Well just when I thought everything had been covered, and all the bugs had been safely put to bed (or wherever dead bugs go), another problem surfaced. It too was obviously something that had been in existence for quite sometime, but had somehow flown under the radar. What I'm talking about has to do with the stock Atari keyboard's CTRL, SHIFT, and BREAK keys becoming garbled. Or in other words erratic in nature.

I think the reason I didn't see this was that during the early days of TransKey development, when I more thoroughly tested under all possible criteria, this issue did not exist. But that was also before I configured the code for a sustained key press from the PS/2 keyboard side of things. Prior to doing that, I had only given PS/2 key presses a timed key press equivalent on the Atari key matrix, which at first appeared to work fine, but later I realized not under all circumstances (or with all software applications). So in a later iteration of the firmware I implemented a more Atari like key response, and had it maintain an Atari key down for as long as the PS/2 key equivalent was being held as well. This appeared to work fine at the time, but apparently I never went back and tested this with the actual Atari keyboard still connected. And it appears no one else has either, or they're just not complaining about the erratic keys on the stock Atari keyboard. Or better yet they probably don't use the stock keyboard since installing the TransKey.

So back to the problem. As best I can tell the issue was associated with the new code that was added for sustained key presses at the time, and has been around ever since. So once I realized this, it was a simple matter to look at the routine in the firmware and spot the offending line of code. It turned out to be the Pokey KR2 line handling that was the issue. This is where a held key was using a TTL based version of a PIC I/O line to communicate to the Pokey KR2 bit, irrelevant of what the mode was actually set to (float or TTL). Float is the case where one of the PIC's I/O ports mimics an open drain output, thus still allowing the Atari keyboard to work in parallel with the PS/2 keyboard. TTL mode was only suppose to get used when no internal Atari keyboard is connected, usually in the case of an XEGS, but also applies to a 1200XL. this mode can be toggled by pressing CTRL+ALT+X, with ALT+X showing the present setting (ON = TTL Mode, OFF = float).

So once the bug was discovered it was a very simple matter to correct the situation, thus restoring the stock keyboard to full functionality.

This has now been fixed in both the 'classic' version, and the new 'J' version firmware. Downloads are available HERE for the newest universal V2.7J version, and HERE for the 'classic' V2.6 version, which has now been depreciated where new hardware designs are concerned.

There's no need to update the TK-II firmware on an XEGS, or for the 1088 series machines. And there is also no need to do so even on other systems where you no longer use the stock Atari keyboard.

- Michael

Back in early 2019 I decided to incorporate the SIO2MIDI into a 600XL. And while I was at it, I also added UAV upgraded video (including the missing DIN-5 jack on NTSC systems), 64K RAM, and BASIC Rev C. It was a fun little project at the time

It languished for a while afterwards, but then I set it up in a permanent spot on my workbench, attached an SDrive-Max to it, and connected it to a tiny color TV I pulled out of storage. It then became my JOY2PIC programming station, and was quite useful in this new role.

However never one to leave well enough alone, and getting inspiration from Flashjazzcat's video on installing a U1MB inside a customer's 600XL, I started thinking why not take it a step further and also install an internal CF drive. But what could I use to make that happen? Then it hit me... make a new board mimicking the XEL-CF3 circuit, and piggyback Antic because virtually every signal needed was already there. So was born the XL-CF4.

It was going to be very tight space-wise in order to fit underneath the stock keyboard. So to help out, I shifted the piggybacked Antic towards the back. Then to get the ID44/CF Adapter to fit, I had to remove it's female header and solder it directly to the male header on the board. This was just enough to do the trick.

But of course I wasn't going to stop at only installing The U1MB and the internal CF drive, I also decided to add a TK-II as well, which actually made it much easier to test stuff without the stock keyboard getting in the way, or risk damaging its Mylar circuit connection from the constant plugging and unplugging that would have ensued.

Flashjazzcat's video gave me the best location and mounting method to use for the U1MB. And believe me when I say there really was no other choice.

Drilling the mounting holes was the trickiest part, which required slowly incrementing in size from a tiny drill bit to the final size. It's literally on the edge of the board threatening to break out at any moment. Check out Flashjazzcat's video above for the details on doing this.

