Rambo 3 - Main CPU Program Confusion

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    • Rambo 3 - Main CPU Program Confusion

      I've been sitting around with a poor Rambo 3 pcb that has been used as a donor few times, finally, after a very long time, i was able to give him back the guts.
      When i was trying to check what was already on it, the confusion begins in the main CPU eeprom code.
      I compared the 2 27c010 (B-11 and B-14) with no problem, figuring mine was a Eu version of the game.
      Then i went to check B93-06 and B93-07 and the confusion begins.

      As many of this boards they came with original proms, 28dip, at first i usually thought was a classic 27512 64kbx8, more like the same eeprom located for the sound cpu (B93-10 @ic36), but, i couldn't find them in the rom set.

      B93-07 is located at mark ROM1E
      B93-06 is located at mark ROM1O

      So, if these were 27512 i must soppose to find them in the 64kb rom compartment. And they are not there!

      64kb files in the (main rambo3p) rom set are: r3.00, r3.0e and r3.0o (last is ramb-10, the 27512 sound code, wich match as mine)

      I tryed to compared all of them (why 3??) and none have a match.
      Then i saw there were actually some files called 1E and 1O (and ramb3-06/ramb3-07), exaclty was i just trying to search... but they are 128kb files! so these are for 27c010 eeproms.

      So then i though to just see if in those files there was a match for them, and they actually do in most parts. Obviously, as i was comparing a 64kb file to a 128kb file, there was a huge empty gap between them, since the dump was half the file.

      So what the hell i'm missing here?
      I look at all of the picture i was able to find on google, seems that my board is the same as all of the others (the CE wire patch underneath too).
      I don't have any idea if these proms (considering they are taito) are good or not, and why i cannot find the 64kb code in these location. I hardly believe that these 28pin proms are 128kb (i have never seen that)
      I'm soo confused on this... ?(
    • caius wrote:

      They are 28 pin 1Mbit MASK ROMs with non-JEDEC pinout.You can replace them with adapted 27C1000/27C301 (or also 27C010 but more modifications are needed to swap pin 2 and pin 24).Otherwise you can buy adapters I made with TSSOP flash ROMs.
      Ha.. i didn't even payed attention to the silkscreen. I've never seen these or came across until now.
      Never thought about a reply from you neither, anyway, thank you for the explanation.
      How's your sea view? Still good?