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How’s progress? JS

A "faux-tograph"! (snicker). Couldn't resist. Where there is a will, there is a way. Here, in the current environment, where there is a severe chip shortage, it is nearly impossible. Yet, if the market reaction to the shortage ends up being an over-reaction, resulting in an abundance of...

My thinking was that I don't want to destroy any of my good equipment on the first go-around - I really have no idea what is going to come out of these old chips. These little speakers are... disposable :D And they can hook right up to those outputs. If they survive, then I can assume it's...

@Stephanie-Wallace , do you think I can use these (or similar) with the audio shield? At least to get started? https://www.amazon.com/gp/product/B07FTB281F/

Good point. But, like you said, these pokeys are getting harder, and more expensive, to acquire. Although, it does seem like some in the Atari community are trying to develop pokey replacements, and the like. PokeyMAX (1, 2, and 3), PokeyONE, etc.

Sheesh - your project sounds amazing; makes mine seem lame 😜

Oy - tell me about it! I'm so nervous handling these things. Yeah, I looked at the NXP application notes a while ago, but I couldn't find the way to create the 6502-style parallel bus. The sample file that was supposed to be attached to the app note was absent :(

Pokey#2 Received and extracted!

Agreed. I never solder IC pins to boards. Never. Sockets or solderless breadboards. My second pokey is coming tomorrow - very excited to do this!

Great! That's what I was hoping you'd say; I will definitely use that to mix the two chips for stereo out. I'm now checking to see if I can acquire any more of these (assuming that the price is reasonable). I don't love the idea of having to pull the chips myself; they're soldered right into the...

Yeah, the schematic is very helpful - great find! And, yes, I do find myself using logic level converters often, because all the vintage/retro stuff has +5V logic. So, I have a handful of 8-bit shifters handy. I also happen to have 1.8432mhz oscillators, as I use those with my WDC65C51s. This...

That would be great!

Here’s a simple question, @Stephanie Wallace . Can I simply run Pin 37, audio out, from a pokey into one, or both, of the Line Ins on a Teensy Audio Shield? Would I need any resistors, or anything else, to connect that audio out to line-level inputs properly?

That's very cool (and thanks for sharing all that!). I got into retro electronics during COVID, revisiting the ins-and-outs of 70s, 80s, and 90s retrotech that I never really delved into in their day; for the most part, I was too young at the time, and I didn't have any access to the nuts and...

Yeah - I just shelled out for another one. Ya know, just in case. I like to have a back-up. You seem to be quite enamored with the YM2149. Any particular reason(s)?

Well, you seem to know a bit about this! Since I'm not reading a keyboard or potentiometers, is there a minimal setup I can use? What about the audio output (Pin 37)? Does that need to go to an amplifier? I would imagine I just need to connect the data and address lines, and not much else? Do I...

Thanks. Starting with the basics, is this something to be bit banged, or is something more elegant and precise required? What about clocks? I only have one, so I guess that precludes stereo?

I have a copy of Atari 7800 "Ballblazer," which contains a Pokey sound chip. If I desolder it from the board, is there any way to "use" it (for playing music) via a Teensy 4 or 4.1? I also have a teensy audio board (Rev.D) to use with it, if necessary. I thought it would be a fun project...

Oh, warnings. You'll always have a lot of those - yellow and orange. Just take note of the orange ones, but unless you get a red error, you're fine. The rule checks are just overly sensitive. Don't worry about the yellows and oranges, especially if you're just doing a tutorial.

@Frank B , Got a question for you - your mcu expertise... QuadSpi Flash! I read your code, as I installed 8mb psram and a flash chip on one of my Teensy 4.1s. The PSRAM passes the test. With the flash, it finds it and asks me if I want to format (y). I do so, and it again finds the flash. Then...

That's fine - the Artix 7 35T is a lot of board! The Arty version is the same chip as the Basys3, but it makes much more of the IO mobile and available. I'm guessing that drove your decision. Which specific tutorial are you trying? When Digilent uploads new ones, they often don't delete the old...

Absolutely - I have a few on my desk right now :D I'm hoping you got the A7-100T version. That is a fantastic piece of hardware, beginner or otherwise. Make sure you do the tutorials on the reference page you sent me; that will get you into the workflow. Once you do that, you'll see how you...

Well, being familiar with your other work, I'm sure you'll come up with something; you've got the creative spirit :D Maybe, just to learn, take something (simple) you would do with a MCU, and make it into a FPGA project. I mean, that board has seven-segment displays, switches, LEDs - start by...

Hey, @Frank B , how is everything going? Haven't heard from you for a while. J

Still working on it - all is well on the teensy side, though. I'm having issues on the FPGA side. I may take my own advice and switch to an Artix-7-based device :D Jon

Okay, now trying to get it up and running...

Happily - try this: https://digilent.com/shop/basys-3-artix-7-fpga-trainer-board-recommended-for-introductory-users/ Xilinx is my personal preference, and the Basys3 is a great board to learn on. It's a powerful enough starter board to be useful, and it will have you up and running in no time...