There were a few other tricky parts such as making the hole for the CF card to pass thru. However because it sits just above the bottom of the case, only the top half of the case needed to be filed to accommodate the actual CF card passing through it.

I was able to mate up the top and bottom of the case, mark the left and right side of the required opening and then measured the thickness of the card to get a height (I added a smidge more to allow free travel). The end result looked pretty good.

The downward angle towards the right is part of the original case design, so there was no way other than Bondo or plastic fillers that could have been done about that. Although it looks kinda like it's talking :-)

Wow but where was I going to mount the PS/2 keyboard connector for the TK-II ?

I found a tiny bit of space between the joystick and the SIO jacks, but it required notching out the SIO jack mounting ear on that side, as well as doing an extreme reduction in the PS/2 jack interface board (lot's of sanding required). I also sanded off the bottom of the interface board to minimize the height of the various soldered pins.

Lastly I also had to move two resistors, and scrape off part of the ground plane on the 600XL motherboard, all to reduce the height at which the jack would be mounted off the motherboard, and thus prevent it from shorting out to the ground plane. A little epoxy completed the installation.

What's nice about having the TK-II, is the flexibility of putting the keyboard wherever I want irrespective of the computer. And secondly the TK-II has some hot keys aimed at supporting the  U1MB as well as the Loader. However I did discover a small timing issue with the TK-II firmware that required my attention (stay tuned for a new version to be released soon).

As for how the project turned out... I think the final results speak for themselves.

So what all is inside this Monster 600XL ?

• UAV
• SIO2MIDI
• 64K Base RAM Upgrade
• U1MB
• XL-CF4 Prototype
• TK-II-PBJ with ARROW2JOY Feature Connected to Joystick Port 1

What might I still add ?

• Internal Dream Blaster S2 MIDI Synthesizer with a 3.5 mm Stereo Jack and a Mini-Toggle Switch to Select the MIDI Source (Internal or External).

Will the XL-CF4 be Made Available to the Public ?

No I'm afraid not, or at least not in its present form. There are still some timing issues that need to be resolved, which limit it to only working reliably with a handful of clone Sandisk cards I have left over from a lot of 10 pieces purchased years ago on eBay. However unlike it's little brother the XEL-CF3, most other CF cards including genuine Sandisk simply do not work in this application. Also the prototype is a 4-layer board which due to its size is a little pricey. It would be far better to redesign it as a 2-layer board instead to keep the cost down. And finally, it requires precision mods to the case plastic in order to create the opening where the CF card can slide into the socket, not something very many people have the capability of doing especially if the end result is to approximate a factory finish look. If done poorly, at the very least you have done irreparable damage to your Atari's enclosure.

- Michael

Due to a long standing error that got missed, CTRL+SHIFT+Arrow keys were not rendering the correct key codes. Essentially they would just send the same code as pressing the arrow key alone, which was the equivalent to a CTRL+Arrow on a stock Atari keyboard. Basically it was missing the SHIFT aspect when combined with CTRL.

So both the TK-II Classic and the improved Universal 'J' version firmware have been corrected, and uploaded to the TK-II main page, as well as included in the XEL and XLD zipped compilation folders.

The classic version has moved from version 2.4 to 2.5, and is mainly provided to support the dual PS/2 keyboard aspect in the following products: TK-II-STEREO, TK-II-XEGS, TK-II-GS, TK-II-PB, and 1088XEL. This feature has been depreciated, and will no longer be seen in newer hardware such as the TK-II-PBJ.

The improved V2.6J version is the more universal TK-II firmware, and brings support for an AKI 'like' Console Function Key mapping, which is selectable between two modes: TK (Classic) and AKI. The AKI method is identical to what the Altirra emulator uses for the console and reset keys, thus making the transition between the two systems much easier. This mapping was adopted as the default for the 576NUC+.

To toggle between the two possible Console Key assignments, the key press combination of CTRL+ALT+E is used, with ALT+E displaying the current setting. This is non-volatile, so it will get restored to whatever the last setting was upon system power-up.

