Voltage regulation issue / 3.3v on Apple II VGA Card (Briel version)

I ordered some Palaveev version PCBs from JLCPCB.  It will probably be a while before they get here though, I used the cheapest shipping instead of DHL since it was about $15 less that way.

I still have some 74LVC245 from Juried left and I can order some more.  I think I still have plenty of ATF22V10 too.  I'll have to order a few more D sub 15 connectors and RPi Picos from DigiKey.

I'm interested in seeing how well the 80 column card emulation works.

Looking at the schematics for all these projects has been giving me some ideas.

I just finished building up 4 of these cards (the Apple II VGA Briel Version) and they work fantastic!

But I must ask;  Might there be a way the Briel Version card could also serve as an 80 column card for the Apple ][ (plain and Plus) if it were installed into Slot 3? (as example)

It looks like everything might be there to do it. [?]   This card would be even more valuable if it could serve as a 40/ 80 column card with VGA interfacing. 

I see others have made this inquiry as well within this thread.

I personally don't have the programming skill to pull this off, but maybe someone here does?

You could possibly have an option to change fonts as well.

Just thinking out loud...

macnoyd wrote:

...

But I must ask;  Might there be a way the Briel Version card could also serve as an 80 column card for the Apple ][ (plain and Plus) if it were installed into Slot 3? (as example)

...

Not possible for Apple II/Apple II+, since it doesn't have the extra hardware. You will need the Palaveev or the A2 Analog version for that.

More here: https://www.applefritter.com/comment/104440#comment-104440

I think the Palaveev v1.2 is the most interesting of this family of cards.

Modnarmai wrote:

I think the Palaveev v1.2 is the most interesting of this family of cards.

Damnit!  I just received PCBs for the 1.1 version from JLCPCB...  Now I'm thinking of binning them and ordering 1.2 boards instead...

CVT wrote:

macnoyd wrote:

...

But I must ask;  Might there be a way the Briel Version card could also serve as an 80 column card for the Apple ][ (plain and Plus) if it were installed into Slot 3? (as example)

...

 

Not possible for Apple II/Apple II+, since it doesn't have the extra hardware. You will need the Palaveev or the A2 A

I think you are correct.  It is the PLD that makes the extra functionality possible I am guessing.

I was interested too, got the boards today.

IMG_20231121_181045.jpg

Nice!

I recently encountered yet another variant of VGA -> HDMI adapter.

vga2hdmi-new_variant.jpeg

Outward most obvious difference is this one uses a USB Mini instead of USB Micro for power like most of the others.  Mod is obvious, very short wire from pin 9 of Dsub15 to pin on regulator.  Basically same as others just slightly different part positioning.

I bought these pretty purple Pico clones off Aliexpress because I thought they'd match the nice purple boards I got from Skate...  well, they match pretty well color wise, but unfortunately they appear to have a slightly different pinout and don't seem to work in the card...  Alas.  I will have to use them for someting else.  It appears they have fewer GND pins and more GPIO, so they may be just what I need for the "Pico Transporter" project I'm contemplating.  That would allow me to put two Picos on a board and use a pin off the one doing the VGA out from the A2 to switch the output between the A2 and the 2nd Pico which would be running Pico-XT.  If it has a couple more pins it could probably even do the keyboard/mouse/joystick mapping from the A2 to the PC side, especially since it wouldn't need to continue to run the A2 vifdeo out when that side's VGA output was active.

Other differences between these is they have a 4 pin interface at the rear of the board instead of 3 like the offical RPi ones, and they have a USB-C connector instead of Micro USB.

rpipicoclone.jpeg

These are exactly the ones I was talking about here: https://www.applefritter.com/comment/105650#comment-105650

CVT wrote:

These are exactly the ones I was talking about here: https://www.applefritter.com/comment/105650#comment-105650

Yes, it does look like the same board.  It appears that this one would require some minor tweaking to be used in the existing A2VGA cards, but it might be, as I said, perfect for what I need if I do the "Pico Transporter" since it has a couple more pins available.  Between that and maybe some unused space in the 22V10 there might be just enough to make things work without having to add a lot more components.

I''m kind of wondering how necessary that other project is since you're getting to a significant portion of the functionality with your ESP32 Softcard.  The only thing mine would have really different is the direct VGA output and switching between A2 video and Pico-XT video over VGA instead of NTSC or PAL composite.  I don't know how big of a sales point that would be.  I am also not sure how feasible the Pico-XT is.  I am waiting on one more part to try to get a Murmulator and Pico-XT going and then I can find out.

