Data I/O Series 22 EPROM Programmer help

[Allison]

>
>Subject: Re: Data I/O Series 22 EPROM Programmer help
>   From: "Ethan Dicks" <ethan.dicks at gmail.com>
>   Date: Fri, 16 Jun 2006 13:59:04 +1200
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 6/14/06, Roy J. Tellason <rtellason at verizon.net> wrote:
>> We used to do a LOT of c64 repairs way back when,  and every one of those
>> beasts had a "906114" PLA in it that as I understand it was an 82S100 part.
>> And it was a very common failure item,  resulting more often than not in a
>> blank screen or perhaps some bizarre display.
>
>Right... it's the address bus manager, among other things.  When it
>fails, the CPU can't get to RAM or ROM or the VIC-II, typically.
>
>> Any idea as to why that should fail so often?
>
>Thermal death?  It's a bi-polar part, not *MOS, and it does run hotter
>than the rest of the components.

It's bipolar and also programable (fuseable links) and they do have
a tendancy to develop shorted paths where they were once "opened".


Allison

>
>-ethan