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Kroko

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Posts posted by Kroko

  1. Posted

    What is a RAM, if not a collection of registers which is addressable for both reading and writing?
    Lets say it like this: If anybody woud ask me about 2600 bankswitching modes and ask if F8,F6,F4 or E0 required RAM, I would still say: no it doesn't. Would you say yes ? I don't doubt that a register is a storage element, but I don't call a chip RAM just because it can somehow be used to store information. To close this discussion lets summarize it like this: cats are more tolerant with regard to what is called a RAM chip than krokodiles :D

     

    BTW, how do you fit PB bankswitching into a "standard" PLD? A CPLD like the XC9536XL would have no problem, but the smallest PLD I would expect to be usable would be a 26V12, and those have been largely superceded by CPLD's.At minimum you need 13 address inputs, a timing input, a chip-select output, a timing output, and nine banking outputs (use tri-stating to select among them, and pullups to establish a default). So 14 inputs and 11 outputs.
    Maybe I should have said: Standard Programmable Logic chip. I didn't have in mind a certain chip type. The point was, that no RAM chip is required. Its not important if you do it with a XC9536XL or a 26V12. I am sure nobody would put a RAM chip on board (at least not if you take the krokodile definition of RAM chip :) )

  4. Posted

    The only other EEPROM I can think of, is the next step down, not sure if they are cheaper though.

    Yea, pricing for memory chips is somewhat strange. At least it does not only depend on speed or memory size. A few month ago, the 128K chip was

    cheaper than the 64K chip at my supplier. A week later, the 256K chip was cheapest and now the 64K chip is cheapest :?

  5. Posted

    A little overkill, no?

    Yes, that really looks like overkill at first sight. But it is still cheaper that an EPROM and I need a chip type that can

    easily be reprogrammed. Do you think there is a better chip type I could use ?

     

    Uhm, I don't see a logic chip on that board at all, all I see is a 7404 and a 27512

    What you see is the 4K version. There is no logic chip on that one. I also made a version with a logic chip, but thats not on the picture.

  6. Posted

    1) Do you have an idea of the price point for the boards?

    Price depends on lots of things, especially on how much boards I would order.

    But I have made a rough estimation of a possible end-prize:

    4K-Board: 6-8$

    BS-Board without RAM: 8-10$

    RAM board: 15-18$

    The programmer would probably be about 30$

     

    2) From the pictures, it looks like it eliminates the need for an eprom. Is this correct?

    Yes, the flash chip is on board.

     

    3) 7800 version? :-D

    I would like to have a completed design for the 2600 first. At this stage, its only a

    funny idea with a few prototype boards. But if I get the impression, that there are

    enough people who want such boards for the 7800, I don't see why that should be

    a problem ...

     

    BTW, Thank you for the cool hardware you've brought to us here (e.g. Kroko cart). It's people like you (and the homebrewers) that make this hobby so fun.

    Thanks, maybe I just need somebody to encourage me to go on with the above project.

    I will probably have to spend a lot of time until it is a finished usable product and I don't

    want to waste my spare time on something that nobody will ever really need ...

     

    Armin :)

  8. Posted

    Hi,

     

    Some time ago I was thinking about 2600 PCBs that can easily be reprogrammed

    with one click. I mean not only the content of the EEPROM, but also the content of the

    logic chip.

     

    I thought of 3 different 2600 board types:

     

    * 2K/4K board with no bankswitching

    * board with no RAM that supports all kinds of non-RAM BS modes as F8,F6,F4,EF,E0,F0,UA

    * board with RAM that can support the Superchip modes and 3E,3F,4A50,E7,CV, FA etc ...

     

    I have also made a programmer to program the boards. The Krokodile Commander could be used

    to programm the boards that are pluged into this programmer. It is downloading the ROM content

    and the logic chip content with one click.

     

    I am a bit stuck now, because I have no feeling if anybody would really need these boards. I also

    don't know how I should continue with development. Should they be made such that they can be

    hand soldered ? Or should they be 100% single side SMD, because then they are cheaper to produce

    by third party companies.

     

    First, I very much liked the idea of this PCI edge connector, because its an easy way to plug

    something with lots of programming lines into one single connector. In addition the connector

    is for free - no parts needed :) But now PCI gets older and older and I was thinking about

    changing the connector to "PCI Express", because these connectors will probably be available

    for a much longer time.

     

    I added some pictures and it would be great if you could give me some feedback :D

    post-3715-1149510438_thumb.jpg

    post-3715-1149510514_thumb.jpg

    post-3715-1149510588_thumb.jpg

  9. Posted

    Then tell me what that 74170 is

     

    Its a 4x4 register file with open collector output :) I am sure you already knew this.

