Piotr D. Kaczorowski

I'm going to check and install core with NTSC today.

Thanks to @tschak909, Fujinet is my first tool The above 600XL has VBXE and SRAM 64K v3. I have prepared an ATR with the Rocky palette, but it is formatted in the SDX format. Using UltimateCart, I launched SpartaDOS X. SysCheck 2.2 provided Atari with additional memory and HSIO.

For example, you should copy the two files, FC.COM and v2x126a3.rbf (which is for HARDWARE: VBXE 2.0 / 2.1, FX core v1.26 with NTSC palette), to an ATR file. Then run FC.COM, flash v2x126a3.rbf to the first empty slot, and set it as bootable.

@Overange, I think it was decided on a similar basis that faulty GTIA and keyboards without springs could be put into the XE. For me, it's an obvious cost-cutting measure. It's also not the case that the electrolytic capacitors in Atari are eternal, while for example in the C64 they need to be replaced. Electrolytic capacitors have a typical stable lifespan of 10-15 years. They also dry out and lose their parameters. I replace the capacitors in my Ataris. I replace 470uF with 1000uF (as in XEGS), choosing a polymer super low ESR. Here I'll add that on XE boards, I always replace the DRAM memory with SRAM, and when installing VBXE, I remove Freddie so that the 3.5MHz signal goes directly into the main board from VBXE. As I wrote about the noise level on the ground plane, in the case of processors it's usually around 30mV, but Freddie generates 100mV. See what an increase that is compared to the 15mV from the 600XL. Unfortunately, adding your own holes every 0.4" doesn't yield the same results as the factory implementation. Despite that, I believe they should be introduced. Notice that this is present in all models except for the 130XE boards. The XEGS boards also have these holes, and the noise levels there are significantly lower. We need to understand how the "F" series works. The technology and design make it so that these circuits, without introducing too much capacitance on the signal lines where they are connected, achieve speeds up to 125MHz. So, when replacing the 74LS08 with 74F08N, it's not about the speed of the gate, but rather about reducing the parasitic capacitance on the main board. An additional effect is that the gate operates faster. Because the Atari design is based on NMOS and is more analog than digital from certain perspectives, everything still works. The prototype of the O2/Fixer consists of two 74F08 chips, where the first one functions like the 74LS08, and the second one creates four additional twin BO2 signals that can be directly connected to the Atari circuits on top. You can also reduce capacitance in a completely different way, but it's significantly more expensive. We can imagine replacing the PIA with W65C21N (WDC PIA NMOS), Pokey with PokeyMax, and GTIA with Sophia 2. On the XE board, I also had Freddie removed, so it wasn't connected to the BO2 line. Such a change was enough to sufficiently lower the capacitance of the BO2 line so that VBXE with Ultimate 1MB, Rapidus, and external SIDE3.1 could operate at full speed even in 20MHz mode without interference. I've proven through a reverse slow degradation system test that we can, by replacing elements step by step, increase the system's stability. So with the full installation of add-ons that I talked about, SIDE3 wouldn't start at all. After replacing one element, it started in 6502 mode. After replacing a second element, it also started in 65C816 mode but couldn't read the SD card. After replacing a third element, everything started working beautifully. I then returned all the old chips to the Atari and built a prototype of the O2/Fixer where all the circuits received signals from the twin BO2 signals. Everything worked beautifully. Switching to 1-gate and AHCT is a matter of productizing lab work, reducing costs, adapting for pick&place production, and miniaturizing without taking up additional space on the main board. This refinement has already been implemented by Lotharek, who adapted the design to conditions allowing for the production of the O2/Fixer. Theoretically, one could also use low-profile sockets, but unfortunately, such gold-plated low-profile sockets would probably triple the cost of the O2/Fixer. I personally didn't negotiate any additional compensation for this project, so as not to increase the product's value. This particular product should be widely available, as it stabilizes the operation of projects that people have often already purchased. In the end, it's all about people having stable computers so that we can continue to have fun, rather than having computers sitting in cabinets waiting for better times. In my opinion, for owners of the Ultimate 1MB, the O2/Fixer device is rather a must-have. According to the assumptions, the memory should be controlled by BO2, not by O2, for example from SRAM 64K V3. This is a matter of further system stability, as well as functioning with extended memory, not only in RAMBO mode but also in CompyShop mode. Remember that in the second mode, Antic has access to a different bank than Saliy. The BO2 and O2 signals are often confused in Atari schematics and descriptions of Atari ICs.