Another aspect of the V2.6J firmware that has hardware support in some of the newer TK-II boards, is the Arrow to Joystick mode, thus allowing the arrow keys to sit in for a joystick when selected. For the trigger, the Left-Windows key does the trick. Thus far there only two boards that support this: TK-II-PBJ and the ARROW2JOY-XLD adapter board for the 1088XLD. Pressing ALT+J will toggle the mode from standard arrows to joystick mode, and back again. It is a volatile setting, and will be restored to the arrow key default on a power cycle.

- Michael

Although it's not a mandatory must have upgrade for the NUC, having dual Pokey stereo output would none the less be very cool.

Normally if this were a stock Atari 8-bit computer I'd say go with the modern plug 'n' play PokeyMAX in place of the original Pokey chip. However there are two reasons that won't fly on the NUC, one being an incompatibility with the TK-II chip responsible for keyboard input, and secondly there were some clearance issues. Because the 576NUC+ is an extremely condensed version of an A8, there simply isn't a lot of room between chips and other required hardware. And due to a wider footprint of the PokeyMAX vs. the Atari Pokey chip, this presents problems, one being a standoff for the FujiNet daughter board getting in the way.

So not being one to throw in the towel when the going gets tough, I started looking at some of the old school solutions, namely Gumby as originally proposed by Chuck Steinman of Dataque fame. In his proposal he outlined a method of stacking two Pokey chips and then adding a circuit for address decoding to let them share space. Here's a link to the article he wrote in December 1989 about doing that very thing. What Chuck really accomplished back then, was to create the standard for dual Pokey addressing that lives on to this day, over 30 years after its initial development.

In Chuck's design he uses a single gate from an inverter chip to invert the A4 address line for connection to the original 'left' channel Pokey chip's CS1 pin, and then simply routes the non-inverted A4 address to the same pin on the stacked 'right' channel Pokey. This gives a flip-flop action between which Pokey chip is enabled, dependent upon the state of A4. To finish off the circuit, the 'right' channel audio output was handled in a pretty simple way with the addition of a single resistor and capacitor, using trim pots to balance the stereo output between channels.

Looking at the original Atari 8-bit circuit, a pull-up resistor was connected to CS1 creating a high (logic 1) on that pin, which can be easily overridden by external logic. Unfortunately I didn't do that in the 576NUC+ design, so for my upgrade that pin needs to be lifted.

In my design I wanted to match the characteristics of the already present 'left' channel audio circuit in the NUC, thus having the same output level in both channels and eliminating the need for any trim pots. I also had to keep what I'll call the Gumby Interface circuit relatively small, due to the lack of space in the NUC. So for the A4 inversion I was able to use two resistors and a 2N7000 N-Channel FET.

Next decision was where to locate the circuit board in order to avoid a point-to-point wiring mess of the required components dangling in mid-air. And because there was a limited amount of free space available, I chose to create an XRAM piggyback PCB to give both a secure and stable mounting platform, as well as to pick up power, ground, and the A4 signal.
Note: XRAM is my abbreviation for eXtended RAM.

This method of both mounting the PCB via piggybacking the XRAM and grabbing the prerequisite signals from that chip ended up working pretty well. And although it would have been super nice if I could have taken the more conventional approach, and piggybacked the original Pokey chip along with using sockets instead of soldering the Pokeys together, this simply was not an option so a compromise had to be made.

Here's how it looks installed in the 576NUC+ (the system ROM and 512KB SRAM have yet to be inserted). It turned out pretty clean if I do say so myself.

And now with the hard stuff out of the way, I can connect my amplified stereo speakers, and then sit back and enjoy some Stereo Pokey tunes. Life doesn't get much better than that.

Oh just to be perfectly clear... this project is purely a personal pursuit and will not see a public release for the gerber files, or ever get produced by someone like The Brewing Academy.

- Michael

I had one of Mr Robot's early prototype NUC-XE cases which was patterned after its big brother the XEGS. However this was not designed with FujiNet in mind, and would require some careful modding to get it to work. But I really wanted to house my naked 576NUC+ with its proto FujiNet board installed. So out came the files, drill bits, and a hot knife.

Luckily there appeared to be just enough headroom to pull this off. Although it would require creating holes right where the top and bottom of the case joined up, which was a tricky proposition to say the least.