    But seriously. You should not call a chip RAM just because it has a few registers inside.

    In that case you would also have to call the standard F8, F6, F4 bankswitching boards

    "RAM" boards. You can fit E0 in a standard PLD without needing a RAM chip, that is what

    I wanted to say ;)

  10. Posted

    This would also allow homebrews using E0, but is that really worth the effort since we have 3E?

    AFAIK, there are no boards available to homebrewers that support additional RAM. Yes, there are a few prototypes, like 3E or 4A50, but homebrewers can't buy or actually use them at this time.

     

    Especially since E0 requires at least two chips, one of which is a RAM chip

    Don't mix it with E7. E0 does not need any RAM

  15. Posted · Edited by Kroko

    Hi,

     

    you have a HEF4024BP counter on that board. It is responsible for

    storing the game (bank) number. On that chip, there are outputs

    O0 to O4 which can represent a bank (game) between 0 and 31.

     

    I didn't check it, but O0 to O4 need to be connected to A11 to A15 on

    the Rom chip.

     

    The first step to be able to play 4K games would be to disconnect the

    Roms A11 line from this counter and connect it to A11 on the edge

    connector.

     

    If you don't do anything else, you need to toggle the power switch 2 times

    in order to be able to switch to the next game. There is no easy way to avoid

    that. I think you would have to rewire the counter such that

    O0 to O3 are connected to A12 to A15, which would probably not look very

    nice on the pcb :)

     

    Armin :)

     

    EDIT: There is a little problem now, because the A11 line on the edge connector

    is not connected. There is a pad, but no wire. If you look at the picture of

    the top side of your device, it is the 5th pad from the right side :(

     

    Its very hard (if not impossible) to contact this pad such that you can still plug the

    cart into the Atari

     

    EDIT2: If you want to use a 64K EPROM, you first have to make sure, that the

    pinout of the chip on the 32 in 1 is really the same as for a 64K EPROM. If this

    is not the case, you would probably have to make an adapter socket. Is there

    a schematic for the 32in1 available ?

  17. Posted

    Hi, I'm currently trying to get the best price for 100 (or more) AtariVox PCB's.

    Here in the UK, it looks like it's going to cost about £200 ($372).

    The board is 56mm x 35mm, double sided with 77 holes + 3 drill sizes

    Do any of you hardware guys know how much cheaper it would be to have them made in the US ?

    Thanks...

    Richard H.

     

    Try www.myropcb.com and get a custom quote

    for your PCBs. Should be cheaper there ...

     

    On the other hand I have never ordered there

    before and can't say anything about their service

    apart from that is seems to be quite cheap.

     

    Armin

  18. Posted

    :ponder:

     

    Oh well. Good things come to those who wait patiently :)

     

    Sorry for the delay, but we got a baby and now I am extremely busy.

    So I have very little time for the hobby. I can still test a few hours

    from time to time ... but it takes longer than I had thought and I have

    less free time than I had thought ...

  19. Posted

    Does any one know if there are any areas of zero page that are free?

    These should be free for both reading and writing:

    $2E, $2F, 3E,3F, $6E, $6F,$7E and $7F

     

    Are there any areas where the data bus is not driven?

    I am not 100% sure what happens if you make a read access to these spots.

    But I am quite sure, that these spots are the only ones which COULD probably

    not be driven by the TIA if you read from them. I think for all other spots, at

    least some of the bits are driven ...

     

    Armin

  21. Posted

    That Krokodile Cart is exactly what I'm looking for. I'm not sure if it officially exists anymore, though, as it's not in the catalog and not findable using the search engine...

     

    PM Albert to join the waiting list. Then there is a good chance you can get one soon ...

  23. Posted

    Had some time to try it.  Works perfectly with both power adapters in use.

    1020105[/snapback]

    Great ! Can you please look on the supplies and tell me the specs. I guess 9V, but I would be interested in the current specs (mA) and what type of console you are using.

  24. Posted

    I've tried 2 power adapters (I bought a new one for programming the Krok Cart) and have cleaned up the cartridges and the cart port.

     

    Haven't done anything to the power switch - I'll have to check that out.

     

    After some other research, I think it might be the regulator since it only happens with the Krok Cart and I think it needs more power.

     

    I'll be taking apart my Atari on Monday as I've got plans for the weekend.

    1019893[/snapback]

     

    Have you also cleaned the Krokodile Cart ? It needs to be cleaned from time to time. You can try what happens if you let the power supply connected to the Krokodile after programming. Then you should no longer have power problems, because then the external Krokodile supply will feed the Krokodile and the other supply will only be powering the Atari (at least almost). Would be interesting to see, if the Krokodile behaves differently if it has its own power-supply connected..

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