MMU

## Description

Selects cartridge banks, hw chips, osrom, BASIC rom. In older machines had no Atari number, was PAL16L8.

## Catalogue numbers

    CO60609 (1200/1400)
    CO61618 (XL/XE)
    C101686 (XEGS) = 16L8

## Pinout (CO61618)

/MAP | IN from PB7 - low selftest on, hi selftest off
RD4 | IN from cartridge port
RD5 | IN from cartridge port
REN | IN from PB0 - low OS off, hi OS on
/REF | IN refresh
/S5 | OUT cart bank select
/BASIC | OUT basic rom chip select
/MPD | IN MPD PBI
/OS | OUT OS rom chip select
/CI | OUT CAS inhibit
/IO | OUT goes to 74LS138, selects hw chips (Y0 - GTIA, Y2 - POKEY, Y3 - PIA, Y5 - CCTL)
/BE | IN from PB1 - low BASIC in, hi BASIC out
/S4 | OUT cart bank select

Here is PAL (2 KB SRC) source by Bob Woolley and GAL (0 KB SRC) source from Erhard Puetz. I didn't check them for correctness (which means nothing... :) Back (c) 1998-2004 Jindroush Last modified: Mon Jun 3 22:49:10 2002