UNROM question

ThrashOmenThrashOmen
in The Brewery
Since the board only has 28 pins, and I have to position it with the bottom 28 pins in the holes, What do I do with pins 1, 30, and 31? 



2 is connected to pin 24, and then pin 16 (gnd) is connected to hole 22 (under pin 24)

Comments

  • LincolnLincoln
    1 and 31 can be left floating. pin 30 can be left down since it's either NC or A17 which is never used with UNROM. Just make sure you double your bin properly before programming if you're using 27C020's.
  • removed04092017removed04092017
    VPP (1) should be grounded. /Prg (31) should be high. 30 should be connected, or you could just leave it floating if you like to play dangerous, like Lincoln said.
  • ThrashOmenThrashOmen

    Originally posted by: Lincoln



    1 and 31 can be left floating. pin 30 can be left down since it's either NC or A17 which is never used with UNROM. Just make sure you double your bin properly before programming if you're using 27C020's.





    Well I'm using a 27C1001, is that okay? The .program bin comes out as 128k, so a 1meg chip is what I should be using correct?



    In another tutorial I saw that they connected 1, 30 and 31 together with a wire. I did this and the game does not work :/ I am going to try again, and do I just leave pins 1 and 31 up? What do I do with pin 32?



    3Gen, I should connect pin 1 to pin 16?



    Also pics of my board below:
  • removed04092017removed04092017
    32 and 31 should be connected, and should both go to the hole 28 on the PCB, the last one on the right. You can possibly tie them all together, but I'd ground any pin that's NC. Pin 30 is the one over hole 28 you need.
  • ThrashOmenThrashOmen
    I didn't even think of this, perhaps this would be helpful, I'm trying to put Streamerz onto a cart for myself, it's pretty rad, just discovered it the other day browsing the board.
  • LincolnLincoln
    27C1001 is fine, right size and equivalent to 27C010.



    if you're being really thorough,



    pin 1 (Vpp) should be connected high or low,

    pin 31 (/PGM) should be high



    for pin 1 it doesn't matter which if you're reading, but I haven't run across any chips that care when it's floating. other pins disable or enable output before Vpp is considered.



    for 31 there are some chips (HG27C101) that require it high, but most in practice do not care.



    pin 30 on 1 meg chips is "not connected" (NC) so it does not matter at all. I find it's easier to leave it down.



    also if you are doing UNROM games, carts with Konami pcb's are much easier to work on. look for carts with "24" printed on the back label. Silent Service, Double Dribble and Skate or Die are common like this.
  • removed04092017removed04092017
    Lincoln, Vpp NEEDS to be grounded. It's either 12.5V or 0. 5 will mess the chip up, more than likely. It'll change chip per chip, as that is undefined behavior.
  • LincolnLincoln

    Originally posted by: 3GenGames



    Lincoln, Vpp NEEDS to be grounded. It's either 12.5V or 0. 5 will mess the chip up, more than likely. It'll change chip per chip, as that is undefined behavior.



    according to this 



    http://pdf.datasheetcatalog.com/datasheets/120/227198_DS.pdf



    Vcc or Vss are fine for pin 1 for read mode.


  • ThrashOmenThrashOmen
    I still have it wired how I did it the first time, this is what I get when I turn it on, a perfect intro logo which teases me with it's hatred, and the second picture is what I get for a main menu. It freezes with these garbled graphics :/
  • removed04092017removed04092017
    Actually, just checked, datasheet seem to be okay with Vpp being 5V...that's very odd, I thought most were GND when not programming...maybe I'm thinking of a different EPROM.
  • GorillazeroGorillazero
    HAHA, and THIS is why we need to have the Maskrom and other details on a sticky.



    This was asked by me about 5 years ago, and asked by another two dozen or so since then.







  • ThrashOmenThrashOmen
    HAHA very good sir.



    Anyways I figured it out! I was thinking about how different of a game Top Gun is as compared to any other game, and it's one of those shitty faux-mode 7 effect games like G-Loc that just looks absolutely horrible.



    Then I thought about the mirroring! And Voila, it works just fine



    I desoldered the V and soldered the H and now I'm playing Streemerz on my NES!



    Now just to get a little less professional here, this game is fucking great. It is absolutely fantastic, it reminds me of Bionic commando mixed with Cave Story, phenomenal, I definitely have to find the thread that the guy who made this game posted and tell him how awesome he is.



    Once again, thank you everyone for the help! In the end, my original rewiring was correct, I just needed to flip the mirror doohickey.



    [EDIT] I was also going to put, that any noobies who have this same issue and happen to search this, I was going to say that you could also find this out by checking the details file from ReanNES3, however it lists the game Streemerz as having a Vertical mirroring, which is what it was originally set to on my Top Gun cart, 3Gen do you have any idea why that is?
  • ThrashOmenThrashOmen
    And mixed with Hook Champ! I forgot to throw that in there, fantastic iOS game series.
  • removed04092017removed04092017
    Vertical mirroring means H needs to be soldered. Horizontal means V needs soldered. You can check the proof here. SMB scrolls horizontal, so the mirroring is vertical. As you see by the PCB picture, H is set.



    http://bootgod.dyndns.org:7777/profile.php?id=270
  • ThrashOmenThrashOmen
    Hoho then, I guess that sums that up. Thank you for the clarification!
  • LincolnLincoln
    Mirroring still gets me once in a while too, very annoying. And yeah, Streemerz is fantastic. have fun!
  • GorillazeroGorillazero
    Lincoln, you're avatar always makes me laugh.
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