I am not yet an Altium user, unfortunately, but it has been recommended to me because of its significantly more advanced features, such as easier multi-layer board design, HDI, and various simulations. These things are probably achievable in KiCad as well, but they are more complicated or less refined.

@_The Doctor__, For the NTSC region and the American history of 8-bit Atari usage, which is somewhat different from the European experience, I think an interesting topic will also be the native 80-column mode, which can be used for BBSs and CP/M. Among the new features are, of course, SpartaDOS X and a CON: driver that can be used with other programs.

I understand that someone might hesitate to use a program for flashing anything, but let me clarify that the NC.COM program is trivial to use. Essentially, it shows the slots where you can load the cores. You have to select a core from the list beforehand. Then you load the chosen core into the designated slot. After loading various slots, you can set which one is the active booting core. So, you can load several versions, such as FX, GTIA, FX with an NTSC palette, or FX with 320KB Rambo and an NTSC palette.

@Overange, I hope you know that if you want to create a truly professional board from scratch, you're better off with Altium Designer rather than KiCad...

My recommendation is that you take a look at the 600XL board. Everything is best done there. After that, it only gets worse. If you perform a loop probe test using an oscilloscope and its probe with the connected ground at its tip, you will see almost like a radar what the noise level is on the main board. On the 600XL, it's usually around 15mV on the ground plane. On subsequent computers, this noise is much higher. Also, look at the small holes around the ground plane. These are not decorative holes (which are not on the 130XE boards), but electromagnetic wave interference breakers. As for the BO2 line (Buffered Phase 2) itself, ideally on a new board, you would want to attach its twin copies to subsequent circuits (as is possible with O2/Fixer). This matters if you are using original NMOS technology chips. If you start using replacements: PIA -> WDC PIA NMOS, GTIA -> Sophia 2, Pokey -> PokeyMax, etc... the BO2 line is relieved. By the way.. If you take a book about the 6502, it indicates that a maximum of 1 TTL and a maximum of 130pF capacity should be connected to O2. Therefore, for example, if you connect to the O2 signal (pin #39 on Sally) with an oscilloscope probe with a 1x multiplier (which has 135pF on Keysight), the expansions become unstable. SIDE 3.x stops working altogether. In my opinion, it's worth inviting @candle , @Simius, and maybe even @electron can be tempted to join the discussion. These guys have significantly more practical experience. I am refreshing my knowledge after 20 years since finishing my studies (Faculty of Electronics and Information Technology of the Warsaw University of Technology).

If there are no takers, I can probably also prepare such ATR images.

Inside the package, you will find four files. Two of the files are for VBXE 1.2 and the other two are for VBXE 2.x. Each set contains a standard core file and a core file with 320KB of Rambo extended memory. On Lotharek's page at https://lotharek.pl/productdetail.php?id=53, you will find a section labeled "Last CORES 1.26." Within this section, there is an NC.COM file that is required for flashing cores to VBXE. You should copy the NC.COM file and the appropriate core file to an ATR disk image. Then, you can flash it using, for example, SpartaDOS/X. That's how I did it.

For those who are asking about NTSC Artifacting, I'll just mention that new devices are planned to be released later this year and early next year that will add NTSC Artifacting in post-production technology. These will work across all cores, including the VBXE FX core. Specifically, these are the SAVO/HAVO boards and the new Medusa 2024. These are somewhat unofficial announcements.

:)))))))))))))))))))) I need to send flowers to the lady from your company's secretariat. She may have violated "RODO" a bit, and I was shocked myself. The important thing is that the issue concerned a larger matter. In the NTSC region, the focus is currently on improving video output and the 80-column mode used for BBS and CP/M support, which were popular in the United States in the early '80s (Poland has a completely different history). I've spoken here with colleagues from various demo scene groups, and they are announcing more applications and games for VBXE. Thanks again for your help and for creating VBXE in the first place

BOOM! WE DID iT! Thank you, everyone. Especially @tebe, @candle, @flashjazzcat, and of course Electron , who found the time and built the core version 1.26 for VBXE with native NTSC palette. VBXE_FX_v126_cores_ntsc_palette.7z

We did it! :))))))))))))))))

Thank you very much to the entire community for the ongoing discussion since 2017, and for the comments in the last few days and hours. The 'NTSC_Contempt' palette has been sent to Electron with a request to build an official VBXE core for the NTSC region specifically with this palette.

