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MAXIMIZER troubleshootung

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  by Bill Degnan - 02/23/2022 23:28
This Sigma Designs MAXIMIZER Multi board was failing to POST at the 384K mark. I removed the board to allow the 3270 PC to boot, but the software installed in the system requires more than the 256K found in the motherboard. So, I need troubleshoot/ fix the board. I tested all AM9064 RAM chips.

I found 5 bad RAM chips. I moved the good chips into banks 0 through 4, and set the SW2 switches to 320K (5x64=320). I set aside the 5 bad chips. Hopefully 576K (256+320) will be enough to run MS Word and the other contemporary software installed on the hard drive. Id like to see the primitive version of Word as most computers of this era used WordPerfect. The OS is IBM DOS 3.3, meaning the system DOS was upgraded in 1987 or 88. Bank 5 is now completely empty of RAM chips. I believe you need a full bank, meaning I cant use the four remaining good chips. The MAXIMIZER reference guide is found here: https://stason.org/TULARC/pc/io-cards/S-T/SIGMA-DESIGNS-INC-Multi-I-O-MAXIMIZER.html.

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