[Coco] disk controller chip

[Frank Swygert]

Date: Mon, 5 May 2014 09:19:47 -0600
From: Darren A<mechacoco at gmail.com>

The first controller (26-3022) requires a 12V supply and uses a WD1793 
chip. The second generation (26-3029) comes in two flavors, with the 
earlier ones having an MB8877 and the later ones having a WD1773. The 
FD-500, FD-501 and FD-502 all use the WD1773. In the FD-502 the chip is 
not socketed making it much more of a pain to replace.

==========================

Note that the MB8877 and WD1773 are pin compatible -- they can be 
swapped. The MB8877 is a "work alike" of the WD1773 made by another 
company, I assume under license but could have been reverse engineered.

-- 
Frank Swygert
Editor - American Motors Cars Magazine
www.amc-mag.com