Certainly, it's worth mentioning that the price will take into account three factors: components, time-consuming assembly, and of course the R&D process associated with Intellectual Property. Let's spark our imagination... For instance, let it be.... $59 - BASIC, and $89 - PRO ... however, these are not the final prices.

Short update regarding the product specification: HAVO will consist of two boards. One will be mounted in the computer, and the other will be a daughter board plugged into the first board. In this way, it will be possible to upgrade to the next version of the board without desoldering the entire assembly from the main Atari board. Two modules will be available for HAVO: one basic/budget (classic) and the other advanced (pro). The PRO version will include very fast converters, capable of full-frame image processing, so that demos containing fast scrolls are also adequately represented. The PRO version will also have a post-processing module, switchable from the Atari level, which will allow operation in several modes: off, with enabled PAL Blending, with enabled NTSC Artifacting for Atari 400/800, with enabled NTSC Artifacting for Atari XL/XE. Both boards will have special circuits that eliminate noise from the Atari as well as secondary noise from the cables to the TV/monitor (voltage regulators, filters, and galvanic isolation). The boards will include audio mixers (GTIA, SIO, EXT AUDIO, COVOX + STEREO POKEY) and conversion to digital form, which will go into the HDMI port.

NTSC Artifacting / PAL Blending - post-production modules that will be available at the end of 2023. NTSC Artifacting (and PAL Bleding) will be added later this year. However, it will be added externally as part of the Micro HDMI output board project (HAVO), which will include a post-production module during conversion RGB to digital signal. Regardless of the set VBXE core, they will offer the following options: no post-processing, PAL Blending, NTSC Artifacting Mode 1 (400/800), NTSC Artifacting Mode 2 (XL/XE). A similar post-production module solution will be featured in the upcoming new version of the Medusa upscaler designed by AcidMaker of Lotharek Team. (My yellow posts are general comments on the thread).

So from what I'm reading, you support the NTSC_Contempt palette as a release candidate. Artifacts are an entirely different matter, which, we can say today, are the result of kind of post-processing performed by the TV. We know that this is a subject that would be attractive to the NTSC region, but it's a completely different topic, and I'll ask about that in another thread. Let's focus on the color palette - that is, whether the blue color in the SELF TEST in the memory test is indeed that shade of blue...

Maybe... It's hard to say, because here in Europe we have PAL. VBXE will not standardly have just NTSC Articting, but this topic will be supplemented at the end of the year. Please, let's focus on the choice of palette. If you have the opportunity, please check the proposed palette on Altirra and see if games and programs look at least 90% the way you would find satisfactory. We know we won't please everyone, but it's a good start (or perhaps more of a continuation?). Let's move on.

"F" - First help I tested more then 20 motherboards, and more then 30 sets of Atari ICs this year. The main problem was parasitic capacitance not timings. I had different results on timings. The best part is that NMOS technology is more analog then we think at start. It works a bit like a set of vessels and water faucets... The parameters and their ranges can be quite broad. An important factor, however, is the connection of elements - for example, the number of attached TTLs and the line capacity in pF, to which our extension creators didn't give much importance. If you're interested, I'd be happy to share my experiences in a private conversation or on another thread.

A brief explanation. VBXE is built on an FPGA and it's not possible to implement a permanent change of colors within the FPGA itself. What can be done is: build a core with a single standard palette for the NTSC region install Ultimate 1MB, which has the ability to set an alternative palette upon computer startup (e.g., an NTSC palette).

@wildstar87, thank you for your comment. Actually U1MB uses NTSC_Contempt palette. Currently it is the release candidate.

Thank you for your comment. Please check this sofware with NTSC_Contempt using Altirra emulator. If you haven't suggested another palette, then NTSC_Contempt remains the release candidate.