After a lot of careful pencil marks and filing, I was able to create the initial holes for the LEDs and push button switches, and finished it off by holding the case halves together while spinning a drill bit to yield a smooth circle.

For the SD card, I heated up an X-Acto knife, and made a rough cut smaller than required, which I then finished off with a file to the proper size.

On the rear of the case I ended up making a square hole with a file for the reset button instead of a round hole like I had done on the front. I did this because the lid has a lip with an extra thickness which would have required some carving out in order to allow clearance for the body of the push button switch. And although I did this for the front buttons and LEDs, it was a lot work.

I also did something similar for where the serial programming header needed to protrude, but had to make it bigger all the way around so that the serial USB cable's Dupont connector would slide all the way in.

Luckily since the body of the toggle switch sits farther back, I was able to make a round hole between the case halves, same as what was done in the front of the case.

Note: I use a Prolific PL2303 serial UART to USB cable for updating the ESP32's firmware, but a FTDI cable would work just as well.

Next came some ventilation holes in the bottom, since things did get a little toasty with only the angled vents on the top side.

The holes were started with a small drill bit, and then followed up with a Uni-Bit to the desired size. I was able to get a chamfer by lightly touching the top edge of the hole with the next increment of the Uni-Bit.

Identical holes were added to the other side of the case for a uniform air draw from the bottom to the top via convection.


I am very pleased with the final result, although in the future, proper cases with FujiNet in mind will get designed by Mr Robot for production. In the meantime my NUC is now safe in its cozy little home, and is dwarfed by the XEGS sitting below.

And for that added a touch, a proper label was placed in the space already provided for it.

I got this from Sticker You and ordered a sheet of them to share with the beta testers on this project.

Also found some very nice self-adhesive clear silicone feet at Home Depot.

- Michael

Normally these chips which are re-programmable, go for $5 each as seen in other eBay listings. And I had previously bought a few at that price point. However they're no longer in production, so what you get are NOS ones that someone still has a stash of tucked away. What makes them really nice is that you don't have to have a UV light source to erase them, since it's done electrically instead. Making for a much better and faster programming cycle.

Now I can get OTP (One Time Programmable) 512K EPROMS by Microchip/Atmel for about $2.50 in single quantities, and they are in current production. But being a one time programmable device means that you better get it right the first time, and be happy with it forever. However unless you plan on investing in a chip programmer such as the TL866 Plus, this may not be many peoples cup of tea. Luckily for the 576NUC+ there really is no need, since The Brewing Academy will be selling them with pre-programmed ROMs when they go into production.

The 576NUC+ system ROM contains two different Operating Systems, two versions of BASIC, and two games. It could be handled by a OTP device as mentioned, and for most people that'll probably be OK. But for a few of you who love to be able to customize your system, a re-flashable ROM would be desirable, hence the reason I was looking for an inexpensive and readily available source of these.

So I went in search for that cheaper EEPROM, once again going back to eBay. This time I found another seller for the SST EEPROMS that was advertising a deal that I knew was too good to be true, but part of me was game to find out for sure since the seller was only asking for about $1.00 a piece.

Here's that eBay listing.

About 2 weeks after my purchase I received the EEPROMS with all 20 pieces appropriately packaged in several standard IC anti-static plastic tubes. So far so good.

I then proceeded to plug them into my trusty TL866 Plus programmer and initially tried to flash them with the 64KB system ROM image for the 576NUC+, at which point, no real surprise they all failed one after the other.

Next I tried to erase a few of them, and once again no dice with the same error. So I tossed in a known to be good chip, and it programmed without issue. But then I noticed a crucial difference in the chip ID. The one from JK Parts showed 0X DA 08, whereas the working chip was 0X BF A4. So I checked my stock of good chips, and all of them returned the same ID (0x BF A4). Next I checked several of the chips from JK Parts, and they all had that different chip ID of 0X DA 08. Obviously the JK Parts chips were not really SST 27SF512s but something entirely different (what are they really??? - initially I didn't know - hint: see note at the end of this blog post for the answer).