One other thing I hope to determine when playing with the Pico-XT and Murmulator is whether it's direct HDMI output option works and how well.  I think it may be possible to make a version of the Ralle Pa or Briel card that does direct HDMI out instead of VGA and eliminate the need for a VGA->HDMI converter entirely.

One thing about that too, is that I think that the "Pico Transporter" would be simplified if it was all HDMI instead of VGA.

It's hard to talk about an XT emulator before seeing how fast it runs on the Pico and how much has been implemented in terms of graphics modes and sound.

However one thing I am pretty sure will be a success is the HDMI version of these VGA cards, even if it's based on Vince Briel's version, because for every Apple II+ that is still out there today, there are 10 Apple IIe's. Everyone has an HDMI monitor at home and with a jumper to toggle the scanline emulation it will be a killer expansion card. Besides, except for the original project, most of these VGA cards still don't have a solution for what started this whole HDMI conversion in the first place: how the hell are you supposed to get the monitor’s VGA connector inside the Apple IIe and close the lid??

If you find the right HDMI cables you can BARELY fit them through the D-shell openings in the back of a //e.  VGA connector?  Not a chance, so you have to use an extension like the one skate mentions.  Getting rid of the VGA->HDMI converter and outputting HDMI directly would not only reduce the cost of the setup it would be one less thing to deal with, make sure is plugged in securely, etc., and that much more open room inside the machine when you are working in there.  If it can be made to work I think it will be a win.  Even for people who need a VGA connector for their monitor, there are converters that go the opposite way, from HDMI->VGA, and those don't need power either, so its an easier thing.

Yeah, it is a little premature to talk about Pico-XT until I can actually test how well it works.  It may be not worth it.  However, I still like some parts of the "Pico Transporter" idea.  Since the ESP32 is at least in theory faster than the Pico, a possibility is to combine A2VGA through a Pico with the XT emulator running on an ESP32 on the same card and the Pico would be able to switch the HDMI or maybe VGA video between the two.  Your work with the ESP32 Softcard is already proving that you can do the emulation at acceptable speed, the main advantage of what I am talking about would be getting around the limitations of composite NTSC and PAL video.  You've already done most of the rest of the work.

skate323k137 wrote:

softwarejanitor wrote:

If you find the right HDMI cables you can BARELY fit them through the D-shell openings in the back of a //e.  VGA connector?  Not a chance, so you have to use an extension like the one skate mentions.  Getting rid of the VGA->HDMI converter and outputting HDMI directly would not only reduce the cost of the setup it would be on

I can see your point.  But the NTSC and PAL composite output from an Appple II is notoriously poor, so even using cheap VDA->HDMI or HDMI->VGA devices isn't really that big of a deal in my opinion.  It's low resolution and low frame rate and limited color pallate.  And this is all hobby level stuff, not professional work.  High end devices may be overkill for the expectations of most of us.  The Briel and Ralle Palaveev cards through the cheapest VGA->HDMI and HDMI cables to a cheap Benq monitor produce way better quality video than the BMC composite color monitor I used back in the day.  Hands down better.

So a new "mini" variation has been developed of this card, not yet for sale or open sourced from what I can tell.  It's SMD, so not as easily accessible for people like me who lack SMD tools and experience if sold as a kit.  He implies he did something with noise filtering to make the colors more vibrant.  Not exactly sure what.

https://mstdn.jp/@KayKoba/111642520428137345

And I see the original author put out new firmware about 2-3 weeks ago with the following in the changelog:

Support text character set modifications by @markadev in #24

Improve reset detection by @markadev in #25

Thanks for updating and compiling the default scan line version!

The mini version I mentioned in one of my last posts is now available and on GitHub:

Mini VGA Github

Looks like the Briel version, it just runs Marks firmware. Which was updated to 1.2 a week or so ago.  

Edit: I guess for now some assembled ones are available in limited quantities, more coming soon:

https://en.infinityproducts.co.jp/product-page/a-vga-mini-card

nick3092 wrote:

The mini version I mentioned in one of my last posts is now available and on GitHub:

 

Mini VGA Github

 

 

Looks like the Briel version, it just run

That one uses SMD devices that aren't nearly as easy for most hobbiests to assemble as the Briel version.

In post #175, 'softwarejanitor' wrote:

" That one uses SMD devices that aren't nearly as easy for most hobbiests to assemble as the Briel version. "

Uncle Bernie comments:

While my opinion about SMD technology is that it most likely was one of the major factors in killing off the electronics kit hobby, hobbyists should not despair. I've taken a look at the assembled PCB at:

https://en.infinityproducts.co.jp/product-page/a-vga-mini-card

And as far as I can tell from the photos, none of the SMDs on the motherboard are of the smaller pin pitch and neither the "dust"  types which are known to be impossible to solder by hand. The little daughter card could not be hand soldered  - they sell them completely built for a reason.

