Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

peddle your acorn wares here!
Forum rules
You're welcome to trade Acorn-related stuff with other forum members here - the rule of thumb to follow when trading, is that items or services offered should be of interest to our Acorn community. Do NOT use multiple accounts - please trade with your regular (and only) forum account. If you're giving items away, please make it clear if you would be unhappy with the recipient selling on some or all of the items. Similarly, please ensure that the giver is comfortable with you re-selling items you have accepted as a gift. We cannot be held responsible for what happens in these trading forums or for deals done via PM. This must be done at your own risk. If you aren't comfortable with this - make the trade via an alternative site which can apply safeguards of their own. Be sensible - if someone approaches you to trade via PM who is not posting in the public forums, this may be a sign that they are not entirely what they seem. Please report it to the moderators if you receive an unsolicited message from anyone suspicious, so that it can be investigated and hopefully stop anyone being taken advantage of. This forum is not for advertising items you have for sale on ebay or other third party marketplaces.
Post Reply
User avatar
TheCorfiot
Posts: 671
Joined: Mon Jan 08, 2007 5:22 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by TheCorfiot » Mon Jan 05, 2015 7:01 pm

Boards look great, thx for your hard work over the holiday season and through illness.

Are you far from posting them out?

Cheers :)

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Mon Jan 05, 2015 11:44 pm

Right, I was boxing some up at the weekend and I have a couple which didn't test out so I've just cut some new BIST (Built in self test) code and re-flashing them all which isn't all that quick. I've got a handful done this evening and I'm going to do a few more before bed.
So at least some should get posted tomorrow.

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Tue Jan 06, 2015 10:02 pm

A load of boxes went out today, not all, but they are shipping.

I'll be sending more out tomorrow.

User avatar
1024MAK
Posts: 9698
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by 1024MAK » Tue Jan 06, 2015 10:06 pm

Great news :D

Mark

User avatar
TheCorfiot
Posts: 671
Joined: Mon Jan 08, 2007 5:22 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by TheCorfiot » Wed Jan 07, 2015 3:49 am

Thats Fantastic

Thank you :)

User avatar
sydney
Posts: 2471
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by sydney » Wed Jan 07, 2015 2:59 pm

Postman has just been! Thank you very much Jason!
Off to pick my daughter up from school then I'm sure I'll have a bit of spare time to try this out. I Probably won't have time to get the dremel out though so will the 2nd processor version of elite work with the beeb+copro?

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Wed Jan 07, 2015 8:00 pm

Will ship some more tomorrow. There's no particular order, just whatever cardboard box comes of the top of the pile.

skjerk
Posts: 10
Joined: Sun Jan 04, 2015 8:47 pm
Location: Copenhagen, Denmark
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by skjerk » Wed Jan 07, 2015 9:19 pm

Hi Jason,

Please sign me up for one (the big one!)

Cheers, Carsten

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Thu Jan 08, 2015 8:22 am

Going to pause shipping more units until I've investigated
stability reports. Bear with me. I'll report back tonight.
I'd rather get these out to everyone in good order.

skjerk
Posts: 10
Joined: Sun Jan 04, 2015 8:47 pm
Location: Copenhagen, Denmark
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by skjerk » Thu Jan 08, 2015 8:28 am

No problem :-)

Better safe than sorry !

Cheers

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Fri Jan 09, 2015 12:51 am

Update:

After staying up until 02:30 last night, and later than I wanted tonight,
I have finally tamed some of the very unstable units that I have witheld.
By adding a decoupling capacitor across the level shifter, normality
has been resumed and I'm crusing at an improbability level of 1:1.

I don't have enough to fit to every board so I'll order some in and add
one to the remaining units over the weekend and post them out on
Monday.

I still haven't worked out why the prototypes that Hoglet and I have
been using for the last month don't exhibit this problem.
I also don't know why I didn't sprinkle more decoupling in that corner
of the board..

Sorry for the delay, but at least we have working boards to look forward
to.

