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e5frog

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Posts posted by e5frog

  2. Posted

    Luckily this model has a bunch of easily replaceable logic chips, however it can be tricky to locate a broken one (piggybacking with a working chip sometimes help finding the problem). 

    If the VLSI-chip in a Channel F II break you're pretty much screwed. 

     

    Not sure what would be the next thing to check. The chain of logic chips between RAM and video output seem logic, IMHO most likely a single broken chip than several. Depends on what has happened though.
    http://channelf.se/veswiki/images/0/04/FVE_schematic_sheet_2_of_3.png

     

    74LS195 (D5) or Fairchild 93L00

    74LS298 (C4)

    7445/74145 (D2), for example if A0, A1, A2, A3 is locked to H, H, H, L it would give a low signal on FG GRN, H H L L for BG GRN

    9322 (C2), which has the function of a 74157 (Fairchild's 93xx series), sometimes there's 74xx-numbered chips on the board instead of the 93xx-ones.

    (D1), (C3)

    etc


    You could measure your way back, maybe signals change before a circuit changes but not afterwards... 
    Then there's the possibility that one of those large 40pin chips is defective, one thing at the time though. 

     

    BTW just checked some chips on one of my NTSC boards - the 5V died, haven't figured out why yet, bridge, massive 5V regulator or the electrolytic cap most likely. I meant to check what happens if you remove all RAM, will fix it...  later...

     

    • Thanks 1

  4. Posted

    Yes, green screen  means check 12V.

    If regulator outputs 12V correctly, check -5V on RAM and 12V on each 40pin chip - on the actual chip pins. 

    Those chips are often oxidized black (silver content). It can help polishing that off as it may cause poor connection to the socket. Even with 12V in, you may not get the outputs due to that. 

  7. Posted · Edited by e5frog

    V1.2 misses two bytes at the end to be an even 32KiB. Could be the reason.

     

    EDIT:

    When running ROM_patcher.exe (VecFlash ROM Patcher Version 0.2) that comes with VecMulti:
    https://www.vectrex.biz/VFRP.zip

    It patches DCNTRL but doesn't seem to do anything about the size - don't know if size makes any difference.  ;-)

  8. Posted · Edited by e5frog

    Is there any reason EDIH and Thrust wouldn't work? 32kB isn't anything special, right?
    Vectorblade would probably require some modification of the VecMulti to run, maybe Richard will attempt it if there's more of these IRQ-banking games coming out.

    Malban has explained in detail how to do it though so it seems likely.

    Not that it would require a lot of extra circuitry to have more banks without the need of the IRQ line but it's a neat solution.

    I'm in-between Vectrexes at the moment, so I can't check.

  9. Posted

    Looks worrying, I assume you pressed reset after (while unit being powered on) insertion? This has been missed before by others.  ;-)

    Console is not considered to run as it is supposed to unless reset has been pressed.

     

    The blobs don't fall off, the plastic covers sometimes do. The connector part is very rarely a problem.
    Not sure if the chip or bond wires are affected, just know that they fail - a lot more than other types, could be that one of them reacts with the blob material itself. Guess it could be a reason they aren't that common.

    I've got a board I "de-blobbed" in the 90's, have had a conversation now and then for a couple of years with a wire bonding guy here in Sweden (there aren't too many) but I haven't really been able to afford the service, would have been interesting to see if they can be re-bonded or if it's the chip itself that has suffered damage.

     

     

    • Like 1

  11. Posted · Edited by e5frog

    5 hours ago, Jorbus said:

    ... but 2 of them  (numbers 19 and 22) I cannot get to work...

    The #19 and #22 usually haven't aged very well. They often have rubbery blobs poured over the chips instead of the usual plastic covers, #19 more (all of them?) more so than #22.
    You can often see the bond wires through or going through that layer.

    They often share the same hardware so a #19 can be re-jumpered to #22 and vice versa. If you're lucky they can both be changed into working carts - or at least one.


    No need to open all your other carts, this is the only known board of this kind, Zircon where saving money or possibly intended for both games to be accessible.

    On the blob type version, by the 74LS02 on the PCB, there's two jumper wires. If you want a double release, and it's working, there's a possibility to put a switch there.

    1686650722_CheckersandSlotPCBsfront.thumb.jpg.d1771720a34b971aef3a83d2b064d7fd.jpg1858856175_CheckersandSlotPCBsback.thumb.jpg.025fcf3b1bc31352bc6e2a475f3c2f67.jpg

     

    Hpim9086.thumb.jpg.837a8c116ca1578e2782f191757bcfe1.jpg

     

    The other version, with plastic covers have been factory modified but IIRC it doesn't switch games if original trace is restored.

    Hpim9087.thumb.jpg.13cbc990d20b8b392b17a37c72a2c74e.jpgHpim9088.thumb.jpg.aa8623f1daae5cde4b1f1b805a003bf0.jpg

     

    On this #22 the trace is not rerouted, so probably no use trying to change anything:

    502904226_22alternativePCBback.thumb.png.f2445319ff9e24d10b6559464bc2f613.png1163415486_22alternativePCBfront.thumb.png.4648268ffce3e3f120bd7a4fb11c367d.png

     

    I think Dennis (FND) had details on the jumpers, in my opinion - don't mess with it if the game is working.

