MEK6800D2 restoration

Wim wim at hackbox.be
Wed Nov 17 19:33:26 CST 2010


I'm in the process of restoring a Motorola MEK-6800-D2 evaluation kit.

The kit was adapted and has its RAM on a separate board through an 
EXORciser backplane.

After putting everything together and verifying that all looks good, 
I've applied +5V from an ATX power supply.  The '-' prompt appeared, the 
JBUG monitor program is working and I even dumped the ROM and some 
EPROMs over the cassette port and decoded them on a PC :)

So far so good, but to do anything cool I need the RAM board going.  The 
problem is that this (custom wire-wrapped board) is using 16 MCM4116 
chips. They need also -5V and +12V. Ok, these are available on the ATX 
power supply but I'm affraid of doing anything stupid that might blow up 
something.

What would you check before applying these additional power levels ?

I've been verifying a bit with an ohm meter that the -5V and +12V leads 
are not by accident connected to anything they shouldn't but not sure if 
that's a good way.

I also read in the datasheet that you need to apply -5V before the 
others and removing it after the others. How would you do that ? I was 
thinking on having the -5V and GND permanently connected. So after 
switching on the power supply it will have -5V right away. Then manually 
connect a additional cable having GND, +5V and +12V.  On power off do 
the reverse. Is that a good idea ? Not very handy but if it works I'll 
live with it.

Thanks for any advice,

Wim.
-- 
hackbox dot be slash museum




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