So with that revelation, I scrutinized the appearance and labeling on the top of what I will now call a 'REAL' 27SF512, and compare it to a 'FAKE' 27SF512 better known as the chips I purchased from JK Parts on eBay. As can be seen below it's rather obvious that something is amiss with the FAKE chip's labeling. For one the numbering is way too crisp and clean, yet the SST label looks a bit rough around the edges. And although you can't really see it all that good in the photo, the depth of the indentation is much more shallow on the FAKE chip, as if someone sanded off some of the material (which they probably did in order to prep it for the new label). The printing is resistant to acetone, which was the strongest solvent I had on hand, and it might even be etched like the original would be.

So what's on the bottom of the REAL chip? Let's find out.

Yep that looks like something one would expect. Now let's check out the bottoms on those FAKE chips.

Oh yeah... that probably shouldn't look like that. Did the seller have a picture of the chip bottom on his listing? No certainly not. Apparently they couldn't be bothered to sand off and reprint the bottom of the chips like they had obviously done to the top side. At this point it was pretty clear that these were not genuine SST 27SF512 EEPROMs that I had gotten from JK Parts. But what could I do since the seller clearly stated "No Returns" on his listing.

This story has a happy ending...

Thanks to a AtariAge member Mr Robot's sleuthing skills, he matched the FAKE chip ID to a Winbond W27C512 EEPROM. And when I plugged those parameters into the XG Pro TL866 Plus programming app, everything fell into place allowing me to do multiple re-flashes of the chip as seen below.

So long story short, JK Parts sold me a relabeled Winbond W27C512 chip instead of the originally sought after SST 27SF512 I ordered. Both chips are EEPROMS, and they can both be repeatably re-flashed and erased. So bottom line I still ended up with a good deal that still works for my application, but I'll have to relabel the chips to avoid confusion. And now thanks to the seller's substitution I also know of an alternate chip for what I was originally looking for.

BTW, I was able to flash all 20 chips successfully as Winbond W27C512's.

However even though in the end this will work for what I need, I can't in my right mind recommend ordering from this seller without at least verifying what the heck is going on, although it's probably a case of Cha Bu Duo (aka: "close enough" - thanks to Mr Robot for that bit of insight). I won't be posting a link to that eBay auction, and I won't change the title of this blog post either, since it really is a fake, or in other words a substitution of another chip meant to fake the characteristics of the one it replaces..

- Michael

Since the procedure for loading cassette (cas) files is uniquely different for the NUC/FujiNet combination I thought it good to outline that procedure.

The following assumes that you have your FujiNet Program Recorder configuration set to use the 'Pulldown Resistor' option. This selection is made using the FujiNet web UI via a browser, and then  saving it.


NUC-FujiNet Cassette Loading Example

1. Select a cas file (e.g., O'Riley's Mine from FujiNet.online) via the config menu, press ENTER, and it will be placed in disk drive slot 8.
2. Press OPTION (F4) and hold it, then press START (F2) and hold it until the system reboots with the characteristic BEEP, then release both the START and OPTION keys.
3. To begin the file load, momentarily press the START key one more time... the RED LED will light up, and then just a tiny bit later the loading tones will commence.

 

- Michael

Yesterday I assembled, tested, and shipped out three prototype NUC-FujiNet V1.5 boards to people in the Beta Team for their review.

When it comes to hardware development I can be very tenacious at fine tuning the design, but I'm afraid my patience for running thorough tests of all the different aspects is quite a bit less then desired. In order to insure that all of the bugs got squished out of this particular design iteration, I'll bow out and let the Beta Team have at it (Stephen, Herb, and Simon).

Assuming that all goes well in this regard, then AtariAge member Mr Robot will finalize the production FujiNet design he has been diligently working on, which will also incorporate the option of a top side-loading cartridge slot, as well as all the interface changes coming out of the V1.5 prototype (e.g., full SIO isolation when powered off).

And thanks to AtariAge member mozzwald, the SD card detect switch feature of this design has also been fully realized in the latest firmware release, so that we can now do SD card hot plugging and/or card swapping without the necessity of powering down or resetting the FujiNet board to reinitialize the card. This is an uber cool feature!

Production Design
Mr Robot's production board + case design concept is rapidly advancing, as can be seen in these simulated examples he created and first posted at AtariAge. And thanks to dimensional info coming from other members in the forums, he has hopefully gotten things sized to accept any and all cartridges ever made for the Atari 8-bit, including those wider AVG and SIDE carts, and the unique XE carts with the ridge sticking out of the back side.

