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MicroMaster MM-8000 microprocessor trainer - bad ROM chip

M

mike_94502

Jan 1, 1970
0
My Elenco MM-8000 microprocessor kit came with a bad ROM chip. After
pulling my hair out for many hours I finally went to an electronics
supply store an purchased a $3 ROM replacement chip, which worked
perfectly.

I'm posting this because others learning digital electronics with this
kit may be affected. The odds of getting a bad chip should be very
low which leads me to suspect Elenco has a bad batch of ROM chips in
their kit. I would hate to see someone give up on their project, like
I almost did, when the problem is really the chip.

The ROM chip is a 24 pin EEPROM. You can replace it with a similar
E2PROM with a part number containing 2816 or some variation. It
should cost $3 to $10.

Overall I like the kit, am learning quite a bit. I guess lesson
number 6.1 in this kit is don't trust anything and don't give up.
 
N

Nickolaus

Jan 1, 1970
0
Hello,
Is it necessary to use anti-static precautions such as
a wrist strap, anti-static pad, and special soldering iron
when building the MM-8000? Or are such precautions
unnecessary in this case? Thank you. Nickolaus
 
R

R. Steve Walz

Jan 1, 1970
0
Nickolaus said:
Hello,
Is it necessary to use anti-static precautions such as
a wrist strap, anti-static pad, and special soldering iron
when building the MM-8000? Or are such precautions
unnecessary in this case? Thank you. Nickolaus
-------------------
Not really, these tools merely enable one to stop thinking.

To do without them:
1) Solder in everything else.

It is safer to use a grounded iron to solder in glue-chips
logic, if you do solder them, but it is quite likely to work
fine anyway.


2) Solder in sockets, then when all soldering is done, ground
yourself to the device ground, and then without moving, ground
yourself to the static foam of the processor and EPROM and then
remove them from the foam and carefully plug them in, making
certain all pins go in properly. With your body at the same
relative potential as the ground and the foam or antistat
container they come in, they are safe.

-Steve
 
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