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e5frog

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Posts posted by e5frog

  1. Posted · Edited by e5frog

    The green field means something is written in the palette column, either going too far left (decrease in x) and looping over or too far right.

    Several rows, do the appear at the same time or in a special order? 

    Try and skip parts that are plotted and see if you can figure out which part causes it. 

    A few times I've had problems with pixels ending up in the wrong places, it was enough to clear ports used before plotting. 

    Maybe out or outs have been used on the wrong port. 

  2. Posted · Edited by e5frog

    The "bz doEor" won't work as "lr A, S" doesn't set flags. 

     

    As in  my example code:

    http://channelf.se/veswiki/index.php?title=Snippet:Pseudorandom_numbers

    Where I use the combination of "clr" and "as 1" you should use "as S" to make "bz doEor" meaningful. 

    Then you have "lr A, 7" where it should be "lr A, S". 

    ... as well as everywhere else r7 is used - should say S. 

    If you use r7 later, end with lr A, S  lr 7, A. 

     

    So:

      

    LFSR:             ; Linear Feedback Shift Register
    ; save the return address
    ; r0 as temp reg
    ; 0o36 stored rnd no


    lisu  3
    lisl  6

    clr
    as    S
    bz    doEor
    lr    0, A        ; Save original number in r0
    sl    1        ; shift one step left
    lr    S, A
    bz    noEor

    ; Do XOR if b7 was 1, workaround for missing carry on "sl"
    lr    A, 0
    ni    %10000000
    bz    noEor

doEor:
    lr    A, S
    xi    $2b     ; Do the XOR thing
    lr    S, A
    
noEor:
    lr A, S
    xi $2b   ; VERY IMPORTANT
    lr S, A

; if needed:
;   lr A, S
;   lr 7, A

; Now you can handle your number, store in a temp register
; or fetch reg 0o36 in your code and then handle it locally. 

; If wanting to check if valid number, repeat if it's not. 
; (Can be done many many ways) 
;   ni %00111111

;   keeps only 0-63

;   ci 14
;   bp LFSR

; a number under 15 causes a loop for new number
; Possible numbers are [15,63] 

;   inc
; Now it's instead [16,64] in A

;   lr 0, A

; Stores the edited pseudorandom number in
; register 0 for temporary (or other reg - not reg 0o36) ; keeping, if it can't be left in A

; You'll now keep getting a new pseusorandom number in reg 0o36 every time you call LFSR
; ...unless you write to it anywhere else in the code. 


    pop ; return from the subroutine

     

     

    • Like 1

  3. Posted

    I usually name the registers 'O'61, O61 or 061 (for octal 61). It's a bit annoying that they're named differently in MESSUI debugger. IIRC they're 0-63, if you want to set 062 to a value in the debugger a quick calculation is needed, it's R50 in debugger...  Seems 0o62 would be a way of writing it, like 0x32 is for hex. 

     

    That's why I usually make an initial table with octal and decimal numbers. 

     

    ISAR can be loaded directly from A as well. 

    LI $32

    LR IS, A

    (and fetch the value with LR A, IS) 

    If using that way of loading ISAR you can increase and decrease the ISAR number without thinking about the lack of carry on ISAR where octal 67 would change to 60 after an increase instead of 70.

     

    For the LFSR to work you need the previous number safely stored. Make sure you continue from the whole 8bit number and not your partial one. 

    Seed one initial time by counting up a number while waiting for user interaction, when done place value in your LFSR memory position. If waiting for a keypress you can check that it's not pressed before allowing to stop counter - as it would otherwise be possible to get the same seed and then know the series of numbers that follows. 

    When needing a random number you call the LFSR routine once. It's supposed to read from the reserved memory position and then write the new number there. Either you use it directly from A, store it in a temp position or read from reserved position. 

    User actions in the game could generate a LFSR call to increase variation passing a position on screen, how many times a maneuver is done etc. 

     

    I'd love to get involved but I need to get some other things done.  ;)

  4. Posted · Edited by e5frog

    Check that you're not using the LFSR register for something else. 

     

    Also wondered about 1k demo... 

    I attempted IK but lost my geist when I realized the lookup table for animation frame and distance for each player would be a lot of work. 

    IIRC there's one hit possibility, then it just resets to start position. 

     

    If cheating, smaller players with less options perhaps. 

    It's hard to revisit old stuff. 

  8. Posted

    Seems atari2600land hasn't released the new information on trimerous. 

     

    In an amazingly impressive effort all the circuit boards have been soldered and are awaiting transport - as soon as box and label prints are done...

    Seems holiday is interfering with the printing, but sooon... 
    Tetris boxes will be printed at the same time.

