Mockingchick: An Apple II Mockingboard clone (hopefully!)

Charlie

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Ahhh, something small and sweet arrived today:
MockingChickPCB front.jpgMockingChickPCB back.jpg
Mockingchick PCB

And they grow so fast:
MockingChick front.jpgMockingChick back.jpg
Nearly Done

Here's hoping it becomes a useful member of society. I'm waiting on the stereo sound socket to arrive. Once soldered in I hope it turns out to be functional... If so I have a few boards, but be warned; because the board is pretty well packed it's a somewhat tricky job to solder.



Fingers Crossed
 
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stereo AY audio?
also why does it need two via's? im curious


what is it? (add cat from red dwarf here)
 
It's a Sound card for the Apple II's... Need 2 6522 VIA's to interface the both AY's to the Apple Bus slot

:)


Charles.... Looking good my friend, hope it works ;)
 
I recomend picking up an NTSC iie Roy, you will get proper NTSC Woz Colour, read up on it, pretty impressive design.
If you need a 240v supply for it i can help you out.

They are fascinating machines for hackers, lots of projects to fill the slots, and the software is pretty cool too.
See Charlie's Pi interface.. works really well.

:)
 
Nice one, Charlie!
Does the IIGS benefit from this?
Man, I'm really beginning to itch for a IIe Platinum.
 
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Hi chaps,
Thanks for the replies. I'll be frank and admit I'm very new to Apple hardware - I tend to have an unfortunate habit of jumping right in with a system that's new to me:
"Well that's all well and good but I want x,y,z to make it properly nice to play with... Oh, x,y,z are that hard to find and THAT expensive? B*gger that I'll make my own." Having a relatively simple expansion system and being typically expensive Apple kit has spurred me on a bit.
Anyway I see no reason why a Mockingboard shouldn't work in a IIgs but I have heard it's very hit and miss... I've still hardly touched mine as I have been busy getting my IIe up to scratch.

MockingChick:
Well, the correct stereo sockets have arrived so I've now tested it and... No dice, sadly. "My" design, such as it is, has no amplification on board to keep component cost and size down but with external amplification all I'm getting is a bit of system hum.
Both 6522s are a little warm with power applied but if I remember correctly from my Beebs that's not unusual. I am, however, not going to make the mistake I made with my A2Pi board by spending hours fruitlessly debugging to the point where I made a fresh design only to discover it was just a faulty IC that was to blame. I'll just do a sanity check on the power lines to be sure I'm not shorting anything and source some replacement ICs first...
...having said that I'm well aware I'm in over my head with regard to this kind of stuff so if anyone feels like casting an eye over my "simple" board design I'd be grateful. AmiOracle thread).
 
An update:
New parts on the way... but I've decided the MockingChick's current design is rubbish! Also there's a few mistakes on the PCB, and applying patch wires is so messy.
Rather than continue mashing bits of other designs together for my 'quick fix' I've actually bothered to engage some brain cells and do a proper design of my own to squash mistakes, make the board more functional, and fix some long running Mockingboard issues.

Mk2 Top.pngMk2 PCB.pngMk2 Bottom.png
Mk2 Board Layout

Goals:
Smallest possible PCB (cost)
Better physical compatibility with cards in a lower slot
A little easier to solder
More coherent and hopefully stable schematic
Better labelling
Audio jack will allow automatic switching between internal and external output

Also:
Headers for optional plug in Amplifier module
Long running Mockingboard reversed stereo fixed
A system beep pass-through that doesn't render the board mono
Long standing Mockingboard reset bug fixed

Sadly:
No speech; the ICs are stupidly expensive and it's just not worth the PCB real estate when I can't see the sockets getting populated.
Why not use one 6522? Very good question, the 6522 has more than enough IO to drive two sound chips but as I have no idea how the software works I didn't want to introduce compatibility issues, so stuck with the traditional design for now.

So...
One last check over, final fiddle with some of the labels, and yet another order sent to Seeed... fingers and toes crossed!
 
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An update:

I think it's safe to say I'm fairly clueless at this PCB designing lark... Can't get my prototype to work, killed my Apple IIe, house slowly filling with coasters that look suspiciously like PCBs...

Ho-hum, marching on regardless. :)

I'm up to a Mk4 version of the Mockingchick. Finally got all the ICs to fit on one side of the board, keep the size down to a minimum and managed to route it. Phew! Piccies below:
MK4board.jpgMK4text.png
MK4 MockingChick
Features:
Smallest and so cheapest PCB I can fit a full stereo Mockingboard clone on to.
Finally got all the ICs to fit on one side of the board so no chance of issues with boards in a lower slot.
Minimal component count to keep cost down. (diodes and R3 can be omitted with little loss)
Line out via 3.5mm audio jack that will line up with a knockout if using the default slot (4).
System sound pass-through header. (R3 either a resistor of your choice or use a variable pot)
Optional 4 watt amplified stereo out header for mounting internal speakers
Internal amplified audio auto shut-off if 3.5mm out in use.
Left and Right channels not reversed with this version.
No reset bug here!

