roland,

Do you have any of the YARRB2 boards left? If not are you planning to order more? Although my atom is up and running now the Timedata 32k board gets quite toasty and I feel the need to cool the system down a bit.

Also is it still possible to get the atommc/sddos boards?

Thanks in hope
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roland
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Re: Yarrb - redesigned

Post by roland » Tue Apr 21, 2020 4:07 pm

No, there are no Yarrb2 boards available at the moment. I am willing to order a new batch if there is more demand for it. So people, if there are one or two extra requests for a Yarrb2 then I will order a new batch of five.

You can ask Sir Morris if he has AtoMMC boards available. I don't have any left.
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Re: Yarrb - redesigned

Post by BillG » Fri Apr 24, 2020 10:27 am

Hi,

I'd be very interested in trying the new Yarrb as well, so count me in if there are more boards made

cheers

Bill

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Re: Yarrb - redesigned

Post by reedas » Wed Apr 29, 2020 8:13 pm

roland wrote:
Tue Apr 21, 2020 4:07 pm

You can ask Sir Morris if he has AtoMMC boards available. I don't have any left.
@SirMorris, Do you have an ATOMMC board left, I am trying to see if I can adapt your PIC code to run on a cypress psoc6 ARM dev board via the sk8 and using SDDOS/ATOMMC rom,
cy8ckitproto.jpg
but it would obviously be a lot easier/quicker if you do have one that your willing to part with. And in the same request do you have a ;+ issue 4 keycap I seem to have mislaid mine somewhere :oops:
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Re: Yarrb - redesigned

Post by highfell » Tue May 05, 2020 9:16 am

Hi Roland

I could well be in the market for one of your new YARRB.

I took half of your earlier advice (get yourself a Rom/Ram board & a AtoMMC board) and got myself an AtoMMC board from Sir Morris. It works as it should BUT it sits in IC24 where my programmable Rom chip was and I didn’t realise that I wouldn’t be able to load any of the Roms anymore and execute them :(

Sir Charlie and I are currently in email correspondence about shifting his board into the #E000 location. He has some super creative thoughts and I think I understand them, but they may be beyond my soldering skills which are poor (essentially I don’t trust myself and I have an old unwieldy soldering iron). What is cool is that all of this is slowly building up/replenishing my memory banks with the detailed knowledge of how the Atom works :D .

However an easier option appears to get a ROM/RAM board, hence this post.

I am though going to do some tinkering (in the meantime), and thought I would remove his MMC EPROM from the #A0000 location and insert it into the Dos rom socket of my Disk Drive unit and see if I can get any success loading and saving programmes from there.

I can’t pm you, so could you pm me and we can chat offline.

Many thanks

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Re: Yarrb - redesigned

Post by hoglet » Tue May 05, 2020 9:25 am

highfell wrote:
Tue May 05, 2020 9:16 am
I am though going to do some tinkering (in the meantime), and thought I would remove his MMC EPROM from the #A0000 location and insert it into the Dos rom socket of my Disk Drive unit and see if I can get any success loading and saving programmes from there.
I'm sure you already know this, but I'll say it anyway.... You will need a different AtoMMC ROM that has been designed to run at #E000.

Dave

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