[Coco] HITACHI HD63C09EP

[Steven Hirsch]

On Thu, 4 Aug 2011, gene heskett wrote:

> On Thursday, August 04, 2011 12:29:22 PM Steven Hirsch did opine:
>
>> On Thu, 4 Aug 2011, Mark Marlette wrote:
>>> My last bulk purchase of over 200 pieces from Russia, untested, good
>>> deal.... :)
>>>
>>> Over 50% failure rate.
>>>
>>> I see these quantities are not that high.
>>
>> Will let you know.  I picked a couple up along with some 27C400 16-bit
>> EPROMs (needed for Amiga Kickstart BIOS).  Little ventured, little
>> risked
>
> That is a real find, commies lawyers made that chip disappear when it
> became obvious that their OS3.1 sales were being impacted.  I called the
> chip maker and offered to take the first 50k pieces if they would make
> another run, but they weren't interested.
>
> I had to fix every one of the 10 or so 3.1s kit I bought from commie for
> the tv station, every blessed one of them. I had to read them out in my
> programmer at the station, and re-burn the exact same data into the top
> (otherwise empty) half because commie checks the top of the eprom for valid
> data before it will use it, that is where it gets the exec address from.
>
> The idiots they hired to run their programmer put the file in the bottom
> half of the chip in those machines that were setup for a 2 chip kickstart.

I thought the "official" Commodore ROMs were masked parts.  Sounds like 
yours were EPROMs without a window for the leading "E".

I had to build an adapter board for my Andromeda programmer to handle 
16-bit parts.  Can't say enough good things about this product. 
Inexpensive, well supported and you can buy bare-boards for the (usually 
pricey) personality adapters and fab them yourself.  I originally bought 
it to handle bipolar PROMS.  Price out a commercial unit that handles 
those sometime if you want sticker-shock!

And, yes, I know about the need for double-burning :-) Been there, got the 
T-shirt.

> Now you know "The rest of the story"  ;-)  Be aware that chip seems to have
> a very limited re-programming cycle life.  I lost 2 of them in that rescue
> procedure.  Some of the later ones they shipped were even OTP's, no erase
> window.  My comments on that stupidity were not sharable or printable.  But
> amazingly, I could still burn the top half and use it.  I had a xeltek (sp)
> programmer, could program anything.

There a few vendors on eBay that have brand-new ones from time to time. 
But, I hear your point.  The last used ones I bought had a 20-30% fallout 
rate.  Beggars can't be choosers, since as you point out they are close to 
pure unobtanium.

Steve


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