Ultimately the plan is to offer it either as a stand-alone FujiNet minus the cart connector and raised case design, or as the full boat that you see here with the cartridge port inclusive. Obviously the non-cart version will be extremely compact with a minimal height requirement, thereby having a much lower profile lid for the case.

Needless to say, I think Mr Robot's design really hit it out of the park!

- Michael

Made several changes to the previous prototype V1.3 design, and now have another set of sample boards for testing being manufactured by JLCPCB - scheduled to arrive around the end of this week. BTW, the SD card issue I was seeing from day one, has been solved, and came down to human error as well as an incompatible SD card.

What's Changed?

The Cassette Motor Control line has now been buffered and switched out of circuit when FujiNet is powered OFF, and the SD Card Detect Switch is now being sensed by IO12 on the ESP32, and will eventually see future support in the firmware (Now Implemented in firmware version 0.5.879c407c).

This will be my last prototype, with the design already proven out by previously modding a V1.3 board. However I simply couldn't resist putting a bit of polish on the process, and doing one last board run with all the V1.5 changes in place. I also need a few boards for others to test so as to prove out the design, so having boards that incorporated all the changes was a prerequisite.

This time around I also wanted to properly pay homage to AtariAge members Mr Robot and mozzwald. Mr Robot deserving a call out for sourcing the switches, SD socket, and LED holders. And for the direction I got from his excellent PCB layouts that came before. And of course a big acknowledgement also goes to mozzwald the creator of the hardware design being used in the standard Atari FujiNet devices, which served as both my guide and inspiration. And a shout out to the rest of the FujiNet team for a wonderful game changing innovation known simply as FujiNet (visit FujiNet.online)

So the intention is to get a few of these out to the 576NUC+ Beta Test and Development Team, and let them run it through the ringer in order to shake out any bugs. Assuming that all goes well with that, then Mr Robot will take back the reins and proceed with the final production designs. There will be more to it then just FujiNet, so keep a look out for any posts he makes concerning that.

This new SIO interface circuit which is being proven out in this final V1.5 design, has been released into the public domain, and it is hoped that it'll see future use in other FujiNet related projects.

- Michael

In all cases, pressing control in combination with the arrow keys will temporarily reverse the present mode. So if you press CTRL+Arrows when in the normal 'PS/2 mode', that will produce symbols instead of cursor movement. Whereas if in 'Atari mode', will result in moving the cursor, with symbols only being rendered when no control key is pressed in combination.

Using SHIFT in combination with the PS/2 arrow keys produces the same symbols as the stock Atari keyboard, no matter which arrow mode you are currently in. SHIFT+CTRL when pressed with the PS/2 arrow keys, will not produce a character but instead mimic the same key codes as produced by the stock Atari keyboard for this same combination of keys.

The Insert key when pressed by itself will insert space to the right of the cursor, and when pressed with SHIFT, will insert extra blank lines below the cursor.

The Delete key when pressed by itself will delete characters or space to the right of the cursor, and when pressed with SHIFT, will delete lines below the cursor.

Home when pressed with either SHIFT or CTRL will clear the screen and home the cursor to the upper left. When pressed alone, will invoke a 1200XL function of simply homing the cursor to the left on whatever line it was on without clearing the screen.

End will invoke a 1200XL function to move the cursor to the far left of whatever line it was on.

PgUp (Page-Up) will invoke a 1200XL function and move the cursor directly up to the top left of the screen.

PgDn (Page-Down) will invoke a 1200XL function and move the cursor to the bottom left of the screen.

Those last 4 special navigation keys (Home, End, PgUp, PgDn) can be very useful when utilized in an Atari program,  especially anything that requires the user to navigate a menu. For a good example, check out the customized SDrive Control Program or AtariAge member flashjazzcat's SIDE Loader and the Uno Cart contributions. Also FJC's The Last Word makes good use of these keys.

As FujiNet continues to mature, it would be nice to see more of these  special navigation keys play a roll in navigating the TNFS directories in a similar way to the examples given above.

- Michael