v2 Analog - Apple ][ VGA adapter build

[PhilC]

@rubber_jonnie when hand soldering caps and resistors I’ve found it’s easy to miss soldering one side properly, they look soldered but aren’t.

[rubber_jonnie]

@rubber_jonnie when hand soldering caps and resistors I’ve found it’s easy to miss soldering one side properly, they look soldered but aren’t.

Aside from all the checks I've already done, I have double checked under a microscope and they are all definitely soldered.

I did find 2 missing caps, guessing they got knocked off, but I did replace them. I even changed the diode on board 1 so it was the same as board 2. Now wondering if my RPi on board 1 has an issue.

It is weird though as the v2 works just fine in VGA or Z80 mode, just not with the MB in either.

[rubber_jonnie]

And the Mockingboard problem?

Turned out to be a bad level shifter, the 2nd one from the front of the card, the front being the VGA connector. Luckily I bought 10 to begin with, so I had 2 spare. Now I have one spare!!

Here's the machine:

PXL_20230429_140849037.jpg (362.71 KiB) Viewed 1558 times

From left to right, we have:

Slot 4 - v2 Analog in Applicard mode, so Z80 emulation in the RPi and able to run CP/M.
Slot 5 - v2 Analog in VGA mode sending crisp clear VGA to one of my displays
Slot 6 - The obligatory FDD interface.
Slot 7 - Mockingboard stereo sound card.

And in the Aux slot my RAM2E 64KB-8MB RAM card.

Next I want to look for other useful add ons, like a serial card and parallel card.

Very happy to have this machine back in GWO again, I really like it as a machine and a flashback to my computer studies days at school.

[HomeLate]

PCB's from JLPCB arrived and the parts from Digikey too. I'm half way through soldering one. Tomorrow I'll finish soldering and I'm only waiting for a PLCC20-20-dip adapter to program the PLD.

The 0402 are so small. I lost a few caps while sneezing

Which PLD did you plump for in the end? I used PAL61V8's directly soldered and both of mine work just fine.

As for the 0402 caps, well and resistors too, I'm sure I lost as many as I soldered...

Thank god for my microscope is all I can say.

I'm using the ATF16V8C PLD's which program fine with a TL866II programmer and work fine.

But I'm a bit confused which firmware to use: LC, GS of Wifi? I'm using regular PICO's with no Wifi.

[rubber_jonnie]

Which PLD did you plump for in the end? I used PAL61V8's directly soldered and both of mine work just fine.

As for the 0402 caps, well and resistors too, I'm sure I lost as many as I soldered...

Thank god for my microscope is all I can say.

I'm using the ATF16V8C PLD's which program fine with a TL866II programmer and work fine.

But I'm a bit confused which firmware to use: LC, GS of Wifi? I'm using regular PICO's with no Wifi.

If you have a standard Pico with no WiFi, use the 4ns firmware for LC for either Applicard or VGA. The 8ns LC firmware also works, but is a bit slower. AFAIK, if you use the WiFi firmware with LC boards it gets a bit crashy.

[HomeLate]

I'm using the ATF16V8C PLD's which program fine with a TL866II programmer and work fine.

But I'm a bit confused which firmware to use: LC, GS of Wifi? I'm using regular PICO's with no Wifi.

If you have a standard Pico with no WiFi, use the 4ns firmware for LC for either Applicard or VGA. The 8ns LC firmware also works, but is a bit slower. AFAIK, if you use the WiFi firmware with LC boards it gets a bit crashy.

Thanks @rubber_jonnie !

[rubber_jonnie]

Thanks @rubber_jonnie !

No worries, be good to see another up and running.

[PhilC]

And we got this far

IMG_2679.jpeg (323.37 KiB) Viewed 1407 times

I have respect for anyone who can solder these 0402 components, they are a real pain.

It’s going into the ultrasonic cleaner in the morning and then we shall see if it works when I get a mo.

If I had to make another I’d fork the git and redo it with bigger components so they are easier to build.

[rubber_jonnie]

And we got this far


IMG_2679.jpeg


I have respect for anyone who can solder these 0402 components, they are a real pain.

It’s going into the ultrasonic cleaner in the morning and then we shall see if it works when I get a mo.

If I had to make another I’d fork the git and redo it with bigger components so they are easier to build.

Yep, the 0402s are terrible, but I reckon I could build one from scratch in 2 hours now I have figured out some techniques. One thing I would say is check the level shifter pins very closely, I had some that weren't soldered, and it is super easy to miss bridges on the tiny pins. I used some ultrafine tweezers to push each pin to be sure they were soldered securely before using my multimeter to check for shorts between pins. Be aware SOME are supposed to be connected together.

I did consider the ultrasonic cleaner, but I used a slightly different method and jetwashed mine with IPA from an airbrush

You could try out the Z80 firmware to see if it works before soldering the 15 pin din on as that mode doesn't do video out.

Also, don't forget to use the preloader firmware before the VGA or Z80 firmware.

[PhilC]

Thanks for the tips @rubber_jonnie, I’ll get it done later hopefully.