Posts by ljmarent

Yeah, sure, wear-out is a thing, but it's three months old, the problem's been there since it was bought new.

So statistically, lower probability of a wear-out, though still fully possible, bath-tub curve and all that.

As it still could be a bad wire or contact, I'm testing it on a Windows machine, to see if it is the mouse or the interaction with the Micromys V5 that is the issue.

I can build a PS/2 connector test jig to test the idea of a wire being disconnected or high resistance at power-up,

and we should see a similar 'odd' behaviour, though I can't imagine such a mechanism.
That doesn't mean that all of reality is within the scope of my imagination. Testing is better.

Right now...I'm thinking:
Either this mouse is very sensitive to the PS/2 supply voltage requirement of +4.5V <> +5.5V
It's cord is extra thin, so it may suffer meaningful voltage loss over 30AWG wires and the Amiga's 4.7R internal resistance.
So maybe it's not POR'ing correctly ?
Or...

It 'needs something' at power-on \ initialization that it's not getting from Micromys V5.

and as a result it's sending back data that makes no sense, or is not synchronizing with the Micromys V5.

Found someone online talking about the trouble they have had with ensuring that their PS/2 mouse driver is synchronized with their mouse:
"The trick i found to fix this is to use the fact that byte 0 is supposed to have bit 3 always set. So when i receive a byte that is supposed to be #0 with bit 3 cleared, i simply discard it and assume byte 0 will come next. As long as you're on synch, this is completely transparent, and when the mouse comes out of synch, only a few events are sufficient to restore synchronization (especially fast with steady clicks)"

Not aware of what Micromys V5 does to detect and correct out of sync condition, or if it uses PS/2 mouse streaming or a different mode of operation.

Good news,

I ordered a couple alternative PS/2 mice from Amazon.

For the last couple days, I've been using a:
Make: Perixx
PERIMICE-209
Part: M-868

So far, I've not seen the 'odd' mouse behaviour...which is great as that was getting frustrating
I'm going to try the Adesso PS/2 mouse on an older Windows machine over a week, and see if I can get it to behave 'odd' at start-up. I feel obliged to help narrow down if this is simply a defective mouse or possibly a Micromys V5 compatibility issue with that mouse at startup.

Quote from Jens

and while you're at disassembling anyway, why don't you launch the system without the case, just with a normal A500 PSU

"I've completed a full tear-down and reassembly"

Umm...it's all back together again...and funny...did the 'odd' mouse thing described above on first boot

I'm away house shopping today, but "I'll be back"

How about this?
I have the first A500 board, the one where I first saw the issue...
I can stuff it back in it's ugly old plastic coffin, with a second Indivision ECS V2 and a second ACE2b.
Alas...I don't have a second ACA500+ ... so I'll move this ACA500+ and this Micromys over and whip out my decrepit Amiga power brick.

Having already seen this behaviour with the Micromys on that board, using the described setup, I'm reasonably confident "the walk" won't be for nothing, as the odd behaviour is sure to show up...

For a couple of months, this system ran on my desk like this; while I waited for the CM1500 case to show up...

Powered by the stock power supply...
And I never said a word about the mouse, because, who's gonna show a picture of a system running like that and say "Help me Obi-Wan"

I'd point out that the ACA500+, ACE2b and Indivision ECS V2 have been 'otherwise happy' to live in the case and consume the power that I've provided them...old A500 plastic box, logic board screwed into an A500 bottom shield, new CM1500 case, old Commodore PSU, new PSU made by me, they all worked the same. Having looked at the support history of all the iComp designed contraptions involved here, the Micromys does not seem like it should be anywhere near the 'weakest link'. There are so many other iComp contraptions in this setup that are sensitive to power, shielding, grounding, that they would likely be going haywire, if there was such a problem.

"Fault Isolation" is indeed a good diagnostic practice, but it can also lead to reduction to the absurd if you let it.

I'm going to get a couple other PS/2 mice and start there, because I think that really would be the simplest thing first.
If it turns out it's the mouse, my best guess is it's protocol related, I'll send it to you, so you can see what it does differently, and maybe increase Micromys compatibility with what's available on the market...which isn't a whole lot these days.

If the problem continues with other mice, then I'll proceed with the second A500 in a plastic box as outlined above.