So don't despair, even I could solder these SMDs in, and I'm probably much older than most of you.

The trick is to apply a small solder blob to one - and only one - SMD pad per SMD component on the PCB. Not too much solder, just right, see here:

SMD_Step1.jpg

(This photo is from the latest generation of my Gen2 improved ACI card for the Apple-1, ignore the red ring, that is excess solder mask).

Then grab the SMD with tweezers and 'slide' its corresponding solder pad into that blob, while heating the blob with a fine tipped soldering iron (I still use the big 60W Weller WTCP-S for that, but with the finest tip they have). For QFN or TQFP packages, use an end-of-row pin you can reach with the tip at the associated corner of the IC package, so it can only touch that pin, and no other pin. Result:

SMD_Step2.jpg

Then you can solder all the SMD pins which have seen no solder yet. And then re-solder the first pin that was the starter - because if you don't do that, it most likely is only a poor solder joint, as the part was only shoved into the solder blob, with no flux core solder wire involved.  Result:

SMD_Step3.jpg

Even at my age I can hand solder TQFP packages down to a 0.8mm pin pitch:

PDRM4539.JPG

But that's about the limit I can do. Any smaller / finer pitch (like 0.5mm or smaller) would require a professional SMD rework / repair station with a hot plate and all the solder pastes, the glue and reflow soldering iron (typically, based on hot air). The SMD station in the company I worked for did cost a few thousand dollars and the ladies there were very skilled and could do even the finest pitch packages, including BGA.

Beware: I have no experience with the cheaper Chinese made "tools" sold for SMD. And I don't want to make that experience ! Most Chinese made tools and instruments I ever encountered are low quality cr@p / incompetent knockoffs of the real deal - which, being the originals, are much more expensive. But with bad tools and bad instruments even a master craftsman / professional can't do good work ! Buyer beware !

- Uncle Bernie

softwarejanitor wrote:

...

That one uses SMD devices that aren't nearly as easy for most hobbiests to assemble as the Briel version.

For this card the advantage of using SMD chips is only if you are selling fully assembled and tested cards. You can have the cards populated by the PCB maker very cheap.

However for a hobbyist who wants to make it himself it’s terrible, but not because SMD soldering is hard, but because the chips are not socketed. If one of them is bad, it’s a nightmare to swap. You cannot use them in another card, you cannot try the card with different chips, or experiment with different series, like we did with HCT, etc.

On top of that if DigiKey sends you the wrong resistors (like it happened) no one will be able to spot that from the pictures.

In post #177, CVT wrote:

" On top of that if DigiKey sends you the wrong resistors ..."

Uncle Bernie comments:

This is why every user of SMDs should have a "MS8910 Smart SMD Tester":

https://www.ebay.com/itm/184068953691

They are reasonable cheap and amazingly accurate for the price. The mine needed a new CR2032 battery after 10 years or so.

I check every SMD with it before I solder it in. While 0805 resistors usually have small numbers on them telling the resistance, SMD capacitors do not give you any clue. So you absolutely need one of these MS8910.

- Uncle Bernie

UncleBernie wrote:

...

So you absolutely need one of these MS8910.

There are also SMD probes for regular multimeters, a.k.a. tweezers: https://www.aliexpress.com/item/1005006172969626.html

In post #179, CVT wrote:

" There are also SMD probes for regular multimeters ..."

Uncle Bernie warns:

Unless there are electronics in that probe (which I doubt for the $1 price point) this thing will be useless for smaller capacitors in the 10-100pF range and it will be useless for smaller inductors, too. What it certainly can measure is resistors, but as I have mentioned in my post #178, down to size 0805 the SMD resistors typically have small numbers on them which tell the resistance. And anything smaller than 0805 does not qualify as "bird feed" size but "ground pepper" size. The next size ist "dust" size. Hobbyists better avoid the latter two SMD sizes.

- Uncle Bernie

UncleBernie wrote:

Unless there are electronics in that probe (which I doubt for the $1 price point) this thing will be useless for smaller capacitors in the 10-100pF range...

They don't have any electronics, but they are perfectly fine for small capacitors. I can measure a 10pF capacitor with my regular multimeter and factory probes and detect one as small as 1.5pF, except that it shows it as 2pF. The multimeter is nothing special - just a 10-year old UNI-T UT61E with a REL button to subtract the capacitance in the leads. Of course it's very hard to grip it with the regular circular tip probes and half of the time it ends up flying away never to be found again, which is why the tweezers are useful.