Re: [N8VEM-S100:602] Re: S-100 8086 Up and Running

[Douglas Goodall <douglas...@mac.com>]

Is that bit stuck in every byte?


Http://Goodall.com


On Dec 27, 2011, at 10:33 AM, Bill Lewis <wrl...@gmail.com> wrote:

> I have a TMS 27C512 right now that has a stuck bit that
> won't erase.
> 
> I put the thing in the eraser for 15 minutes.
> Blank check, and all ones except that bit.
> 
> Back in for another 15.  No change.
> 
> And another 20 minutes.  No change.
> 
> Must be kaput.
> 
> 
> On 12/27/2011 10:28 AM, Douglas Goodall wrote:
>> Bill,
>> 
>> Around the same time, I was working at a startup using quite a few
>> 2716's. We were having quite a lot of trouble with them.
>> 
>> I came up with a technique for doing quality assurance on them
>> based on checking the content of the EPROM over time while
>> erasing.
>> 
>> It seems that some cells take longer than others, and the later
>> portions of the erasing time is spent clearing the recalcitrant bits.
>