Chat you in a couple days

Quote from Jens

I'd like to see the grounding/shielding efforts before I do any more support work here.

Okay, totally willing to help on my end.
I've completed a full tear-down and reassembly taking a hundred or so photos of areas of interest.

Your request is 'open ended', there is no way for me to definitively answer, but I'll do my best by showing some of the grounding and shielding and if there is a more specific aspect you'd like to see, I will change focus to that.

Edited, factory lower shield

Factory insulator

Board-in connector shield screws

Star-Topology grounds wires connecting A500 Logic Board and Indivision ECS V2 to the ground at system power entry.

forum.icomp.de/core/index.php?attachment/2384/

Mouse being used is Adesso HC-3003PS, just in case "that's a thing"
I mean ... I suppose the mouse itself could wake up on the wrong side of the PS\2 bed and something goes wrong there..

Unfortunately, I only have one PS\2 mouse....
{adds second PS\2 mouse to shopping list}

While I disassemble to take more pictures.

4.98V - 4.83V = 0.15V

0.15V / 4.7R = 31.9mA (ignoring connector losses)

What is the expected load of the Micromys V5 contraption ?

Okay, so I made a pass-through to measure the voltage

Setup

Results

4.83V DC

Please keep in mind, you asked me:
"Do you have a multimeter so you can measure the 5V at the joystick port?"

The most immediate interpretation of that is:
"Please stick your multimeter probes into the joystick port and measure the 5V rail"
which...does imply no load, but there we go..all fixed.

I am happy to build jigs, and measure things, and wheel the lab up here if need be.

Okay...I'll make an adapter that goes in between with the Micromys loading the line

Truth be told...it's far more an iComp computer than an Amiga at this point

I whipped up a little DB9 adapter to make getting the probe clips on easier

Equipment

Result

4.98V DC

Now...there could be a tiny loss due to the 3m of probe wire and the pinch probes and the DB9 connector...
But it's a pretty good rendition of +5V DC

The power supply in this case is just below the multimeter.
Despite its appearance, It is not an ATX PSU, and it has independent switch mode supplies for +5V, +12V and -12V rails, as well as ample capacity (10A on the +5V rail)

I have the same trouble when I use an original Amiga PSU to power this system.

The A500 has an Indivision ECS V2, ACE2b, Lyra3 and ACA500+, running OS 3.2, not sure if any of those 'variables' could be contributing ?

Amiga 500

I've not been using my Micromys V5 very much, but now that the system I built for it is complete, and I'm using it regularly, I've noticed an intermittent problem.

1 out of ever 3 power cycles roughly.

On power-up, once the Amiga has finished loading Workbench, the pointer is found in the top left corner of the screen.

As soon as I try to move the mouse, the pointer moves to the top right of the screen, and pretty well stays there...

I mean... if you play with the mouse, scroll the scroll wheel, etc... you can get the pointer to jump to to the left a bit, but it goes back to the top right soon after.

Initially, I thought...maybe it's not auto detecting the computer 100% correctly, so I moved the Micromys V5 jumpers to the 'Amiga' position

Based on information found here -> http://wiki.icomp.de/wiki/Micromys_V5

But that didn't solve the issue..

Then I thought...maybe the mouse connector (DB9) on the motherboard was worn or damaged, I got lazy and just swapped the A500 motherboard.

But that didn't solve the issue.

Sometimes, I can just unplug the Micromys V5 and plug it back in and the issue goes away

But that's not a solution

When the Micromys V5 'works' at startup, it stays working fine, I've not seen any issue appear after starting up successfully..

If I unplug the Micromys V5 when its malfunctioning at start-up and plug in an original Amiga mouse, the pointer works properly.

I don't experience any weirdness using the original mouse...ever...

Any thoughts on why I'm seeing this odd Micromys V5 behaviour ?

Quote from Jens

Please pardon the question, but what's the point of a socket? It will only lift the CPU high enough for the trapdoor to not close properly, and it'll keep you from adding a small cooler because of the added height.

Nothing wrong with asking questions, nothing to be pardoned.
Like many of these boards, this one will not going in an A1200, I have no immediate physical space restrictions.
The ACA500+ will be the 'host' system in my case, as I'm sure will many others.

