RAM address multiplexer.

FREDDIE is memory decoder and timer. Replaces several chips from the XL line. It takes the address and clock from the CPU and multiplexes it with the appropriate timings and signals to use DYNAMIC memory. FREDDIE also buffers the system clock crystal and divides it down then feeds that to GTIA.

Has nothing to do with bank-switching. That's what EMMU does.

It is used in all XEs and in late XLs (XLFs).

Catalogue numbers

CO61991-29 - NCR
CO61922 - CITEL


Freddie internal schematics (14 KB GIF). Drawn by Jerzy Sobola. . Back (c) 1998-2004 Jindroush Last modified: Tue Feb 13 22:09:08 2001