User avatar
DutchAcorn
Posts: 2161
Joined: Fri Mar 21, 2014 9:56 am
Location: Maarn, Netherlands
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by DutchAcorn » Fri Jan 09, 2015 7:38 am

flynnjs wrote:Update:

After staying up until 02:30 last night, and later than I wanted tonight,
I have finally tamed some of the very unstable units that I have witheld.
Please don't stress yourself Jason, all this retro-stuff is meant to be fun, not stress.
By adding a decoupling capacitor across the level shifter, normality
has been resumed and I'm crusing at an improbability level of 1:1.
After that "Anything you still can't cope with is therefore your own problem." :D

To whom have you shipped out now? If this solves instability perhaps you can post some instructions how to add what type of capacitor where?

Thanks for all the hard work!

Paul
Paul

Image

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Fri Jan 09, 2015 7:53 am

I've shipped out 10 boxes and the rest of batch one are piled up
in the corner of my living room getting the minor comment from
SWMBO "when are you going to post those?" :mrgreen:

The engineering fix looks like this:
cap-fix.png
But a final fix will be cleaner than this and I'll apply them over
the weekend and post on Monday.

The unit pictured above happily ran a stress test for 6 hours
over night last night, so I'm confident that this is the right fix.

People who have already received theirs have the following options:
1) Send back to me to apply capacitor
2) If very confident on own ability, add their own capacitor
3) Bring it to the Halifax meeting at the end of month.

If you need to send it back to me then the return address is on
the label on the back of the box it came in.

User avatar
danielj
Posts: 7844
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by danielj » Fri Jan 09, 2015 10:04 am

Thanks Jason, I've just picked mine up - 220nf capacitor? Which pins have you got it across - it looks like more than one on each side?

d.

User avatar
TheCorfiot
Posts: 671
Joined: Mon Jan 08, 2007 5:22 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by TheCorfiot » Fri Jan 09, 2015 10:27 am

Simply superb Jason

Thanks for all your efforts...

:)

User avatar
jbnbeeb
Posts: 529
Joined: Sat Apr 03, 2010 8:16 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by jbnbeeb » Fri Jan 09, 2015 10:30 am

Bring it to the Halifax meeting at the end of month.

Hi Jason - I'll take this option please :) That said I haven't observed any instability, but haven't used it very much yet so perhaps best to go with the fix.

Out of curiosity - what is the nature of the instability and how does the decoupling capacitor fix it..?
I'm going to...
ABUG Cambridge May 15-17th 2020
Image

poink
Posts: 963
Joined: Tue Mar 01, 2011 10:27 am
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by poink » Fri Jan 09, 2015 1:36 pm

jbnbeeb wrote:Out of curiosity - what is the nature of the instability and how does the decoupling capacitor fix it..?
I'm guessing it's the usual reason for decoupling caps.

When components switch, they tend to pull more power than usual. There are limits on how quickly more power can be provided from the power source due to the inductance of the wiring/PCB tracks/power rails. Thus the power[1] available to other components drops in the vicinity of the switching component. If this drops sufficiently, then there will be misbehaviour - things losing state; things not registering logic levels correctly, etc., The exact symptoms are unpredictable, down to the specific components and wiring involved.

The decoupling capacitor fixes this by acting as a tiny, local rechargeable battery, supplying power as necessary. It's called a decoupling capacitor because it 'decouples' the power supply of a component from other components.

The size isn't particularly sensitive. It needs to be large enough to cope with the transients, but a discharged capacitor (eg., at switch on) looks like a short to ground, which causes problems if they're too big. A 0.1uF capacitor across the power pins of every IC is typical practice for most digital circuits. 0.22uF is definitely reasonable, especially given there have been problems.

[1] We usually say that the component switching needs more current, leading to - by P=IV - a localised drop in voltage.

User avatar
BigEd
Posts: 2833
Joined: Sun Jan 24, 2010 10:24 am
Location: West
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by BigEd » Fri Jan 09, 2015 4:11 pm

danielj wrote:Thanks Jason, I've just picked mine up - 220nf capacitor? Which pins have you got it across - it looks like more than one on each side?
Indeed, it's a pair of pins at both ends, because it just so happens that the supply pins are doubled. Might make the soldering a bit easier.

User avatar
danielj
Posts: 7844
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by danielj » Fri Jan 09, 2015 4:28 pm

Job's a good'un. Cheers Ed. I've got some 220nfs in my box of bits. Z80 beeb-ahoy!

d.

User avatar
1024MAK
Posts: 9698
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by 1024MAK » Fri Jan 09, 2015 4:53 pm

Ahh, explaining decoupling. Always fun :lol:

There is some info buried in a thread about a second user port that Sweh was building (linky, the more interesting bit is here).