For any who are interested I incorporated a header for one of these 4w stereo audio amps based on the PAM8403:
sku_347324_2.jpg
PAM8403 Board

Cheap as chips at 99p a pop if you shop around. Surprisingly solid results, and both smaller and much cheaper than anything I could have incorporated in to this board. Don't need? Don't bother to fit. Have better plans for the headers? Be my guest.

No, this board isn't manufactured, yet. As my previous PCBs have proven very reluctant to get working I'd very much appreciate some advice on my schematic / layout before I inadvertently order another run of coasters.

Links to:
.zip file containing schematic and PCB files for MK4 board (and experimental version using Yamaha YMZ284s instead of AY-3-8913s)
Schematics for two common versions of the Mockingboard to compare with mine.
...for anyone who's feeling kind enough to do a sanity check for me, or anyone curious.

(I'm aware of the lack of decoupling caps for the ICs. They are present in a small revision not shown here)

Many thanks in advance. :D
 

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I do hope the finishing line is in sight:

MockingChick MK4
MockingChicckMK4front.jpgMockingChicckMK4back.jpg
MockingChick MK4

Yep, those ICs are pretty tightly packed. The board is really designed for the ICs to be soldered directly but this initial version uses pinstrip headers so I can debug any remaining issues (I hope not!) and have a test-bed for components on shipped versions. (assuming there's any interest) The whole thing sits very nicely in slot 4, and no conflicts with slots 3 and 5.
No errors from my IIe this time, but I've yet to test it software as I have a dead FDD/Card ATM. *Sigh* Will post the news once I have a working system.
 
Awesome awesome awesome!

:blush
Thanks for the very kind comment! I'm a bit frustrated because this little project has been rather more tricky that I hoped/expected, and now I sincerely hope I've cracked it I'd like to go test the darn thing. But no current way to load software without a working floppy. I guess I could ADTPro over audio but that would be painful!
 
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Didn't we trade a super serial? Ps I tried over audio. It works -and is not that slow!

:)


ps push push eh.
 
Small Update:
As my Apple II is with the most excellent TC in the hope he can bring it back to life my MockingChick project is stalled with the hopefully final prototype ready for testing. So I thought I would have a crack at a manual / assembly guide.

Feel free to have a look, feedback welcome.


 
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The postman has been good to me today:

20170906_141337.jpg
Replacement Apple IIe Motherboard

Having stupidly killed my Platinum's motherboard, and Humpty has refused to be put back together again, my 'pute has been officially brain dead for a bit. Most frustrating, especially as my first Mockingchick has been assembled and ready for testing for some time. I do hope the pesky thing works after all this.
Yes, it's a IIe, not a Platinum, board but as it's got a 65C02 in it I'm hopeful it will be functionally the same. Interestingly said 65C02 is a 10mhz WDC part. I understood Apple II's don't like these CPU's without moding; none noted but the seller claimed it's fully working and "refurbished" so let's see. Every IC is in a socket, which is nice, but equally every socket has been hand soldered so I guess this board has had a lot of work. Thankfully the PCB looks in good shape and I have a ready supply of spares. :oops:

Happy days, I do hope I'll have some good news to report shortly.
 
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If when you boot it you get an ' Apple iie ' Logo not Apple IIe then you have an enhanced ROM set which is 100% compatible with the Platinum, if not we need to blow you some new ROM's

:)
 
Thanks Bas. :)

I finally let my ADAM alone long enough to put the 'new' board in my Apple II. The good news is it works and at first glance seems to be a IIe enhanced board, excellent!

Right, Mockingchick:
No sound from either the line out or amp out. Blast, I could have sworn I'd ironed out all the bugs.
Testing with a Mockingboard hacked version of Zaxxon, just in case I'll write an official Mockingboard demo disc...

I couldn't make my mind up between a 7404 or 7405 for the logic, makes no odds which I use except no activity LED with a 7405.
As I have loads of 6522s and AY chips I tried swapping a few, still no sound.
Too stingy with the decoupling caps? Still no joy after adding some direct to the ICs.
Did I get the diodes the wrong way round? Removing them didn't help.

One of the schematics I've seen has a load of passives round the 7404/5 for what looks to be an attempt at getting a better clock signal. I might try bodging that in but otherwise I'm sorry to say I'm out of ideas. Really frustrating, I'd swear building one of these boards should be pretty straightforward but I'm obviously missing something.
 
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good news re the enhanced board working!

and... good luck with the mockingchick. any way to further test the board routing and addressing? btw why does it have to be slot 4?
 
Ahh... IIe fully reassembled and working well. Sadly the same can't be said for my Mockingboard clone. (grumble)

I do hope it's just the only Mockingboard aware software I have is a hacked version of Zaxxon which isn't working for some eason, and other software will be fine. Sadly I'm not hopeful.

Hi Iain,
To the best of my knowledge all Mockingboards will work fine in any slot but slot 4 is recommended because some software either doesn't auto-detect or ask and just assumes. Not in slot 4? No show.
 
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