Indivision ECS V3, or how we deal with chip shortage, part 1

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Don't Panic. Please wash hands.
  • Indivision ECS V3 will replace Indivision ECS V2. Although very unusual for iComp, I had to make a re-design without actually adding new features. The main reason why a new design was required was the global chip shortage that you've surely heard about in the media. Two rather low-cost chips, and the main FPGA were either wildly expensive, or not available at all. I was lucky enough to find a small quantity of FPGAs on the free market for a moderate premium of "only" 160%, but could not find the right footprint part for the H/V sync driver and the data drivers. Instead of the SC-70 package for the H/V driver, I found a slightly bigger part with the same functionality. Luckily, that part of the board had enough space:

     

    The data drivers were a single 16-bit chip on the V2 design. This became unavailable these past months, so I replaced it with two 8-bit drivers:  

    The above picture shows another change, which has nothing to do with chip shortage: Instead of soldering the male-to-male adapter directly to the board, I decided to solder a socket to the circuit board, where the male-to-male adapter will be inserted. Background of this decision is a few service cases where pins of this adapter broke off, and it was very tedious to replace the part. The improved order of parts makes V3 much more servicable, as the adapter can now be exchanged without soldering. I'd expect that most useres can replace the adapter on their own, so shipping the flicker fixer to us for service is becoming less likely to be required.


    Another thing that got hard-to-find was the IC that I've been using for the 25MHz oscillator. I wasn't too worried when the distributor told me that the lead time for this part is just over 50 weeks, as we've had complaints from A600 users that the crystal conflicts with the RTC module in some cases. I have therefore decided to buy 25MHz integrated 3.3V oscillators. While this is considerably more expensive, it is only a small contribution to the overall price increase, and has the added benefit of being much smaller than the HC49S-sized crystal of the V2 design:


     

    Note that there are a few unpopulated parts for different vendor's products, so I'm prepared for the day when this oscillator gets hard to find.


    One thing that is truly different from the V2 design is the output stage. On a component level, it does look almost the same as V2, but went through an expensive CE approval process, and vastly improves picture quality when used on problematic Samsung monitors and similar models that use the same input stage.


     

    The new output stage uses high-frequency transistors as drivers, allowing much sharper edges at higher drive strength, eliminating "ghosting" that was described with certain problematic monitors.


    Another thing we have improved is compatibility with motherboards that have a mouse/joystick multiplexer chip from Mitsubishi: While V2 had trouble dealing with the extremely long propagation delay of this chip, the CPLD of the V3 design deals with this problem without the need to adapt to a specific Amiga main board revision. This CPLD code can also be applied on the V2 design, so we now have a solution for existing V2 customers as well.

  • Jens

    Approved the thread.
  • would love to see a VGA to DVI or HDMI conversion.

    You can of course try an adapter - I haven't tried any of those cheap ones myself, but they should work, at least for Vesa output modes.


    Is this the same as the previous revision with a VGA output only?

    Yes. Adding a digital output would have added way too much to the cost, and I personally consider the OCS/ECS systems lower-cost. With a VGA output, you can use pretty much any flat screen that's available on the used market. With 4:3 aspect ratio being totally out of fashion, you can strike nice deals on a flat screen for your A500/A2000.

  • In the A600 I use the eX601n memory expansion from Lotharek

    Will Indivision ECS V3 work 100% for me without any problems and without restrictions?

  • In the A600 I use the eX601n memory expansion from Lotharek

    Will Indivision ECS V3 work 100% for me without any problems and without restrictions?

    We will only guarantee that for our A603, A604 and A604n expansions. I'm aware that our products are being copied by other companies, but if you want such a guarantee, you'll have to ask there instead of here.

  • Would you say that the higher frequency output transistors themselves is the single cause for less/no ghosting improvement on the ECS V3 VS V2? So let's say one changed only the output transistors on the ECS V2 with the same type that you now use in the V3, would this improve things with the ECS V2?


    If so, would the same be possible with the TC64 V2?


    Or one would still need a full patchboard (which you have mentioned in the past) with more components than just the transistors for this to improve things?

  • Would you say that the higher frequency output transistors themselves is the single cause for less/no ghosting improvement on the ECS V3 VS V2? So let's say one changed only the output transistors on the ECS V2 with the same type that you now use in the V3, would this improve things with the ECS V2?

    That won't work, as the different transistors also need a different base current. You also need to change a few resistors, which is what I intend to do on the patch-PCB that I have written about so often. These resistors will be very odd values, probably from E96 or even E192 series, so "hardly available to the mere mortal".


    If so, would the same be possible with the TC64 V2?

    A similar patch-PCB would certainly be possible for the Chameleon V2, yes.

  • The board that uses the Pi that is similar to your board has HDMI output. If you build it people will come and buy it.

    Indivision ECS V3 has quite a few advantages over an SoC that attempts to convert Amiga pixel data - thanks, but no thanks, as iComp is not about going for second-best.