Absolutely! Any of those things are doable. I'm often surprised at the fact that many people who program mcus don't dabble more in programable logic (and the other way 'round). https://forum.pjrc.com/threads/68310-Idea-for-an-Arduino-Vidor-4000-Slayer!?highlight=vidor But, I digress ;) I can't...

Are you kidding? I was so excited about this that I desoldered my whole protoboard to expose the best multi-region, clock-capable pin! Fingers crossed! Jonathan

I can see it now. Seems the author of the library isn't quite sure how to approach this either: https://forum.pjrc.com/threads/62362-VGA-out-for-Teensy-4-0-4-1?p=295639&viewfull=1#post295639 Now I don't feel as foolish :confused:

I'd be happy to have your "limited knowledge" any day! I love your work. Anyway, building on what Frank says in his comments, might there just be a way to route your video pll5 clock (at 25.175 MHz) to SAI2 or SAI3 and out to a pin via i2s's mclk? As you've stated in other posts, the pll audio...

I can't open the link - it says: "Invalid Attachment specified. If you followed a valid link, please notify the administrator" Without a guide, this documentation is impenetrable. Denser than Microchip PIC documentation! (Yeah, I've tried my hand at that, too). Bleh!

Hey, @Jean-Marc - you should check out this conversation we've been having about your VGA library: https://forum.pjrc.com/threads/67668-Routing-pll5-to-an-output-pin-on-teensy-4-1?p=295632&viewfull=1#post295632 You're the best person to answer this. Would you consider adding DE and Pixel Clock...

Lol, shouldn't be a problem - going over all this with you, I'm kind of starting to get the hang of it. You're a good teacher! Jon I should say that as we've done this, step by step, I've been looking up the registers you've pointed me to, amongst the other things, to really understand this for...

That's funny! We must have posted at approximately the same exact time! Spooky! :p 25.175 MHz Oh, as an aside - do I need to modify the VGA library itself with this code, or can I just put it in the sketch?

Haven't been able to get it to work. First, there was a nascent, experimental audio driver tucked away at the end of the VGA file, which happened to use SAI1 and pin 23; so, that was why the first attempt had to fail. The pixel clock (25.175 MHz) is routed through the video pll 5. So, do I...

Nope - that doesn't work. The pixel clock is in the video pll - that's what has to be routed out; but I don't have the background to do it.

Wait... could it be as simple as this? #define PADCONFIG ((1 << 0) | (1 << 3) | (1 << 6)) // Select MCLK IOMUXC_GPR_GPR1 = (IOMUXC_GPR_GPR1 & ~(IOMUXC_GPR_GPR1_SAI1_MCLK1_SEL_MASK)) | (IOMUXC_GPR_GPR1_SAI1_MCLK_DIR | IOMUXC_GPR_GPR1_SAI1_MCLK1_SEL(0))...

So, for fast, I see, according to your notes: #define PADCONFIG ((1 << 0) | (1 << 3) | (1 << 6)) The other settings, regarding the CCM clock divider register: CCM_CS1CDR_SAI1_CLK_PRED(carrier.i2s_clk_pred - 1) CCM_CS1CDR_SAI1_CLK_PODF(carrier.i2s_clk_podf - 1); Any idea what the proper...

:cool: Much appreciated!

Frank, thank you! I will give it a shot - I see I can use pin 23, too, which would be optimal. I shall report back ;) Jon

Frank, Thanks for the fast reply! :) Yes, I did see that. But, like I implied, my "thing" is really FPGAs and hardware, not so much MCUs and embedded code - I'm just in a position where, sometimes, it is helpful to use them (particularly the Teensy). Stated differently, I'm kind of a "dummy"...

For those of us less technically inclined, how would we do this? Specifically, I'm routing all the VGA signals (from VGA_t4 by J-M Harvengt) to an FPGA to create an HDMI output. However, I need both a DE and Pixel Clock signal (from the Teensy 4.1 to the FPGA) to make it work. Could anyone...

Right on, @xxxajk!!! Did you post the code somewhere?

Well, @xxxajk , in that case, welcome back ;)

@PaulStoffregen I can track some down. One thing I did notice is that there seem to be plenty of the so-called "open source" FPGA ICs by Lattice Semiconductor (e.g., the "ICE" chips). The prices are really good, as well. The iCE40-UltraPlus 3K...

@PaulStoffregen Yes. Mouser, Jameco, Digikey, etc. The usual suspects.

@xxxajk , Funny, I was thinking of adding CP/M compatibility to one of my designs by adding a Z80 connected via a VIA 65c22 - two, actually, port-to-port. Are you a member here? http://forum.6502.org/

@xxxajk , @miciwan , @KurtE , and @Rezo : I was going to post this here: https://forum.pjrc.com/threads/68228-Ideas-on-a-T4-parallel-library-using-FlexIO But I think it would be a little off-topic and tangential. Anyway... When it comes to fast parallel I/O, or projects with MCUs that require...

Love It! @xxxajk That's beautiful!!!