Just saw it and it was awesome 😁

If you are going to build that even smaller one, let me do a suggestion for the name:

ToyLet or ToyLed

Whatever suits best 🤣

rasteri wrote on 2021-08-05, 08:11:

Mu0n wrote on 2021-08-03, 13:55:

Edit2: after reseating the SOM for a couple of times, I get a bright blue led again, but the voltage goes between 4.40 and 4.80 (jumps around periodically), even under minimal load (no ps2 peripherals, no vga, no network, etc)

Does the SOM work in your other board? Just trying to narrow it down between the SOM and the rest of the board.

Also voltage dropping to 4.4 often means the USB cable or charger isn't strong enough, I often have to experiment to find a combination of cable and charger that works 100%

Yup, I made some tests after that post.

Let's call them:
board #1 (known working with and without load)
SOM1 which was on board #1
board #2 (board with voltage issues)
SOM2 which was on board #2

I no longer get a 4.40 V on board #2, it's back to the much lower 2.40 ish V now.

test 1) board #2 outputs stable 5.0 V when SOM2 is removed

test 2) SOM2 put on board #1 works flawlessly so it isn't at fault (so far)

test 3) I thought I saw imperfect Vreg leads on board #2, especially on the small left lead (GND). I had the impression the top of the leg wouldn't cleanly be contiguously reach the - side of the capacitor near it, so I added flux and solder to them - no change though

test 4) when it's been a *long* time since I powered the unit, the capacitors must tend towards less charge and the behavior when powering the unit gives me about 1 to 2 seconds of solid blue led on the SOM on board2, then it reverts to low voltage (around 2.40 V, not enough to make the blue led shine bright, it's subdued).

test 5) when I power it off, then on again after a short time, the solid blue led lasts for way less than a second (I estimate about 100-200 ms tops) before going to subdued blue.

test 6) the cable powers board #1 with either SOM1 or SOM2 like a champ. I also, for good measure, tried another charger, other sockets, from a PC tower, on a power bar or not, etc. Doesn't make a lick of difference for board #2.

edit - gave a more accurate value up (corrected in bold) below when faulty.

Uh.....waitaminute

the voltage regulator is trying to ouput 3.3V, that's by design from day 1, I'm assuming. Is your power adapter bringing in 5V or 3.3V? If it'S 5V, do they run particularly hot? Mine is 5V and various values between 1.2 A and 2A.

more accurate measurements: 4.92 V without som2 right after the fuse compared to GND (power connector's casing). Same goes between pins 1 and 3 of the VREG.
with som2: both around 2.40 V.

Yeah the VREG is a 3.3v one, it powers the SD card and the pullups on the ethernet port. If it was broken the SoM would still likely work.

I would say triple-check the soldering on your SoM headers, perhaps when the SoM is connected it's causing a short because of a mis-soldered pin.

BTW update video here with some network games & wavetable stuff - https://www.youtube.com/watch?v=2P1E2vjpcRo

I've done a single-check so far. I don't remember if I did a thorough continuity pin by pin, and adjacent pairs per pair on this one (deffo did on board 1) but whatever the problem is, it has to satisfactorily explain 2 things:

1) this machine has worked for a month until I did some tests with a powered vga+audio to hdmi on my TV (the other machine performed well).
2) it gets proper power for an interval of time before it lowers back; isn't that that indicative of a capacitor that can't hold its normal value of charge, tries to rise to it before a short happens? No idea if that is a regular failure behavior. They don't teach these things in college theoretical physics classes.

Hello there. I saw your builds for the original and the smaller version about a week ago. They were a very nice watch. Very cool project you did there. 😁

Mu0n wrote on 2021-08-05, 22:44:

2) it gets proper power for an interval of time before it lowers back; isn't that that indicative of a capacitor that can't hold its normal value of charge, tries to rise to it before a short happens? No idea if that is a regular failure behavior. They don't teach these things in college theoretical physics classes.

Oh... that could be the polyfuse (F1) then. I possibly under-rated it.

In fact yeah, it looks like the hold current of the one I used in my prototypes is 750mA, I've measured the 86DX as drawing as much as 900mA under load so it's possibly tripping the polyfuse.

Try replacing F1 with a dead short (i.e. bridge the pads with solder). See if that fixes it.

The polyfuse isn't really neccesary, so leaving it as a short probably won't cause issues, but next time you're ordering components from mouser you could replace it with a 1A polyfuse (e.g. 0603L100SLYR is the one I specified in the final BOM)

Oh man, is it possible it could also explain why I've had the hardest, unreliable time running Second Reality under various conditions? After finally determining it needs something like 2mb of expanded memory for SB output and not the maximal amount this machine has (or it just hangs), it now just boots on machine 1.

edit - that did the trick.
Massive thanks, I really appreciate you and others in this thread to take the time at helping me get back after I stumble multiple times.

