Re: [N8VEM-S100:604] Re: S-100 8086 Up and Running

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

Yea, you have a fifty-fifty chance of the prom being ok even if your data load takes up the entire prom. You can always program around it. :-)

Http://Goodall.com


On Dec 27, 2011, at 11:35 AM, Bill Lewis <wrl...@gmail.com> wrote:

> On 12/27/2011 2:31 PM, Douglas Goodall wrote:
>> Is that bit stuck in every byte?
> 
> No, just that one bit in the entire EPROM.
> 
> Luckily the current data load has that bit clear, so
> I haven't thrown it out yet.
> 
> Bill
> 
>> 
>> 
>> 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.
>>> 
>