I have a HLN6046B MLM board which looks like it has the capability to take two 27c512 chips, 8k ram, and 28c64 codeplug. Mine currently only has one 27c512 on it, 2k ram, and 28c16 codeplug. I can find all those pieces parts, but there is another chip which is going to be a 14-pin version of a 74hc153. Can anyone with this MLM board tell me what part number is on that 14 pin chip?
My board currently has v1.13 firmware on it. I want to upgrade it to v6.14, which I have on a later model MLM board.
MLM question
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Re: MLM question
the chip that you probably have on your older MLM board is a 74HC00 (Quad 2-Input NAND Gate) The only one i had to compare was a HLN6143A board, has 40Pins and 2 27C256 with 2K and 28C16. you would have to look at the Board very closely to make shure all the traces run to the correct pins. the HC153 and HC00 are not interchangable but control how the address lines are multiplexed to select the correct chip select and chip enable. there are also jumpers to configure what chips are used, so in a nutshell you could esaly convert a newer pcd (HLN6160B) to work because it is backwards compatable but the older PCB may not have the support for the newer larger Eprom chips. I am in the process of converting some older MLM's to the v6.16 Firmware so i will be able to provide more info as i discover it. there are many people on this board who have done these upgrades before so they can give you better info.