Is it put a switch on the A12 line? So A12 selected the chip is set "high" then upper region will be read, otherwise lower bank will be read?Ģ) Add a 28 pin socket into 6J with pins 1, 2, 27, & 28 exposed. How do I setup switch on EPROM 64kb for switch between mspacman 5-row roms in first 32kb bank to pacman 5-row roms in second bank of higher 32kb in the 64kb chip? What is meant by "8th finger" and "bottom component"? So does my A12 connect then to 7N? What must connect to 6B? Why I need connection to 6B?ĦB pin 5 (test connector 8th "finger" from the bottom component side) So below A14 is connected to 7N but if I do use a 2764 type EPROM I do not have a A14 at all. So where must A12 go for 64kb chip becuase that is the highest A-pin that can be selected to initiate the higher bank of RAM. Now the problem I face is in the example of 512kb the chip do have A13,A14,A15 extra.
#MS PACMAN GAME ROM MANUAL#
Why I am cautious is in this manual page 35, it describe that EPROM banks are in tri-state mode. Once working then to split to have the firstģ2kb filled with 8 times 4kB of 6F Normal speed and upper 32kB fast speed of 6F. I probably copy 6F (normal speed) multiple times to fill lower and higher ram area. Just plain copy of 6F into At28C64(2764).ī) Then thereafter do replace 5E & 5F with a 2764 type EPROMĬ) Then if all is working then play around with put in a switch between mspacman vs pacman 5e/5f row byįilling in 5E and 5F of mspac in lower bank of first 32kb of ram and pacman 5E & 5F in upper 32kb bank of ram. GOTO to section: "Converting a PacMan board to Ms.Pacman using two EPROM's, and Two Game Pacman Hack."Ī) I only want to replace 6F with 64kb EPROM 28pin and just map to correct pins using the "principles" of the above but not a multi EPROM with a switch as the multi pac mod. The problem is which pin A12 need to map if I do use a 64kb type chip and not a 512kb. The above mentioned page do explain to map 512kb EPROM with multi rom in one EPROM. To replace the 6F with 2764 kind of EPROm I need to map the correct pins. I have bought a small EPROM programmer (only one in SA) that can write AT28C64 (64kb).
To replace I have asked my brother in USA to buy the ROMS and will brought it to South Africa My ROM 6F is faulty and also maybe 5E and 5F. My aim is to play a perfect pacman this year and get a good run on mspacman in upper range between 700K and killscreen this year - all normal speed.įirst I want to fix mspacman PCb just to run normally then change it to switch to pacman.
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