I'm on my 2nd set of MicroSD card readers for both machines and these things gave me about 20 ejection cycles on average before they cease to hold the card in and just auto ejects, as the metal pin can't stay put in a plastic groove surrounded by the lowest plastic walls that get scratched away, letting the pin escape. Of course, you can lift the top half of the casing, remove the spring and pin and transform the reader to a friction based one, but doing so destroys some structural elements that tie both halves together. I don't feel like ordering a 3rd set for this one machine so, I'm going full desperate mode and hoping silicon grey will cure and hold things enough. Not a pretty solution but I don't care much about that!

Edit: if I had the inclination to improve the fabrication of further units, it'd be to manufacture thinner pcbs for the front and back pannel - I'd attempt one tick lower if possible, since the thickness prevents easy insertion and ejection of the MicroSD with your fingers. I've scotch taped a small tab on one of my cards and it helps tremendously apply just enough force indirectly to eject it. That, or just straight up a bigger hole allowing your nails to get in there.

BIOS battery progress:

I boneheadedly bought CR2032 because it seemed swell on the mAh front, but I completely forgot to check for space much. The cell holders I got are neat but way too thick for the job.

So, I extracted the pins, flattened them and it passes the fitting test, if I put it on the underside and pass my cables through the nearest structural hole on the important corner of the SOM.

There's more space above the SOM, but that area gets lukewarm-hot and it would definitely have to be above it and it would hamper its removing/replacement/reseating, so I'm more comfy putting the battery underneath.

edit - DOUBLE CHECKING is important! I was aiming at the wrong corner. The wire lengths are similar though, and I haven't soldered past the point of no return yet.....(images are fixed below)

@rasteri did you ever find a supplier for the CS4237B-JQ ICs other than UTSource? They've gone inquiry-only there and you know how much of a black hole that can be...

Seriously tempted to buy an ISA card with what look to be pin-compatible equivalents and desolder that!

H

Heathen wrote on 2021-08-27, 08:17:

@rasteri did you ever find a supplier for the CS4237B-JQ ICs other than UTSource? They've gone inquiry-only there and you know how much of a black hole that can be...

Seriously tempted to buy an ISA card with what look to be pin-compatible equivalents and desolder that!

H

where are you located? I can part with a chip 😁

keropi wrote on 2021-08-27, 08:40:

Heathen wrote on 2021-08-27, 08:17:

@rasteri did you ever find a supplier for the CS4237B-JQ ICs other than UTSource? They've gone inquiry-only there and you know how much of a black hole that can be...

Seriously tempted to buy an ISA card with what look to be pin-compatible equivalents and desolder that!

H

where are you located? I can part with a chip 😁

That's very kind of you, I'm over in the UK (albeit somewhat further south than rasteri!)

G

Heathen wrote on 2021-08-27, 09:13:

That's very kind of you, I'm over in the UK (albeit somewhat further south than rasteri!)
G

I will send you a PM with my email so you can send me your details

The EM08C monitor recently reviewed by Adrian's Digital Basement makes for a great display that reacts well to every VGA res I threw at it. It makes for a great nightstand setup, or corner of a desk.

Mu0n wrote on 2021-08-27, 10:24:

The EM08C monitor recently reviewed by Adrian's Digital Basement makes for a great display that reacts well to every VGA res I t […]
Show full quote

The EM08C monitor recently reviewed by Adrian's Digital Basement makes for a great display that reacts well to every VGA res I threw at it. It makes for a great nightstand setup, or corner of a desk.

Nice! I've got one on order myself.

I wonder though how much my opinion is about the monitor and how much is nostalgia seeing Jazz Jackrabbit - my first ever demodisk game.

G

FYI:
i've found another(maybe already known) Vortex86 Board: https://www.embeddedarm.com/products/TS-4400
that uses coreboot+SeaBios (both open source) as Boot-System/Bios

I got Vortex86-6072.
I installed Win98se, but there is no video driver.
Can you advise me on the video driver of this board?

Who knows about Ultra-AGP™ VGA controller graphics cards?

A very long, long, time ago, I remember driverpacks being a thing. Maybe there is one in there good to go.
https://msfn.org/board/topic/98369-driver-pac … ows-959898seme/

shimart wrote on 2021-09-10, 07:25:

I got Vortex86-6072.
I installed Win98se, but there is no video driver.
Can you advise me on the video driver of this board?

The OG Vortex86 was based on an SiS system-on-chip - perhaps one of these drivers ? - https://www.philscomputerlab.com/sis-chipset-drivers.html