Mark

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Sat Jan 10, 2015 12:09 am

There will be a minimum value that will be needed for it to have the desired effect.
I had a bag of 220nF to hand but the SMD decoupling capacitors sprinkled around
the board are all 100nF.

If I can find a neat way to use more of the 100nF SMDs then I will do so.
I'll try this first thing tomorrow. If not, I'll zip out and get a bag of 100x
220nF from Rapid so I've got the parts needed to complete the work
before Monday.

jbnbeeb, you make have been lucky like Hoglet and myself who experienced
no instability on the prototypes. Others who have already received theirs
may be getting occasional glitches but infrequent enough that I thought
they were good to ship.

Fitting your own caps: Pin 23 and/or 24 (which are alread connected together
and carry 3v3) need to be decoupled to GND. In my photo I connected them
both to one leg of the cap and the other leg goes to pins 11 and 12 which are
both ground. Having each leg of the capacitor on two pins makes it a slightly
easier for those that might not have a really fine tipped soldering iron.

I would prefer people let me do it if they are in any way unsure so as not to
incur and damage which could be difficult to recover from.

User avatar
CMcDougall
Posts: 6973
Joined: Wed Feb 02, 2005 3:13 pm
Location: Shadow in a Valley of Scotland
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by CMcDougall » Sat Jan 10, 2015 12:21 am

flynnjs wrote:I've shipped out 10 boxes.
many Thanks for this Jason =D> =D> =D> my wife opened mine on Wednesday, as I totally forgot what the postman was bringing me :? ... S/N 024 :D

might have 2 seconds tomorrow night to give it a go, but before I do I read in other thread the 4 dip switches are to be set to off for Elite. Is the off position when the little white higher bits are nearer the big square chip? sorry for being a numpty #-o , as mine are already set nearer big square chip, but on that side it says on switch "ON DIP", just want to confirm first 8)

Cheers again, Col.

EDIT, just read your above post while posting, ref 'fitting your own caps', I may also be lucky too :P
ImageImageImage

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Mon Jan 12, 2015 6:59 pm

The remainder of this batch have passed testing and been boxed up and sent.

Thanks for everyone's support.

User avatar
TheCorfiot
Posts: 671
Joined: Mon Jan 08, 2007 5:22 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by TheCorfiot » Mon Jan 12, 2015 7:09 pm

Thank you sir ;)

User avatar
jbnbeeb
Posts: 529
Joined: Sat Apr 03, 2010 8:16 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by jbnbeeb » Mon Jan 12, 2015 10:17 pm

jbnbeeb, you make have been lucky like Hoglet and myself who experienced
no instability on the prototypes
Hi Jason, would it be still worth applying the capacitors to "make sure" my co-pro will be stable?
I'm going to...
ABUG Cambridge May 15-17th 2020
Image

iainjh
Posts: 349
Joined: Mon May 14, 2012 11:18 am
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by iainjh » Mon Jan 12, 2015 11:04 pm

thanks Jason! :)

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Mon Jan 12, 2015 11:25 pm

Jason,
I can add a cap at the end of the month if you want.

User avatar
berendvosmer
Posts: 18
Joined: Mon Jan 12, 2015 9:52 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by berendvosmer » Tue Jan 13, 2015 12:54 pm

I've just joined and I haven't even introduced myself properly yet, but wondering whether these are still available.

I've become particularly fascinated with the z80 coprocessor and running cp/m.

If possible I'd like to have the B model.

Very impressed with the work done, kudos to Dave and the others contributing.

User avatar
flynnjs
Posts: 831
Joined: Tue Jul 06, 2010 9:33 pm
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by flynnjs » Tue Jan 13, 2015 9:44 pm

Batch 2 people PLEASE DO NOT SEND PAYMENT.
I'm currently undecided if/when a second run will happen. Those that have
sent payment already will receive boards but I currently have no more.

User avatar
roland
Posts: 3624
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Post by roland » Tue Jan 13, 2015 9:49 pm

Question: for those people who still want one, is this

It's a GODIL GOP XC3S200 module:
http://www.oho-elektronik.de/pics/UM_XC3S200.pdf

still a good alternative?
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

Post Reply