    There's of course the option to replace the board with a newly made PCB, at least the rest will be authentic.

     

     

    • Like 3

  16. Posted

    Yes - I've got the printed Democart box. There's a white box with both cart-label on it...

     

    Dennis has it:

    demo1-box-whitebox-all.jpg

     

    It's on the want list.   ;-)

    I know of carts 10 and 12 with the main label on white box and there's probably others, the white boxes with edge label seems more common.


     

    I have a moveable 3D image here:

    http://channelf.se/gallery/index.html

    Just click "VC = Fairchild and Zircon" and then "B" in the DEMO row, click "Watch full screen" in the top left corner... 

    Zoom with wheel, click and drag to rotate.

     

     

     

    • Like 2

  20. Posted

    2 hours ago, carlsson said:

    As for image converter, e5frog @Kurt_Woloch made one many years ago. I converted some pics already back in the summer of 2009, so nothing new.

    It's a bit quirky but works fine. I prefer drawing in a drawing program and then use my converter from bmp to gfx data (command interface). 

     

    Ditherton seems nice, it corrects the aspect as well. So you'll get that for free, then edit the png before making into data. 

    Dithering that large pixels is usually not very nice looking. Maybe over RF and a small TV. 

    Too bad it doesn't handle all color options. 

  21. Posted

    On 7/31/2020 at 4:32 PM, kleeder said:

    was able to test my second channel f as well today. its a system 2. theres video on my tv but no sound. do all system 2 channel fs use tv speaker for audio output or are there consoles with in-built speaker as well? am i probably doing something wrong when i connect it to the tv? or is there a quick way to find out if something is broken when i take a look inside?

    What Carlsson said... but if it's labelled "Channel F System II" it's almost certainly an NTSC system, if it's an Adman Grandstand V.E.C. then it's PAL-I

     

    The capacitors in the circuits that keeps the frequencies in the right spot may drift a bit in 40 years so you could try fine tuning your TV or fine tune the console. If it has drifted too far from the image carrier you'll get sound but poor picture. 

    You can see some of the adjustment possibilities here:

    http://channelf.se/veswiki/images/c/c6/Channel_F_II_composite_video_modification_overview.jpg

     

    DO NOT use metal tools for ferrite hex holes, carve a chopstick or whatever to fit in there if you don't have any proper plastic tools.

    You can adjust the metal screw with a plain screw driver but you'll need to lift it now and then to check the result as it will interfere with the setting. 

     

    Don't recall which one is which at the moment (I should document that some day) so count how much you adjust or put a mark so you can restore to the original setting if you mess it up. 
    I think the metal screw is to adjust the main frequency
    One of the schematics probably has some hints:
    http://channelf.se/veswiki/index.php?title=Schematics

     

     

    • Thanks 1

  22. Posted

    4 hours ago, kleeder said:

    such a thing would be super cool and helpful. whats the programmer + eprom part youre talking about?

    in case youre putting it higher on the priority list and it eventually becomes a thing, i'd totally be interested in getting one

     

    The System Fairchild carts are not plain eprom, when building a cart today you need extra circuitry. If then adding circuitry that needs access to the eprom, while it's still connected to the other chips, some measures must be taken to make that work without interference. Slapping a bus switch that switches everything is probably possible as a "quick fix". USB connection would open the bus switch and isolate the eprom. Then there's the other way around, how much needs to be disconnected from the AVR/PIC/whatever for it not to interfere in the other direction - if slapping bus switches on everything, there will be a lot of them.   ;-)


    There's a lot of ideas and feature creep that has dragged this out for years.
    I'll probably settle, initially, for a 64KiB slot and the plain "Chess RAM" to make it compatible with MESS, should work for any single software title out there at the moment. 

  23. Posted

    I have a solution where you hook it up to USB and then drop a bin-file on the device that pops up on the computer. 

    Basically the same as Mateo's  reprogrammable carts. Programmer will be inside the cart though and preferably with a USB type B (and not some small flimsy thing). 

    Left to do is... a lot. It would help a lot in development though so I might put it higher on the priority list. 

    Mainly it's a question of how much that needs to be isolated from the programmer + eprom part. 

     

     

    • Like 1

  25. Posted

    6 hours ago, atari2600land said:

    I chose to do this:

      

        ni %00111111
    ai 10
    lr 0, A

    pop ; return from the subroutine

      

     

     

    That will indeed keep 0-63 and the add 10 but... 

    noEor:
    lr A, S
    xi $2b   ; VERY IMPORTANT
    lr S, A

    You CAN NOT remove xi  $2b from noEor  you can make your additions after that  lr  S, A. 

    Else you'll ruin the pseudorandom chain and get stuck in a shorter, possibly repetetive number series. 

     

    Spark might have come from discharging capacitor or DC on the antenna output. 

    Depending on were discharge went it might have gotten damaged. 

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