  11. Posted · Edited by e5frog

    All orders made until today has been shipped. Still have some boards left (got another set as bandaid on the wounds as we say in Sweden - but in Swedish...) but I'm missing one type of IC and also SMD capacitors, they should arrive the coming week. 

     

    I have a couple of other things I need to finish, so I might be less responsive for a while (weeks, months...? ). 

     

    So

    Grab One Now

     

    Thanks everyone for your support. 

    • Like 1
    • Thanks 2

  12. Posted

    2 hours ago, carlsson said:

    To be honest I thought there would be a dip in the retro gaming prices by now or very soon, but oddly it seems my expectations have failed, that for each company closing down, there is more and more spare money in circulation for people's hobbies.

    Poor people sell, richer people buy - as they aren't spending money on other things, sitting home, polishing their collection maybe - there's money to buy stuff. Especially if one of those really unusual things pop up.

    Still got my job, not that I have money to spend at all since the wife finished studying (five years) and currently seeks employment in "specialized" healthcare and they all seem to be caught up in this Covid-19 business not let anyone have vacation etc. Hoping she gets the second job she interviewed for, we'll see.

    We work 24 hours a week at something like 95% of the salary instead of 40 hours, so that's pretty neat. In two months we'll see if we're back to normal again, seems orders are popping in a lot more than before at least in bursts. 

     

    I have sold a few cartridges more than the mean number over the first quarter (sounds really business-y). Tetris is coming along, there's just 2 more features I must have, will check with the buyers about the rest, could probably spend many more months on it.  :D

     

    So, for now it seems it's not bad to sell, if it's something unusual at least. 


     

    • Like 1

  13. Posted · Edited by e5frog

    11 hours ago, poppalarge said:

    But if you ever do decide to sell, I'll be here!

    If I'm offered a $2200+ sure, otherwise it would go on eBay - even though comission and PayPal fees would be a drag. 

    11 hours ago, Blazing Lazers said:

    The seller also should have sold that second box separately, perhaps with a moderately high BIN. It won't be a surprise to see the buyer do exactly that. 

    Agreed. 

  17. Posted · Edited by e5frog

    Not sure MESS handles the timer interrupts, I have thought about testing it out myself when timing stuff (seconds counter or whatever). 

    You'd have to use DI/EI so it doesn't mess up the code. Do you know if the interrupt flag will be held until there's a EI, if it's disabled when the interrupt happens?

    If you get any results, please share. 


    Nice table, it wasn't readable on my phone but it looks nice on the computer screen.

     

    I wondered about that as well the other day when checking the table after finding an error. Not sure MESS is the best place to try it, if they have used the same information. It should be possible to check it in the MESS/MAME code (somewhere). 

     

    According to Lowell Turner those $xF result in NOP:

    http://www.nyx.net/~lturner/public_html/F8_ins.html

     

    EDIT: 

    Registers 12, 13, 14 and 15 are the K and Q 16-bit registers so perhaps it would be odd to be able to call r15 directly like that. 

     

     

     

  18. Posted

    Update:
    Box awaiting some text for the back side, got some help with that, then it's ready for print.

     

    Moved code to another editor for better overview and syntax checking, to date I have made 974 code compilations (where the code is compiled into binary) , some with small and some with larger changes. Many wasted since it only worked in emulation...   :'(
     

    Also want to thank everyone for their patience.

     

     

    • Like 2

  20. Posted

    Hey there, still at it.

    Haven't found a solution to the mentioned technique used with the emulator. I'm considering a hardware solution but it feels like cheating and would prolong the development as it might require changes in cartridge hardware.

    Anyway, there are a couple of small details I want to sort out, it's those last ones that takes the most time.  ;-)
    I may have to replace some routines to be able to get the different colored blocks I want instead of mono-colored blocks. There's three to work with, so why not use them all?  ;-)

    • Like 1

  22. Posted

    The image shown above is most likely displaying other colors because of the crappy video signal, colors bleed, they have checkered pattern etc. 
    It's a well known way of mixing colors on other vintage systems, using the limited quality of RF or composite video signals. 
    I think they aimed for that effect in Alien Invasion where there's a checkered pattern of blue and green at the bottom.
    ... there could be some defective logic chip though, who knows. 

  23. Posted · Edited by e5frog

    12 hours ago, poppalarge said:

    Is the democart not just built-in hockey with instructions?

    Well... the "computer aided teaching"-instructions is what is the Democart, I think it uses the console hockey code for display etc and final option to play.
    ... and there's an Easter Egg as well. 
    Democart 2 is "just" pictures of games with titles (not all of them the release title) Black Jack doesn't even display properly - due to delay after gfx loading is too short. You get nothing on a fast machine and stripes on a newer version. MESS runs it fine, it has no such limitations. 

    If collecting games to play there's no reason to get neither one nor the other. 

     

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