Socketing the CPU from early on makes the card more serviceable here in North America where the iComp warrantee is of greatly reduced value given the cost of return shipping. If I had to return an iComp product under warrantee, I'd likely just use my credit cards extended purchase protection and later its two year warrantee extension in order to bypass all the shipping expense and simply get a refund for my bad luck.

Sadly, based on your response, all the cards must already have been populated, because there is no longer the more cost effective option of sending a socket in place of an MCU to the contract manufacturer. Meaning that a socket results in a re-and-re and a potentially damaged board.
So no reasonable way for iComp to make a little little more margin, and no reasonable way for me to pay for a little more serviceable card.

sad, but life goes on.

Quote from Jens

All CPUs are soldered to the board. The cost of adding a socket is too high.

Can this be a cost added option?
Like for an additional $50 you offer the card with the CPU socketed on the 50MHz model ?

Quote from JohanSSID

The Checkmate case is for me a disaster.

Not as a confrontational challenge, but, could you please elaborate on the 'disastrous' elements ?

For sure Jens dislikes that it might encourage SFX form-factor (ATX) PSU's,

and the unbuffered Zorro II option board..

That sorta gets wrapped in his cloak of "nothing good to say"

From your disaster comment, I am 'feeling' from the 'tone & vibe' that you don't like the styling,

but this is a purely written medium, so I'm likely missing 90% of what you are 'really' meaning to say.

I guess in your use of the word, I'm asking for a little description of the extent of the carnage ?

Be 'graphic' some of us are into that sorta thing you know..

I like the A1200 cases and hope to see new A500 cases but every time I've open my wallet to buy...they have been unavailable.

Which to me means they don't exist, despite any evidence to the contrary.

Not much point 'believing' in something, when you are perpetually excluded from it.

It doesn't matter how many pictures people take of the Yeti, I'll never know his warm embrace

Starting to feel like this about C64c cases too, but I think the guy working on it will fix this soon...not naming any names

I hold less hope for the new C64 keycaps...

In my opinion...A500 or A1200 really seems to depend on which side of the pond you live on...

Here in Canada A1200's are quite a bit more rare...and crazy expensive.

So.. it's just going to be the situation that A500's will get chopped, lowered, slammed, tuned and blown-out,

which means that at some point you need a bigger box to carry all your pieces

They're just not gonna fit in the stock A500 case anymore.

I'll use my own A500 to illustrate.

The base A500 was $200 CDN, then I added ACE2b, Indivision ECS V2, ACA500plus, ZZ9000, Lyra 3, Micromys v5, Zorro II riser, Checkmate 1500 case, and waiting on Jens to let us buy his ACA1234-50.

Finished price $2675 CDN which is about the price of a stock, booting, A3000 around these parts
How in the world do I shoe-horn all that into a stock case ?

Don't say 'you don't', because I'm clearly trying to keep Jens in business here

Also, it's an 'American' past-time to 'hot-rod' things...never give us your car keys...

Europeans, I feel, have it a bit easier because their circumstances mean that they get to start with an A1200 which is not as needy a machine.

So perhaps, in the end, they don't 'need' the bigger box. The proverbial 'bucket' of fried chicken.

We're clearly beyond the scope of why I opened this thread,

but I think it's been really positive, and I'd love to know more your thoughts on the Checkmate 1500 'disaster', before we all wander off.

Quote from Jens

I don't have much good to say about the Checkmate case

- the paint looks 'pretty'

- it's made of mostly metal

- it's not 35 year old crumbling plastic

- it comes in black, so it doesn't clash with the night

- you can put your keyboard under it
- you can park your monitor on it

There's lots of good things to say... I'm just not sure they outweigh the bad..

But I'm gonna find out

It's just money

Quote from Jens

Really? Reminded me of Douglas Adams (His books were actually the reason why I was kicked out of class room some 35 years ago; I couldn't stop laughing).

Ohh.. you're right of course .. Hitchhikers Guide.. Douglas Adams.. not Python..

I hate to bring up the uncomfortable bit, but..

We're 'operating' 35 year old computers, that were design intent to operate for maybe 5 years, 10 at the outer limit.

All of them, and us, are out of spec...

I mean..I can't speak for you, but I look nothing like I did in my teens, I'm definitely 'out of spec' but still functioning, however glitchy, all within an acceptable range. Just like my Amiga

In spec, out of spec, it's all rather dubious, an artificial construct really, to help one man limit his obligations to another.

