NSC 8477 Was: New takes on XT-IDE, a new FDC, and a new CM/S GAL

[Chuck Guzis]

On 12/19/18 5:38 PM, Ali via cctalk wrote:
>> Micro Solutions initially shipped the CompatiCard IV with the Intel
>> chip--and it worked well.  Intel then revised the chip as the 82077AA-1
>> to add tape support and broke the FM capability.  When I inquired about
>> this to Intel, I got the response "Who uses FM anymore?".   Micro
>> Solutions sent a bunch of retrofit kits with NSC chips in them to a
>> small bunch of CC IV purchasers after they discovered the problem.
>> Fortunately, the 8477 is pin-compatible with the 82077.
> 
> Chuck,
> 
> Are you saying that CCIV initially had an NSC 8477 or an 8473? Or that it had an Intel chip and when Intel came out with a new revision they went to an NSC chip? Also are all CCIVs retrofitable? i.e. can I order an NSC chip and plop it into my CCIV to get FM back? Finally can you drop in an NSC 8473 in a CCIV to get 128-byte MFM or the best you can do is switch to a NSC 8477? TIA!

No, the CCIV initially had a plain-jane Intel rev 0 82077AA in a 68 pin
PLCC.  After Intel "improved" the chip to the 82077AA-1, FM ceased to
work.  Fortunately, as I mentioned NSC 8477 is a plug-in replacement,
with the exception of not needing an extra external cap (the pin is NC
on the National chip).

--Chuck