Certainly nothing to get excited about... as we are not using our Amiga's to fly to Mars... well I'm not...

I'm not asking for ACA500plus support, so I'm rather surprised were onto an in vs. out of spec. discussion.

Though I guess that's fair warning to the next fella.

"If you climb that tree, fall down and break both your legs, don't come running to me." ~ Jens

Quote from Jens

Those Checkmate boards were supposed to be fixed

I don't think they were 'fixed', they just made a new batch, with different routing, that 'appears' to work.

Certainly that doesn't fix the first ones they made

And I hope the new ones, like I have, are 'fixed', but being I am an engineer, I would have appreciated some basic information from them on what exactly was wrong, how they fixed it, and a basic turn it on, turn it off demonstration of the defect and the fix.

We got nothing like that of course ...

So, I turn on my carefully calibrated GDDR6, LPDDR5, DDR, laying out eyes, and what do I see ?

All the signal traces on one side of a two layer PCB, a ground pour on the other side, and in the first revision, they split the ground pour with a trace for the ATX PWR-Good signal. So everyone of those 8MHz system signals is going to have delay and reflection.

Then I see the new version of the PCB and they moved that trace out of the ground pour and around the outside.

Quote from Jens

didn't the vendor intend to describe what you need to do in order to make it "all work"? Last thing I heard was "I need to formalize this before it gets published".

"Intend" no idea...

Mind reading is not on my resume, but if he ever did explain how it was supposed to 'all work', I must have slept in that day.

If you ever stumble over the 'published' explanation, please feel free to post it, though I rather suspect it's in the bottom of a drawer, in a filing cabinet, in the mens lavatory with a sign on the door that reads 'beware of tiger', in the basement, with the lights out and the stair case removed. (Python)

I could be wrong, but I think the fix is, give me 65 pounds sterling plus shipping and it will work 'this' time, I promise.

Quote from Jens

I can't recommend using Zorro stuff in conjunction with the ACA500plus at all. The ACA500plus is developed for direct connection to the A500 main board ONLY.

If I fall down and break both my legs, I won't be running, I promise...

But when this works, it really is great fun and I wish you could come along and play with us.

Because Jens, you are a toy maker, you make wonderful toys, but that's what all this is...just toys...for having fun...

And I'm gonna put an ACA1234-50 and a ZZ9000 into my 'not recommended', "out of spec", "powered by a monkey with a dynamo", Checkmate 1500 case. And really ... that should just make you smile

Have a great day,

My A500 Zorro II board is working fine with the ACA500plus.

I have not got my ZZ9000 yet, so I can't comment on bugs,

although, the MNT Research (ZZ9000) people do have one, and test on it, and report it works fine on their forum.

If you search for the Checkmate 1500 case project, you will see that you can buy the little Zorro II board, without the case.

Rob Cranley also made "Z-500" boards that are a horizontal version.

**Pro tip**, do not buy the Checkmate Zorro II boards used...

The first ones are buggy...and I saw that they ran a trace right through the ground plane layer, which likely caused a load of signal reflections.

The new version, which I've bought, moved the traces that bisected the ground plane around the perimeter, so likely the signal integrity is much better now.

There could have been other issues too...it's not like anyone really stepped forward, admitted a design fault, described it, turned it on and off, and published a fix. It was just one of those "Hey Yall, the new ones not broken" kinda deals.

What would be super fun...is to use the open sourced 'Bluster', which is a re-creation of the A2000 Buster Chip,

and modify the single slot Zorro II board, so it could have TWO Zorro II slots.

If only someone had the technical skills required
It's honestly more a limited market thing ... I suspect...

Though that cute little single slot Zorro II board costs $230 CDN delivered,

so there sure is plenty of profit per piece, if 'someone' was to make a two slot Zorro II version

<wink> <wink>

There is a cute little board that plugs into the A500's side expansion.
It replicates the A500's side expansion, in which I have an ACA500plus and provides a Zorro II slot for the ZZ9000
And as soon as iComp opens purchasing for the ACA1234-50, I'm buying one to plug into the ACA500plus.

Same board also has ACE2b, Indivision ECS V2 and Lyra 3