Atari 400 Installation Instructions Manual

Atari 400 48/52 KB RAM Card
Date: 2018 May 18, version 1.3
Author: Jürgen van Radecke (tfhh)

Introduction

Hi!
Thank you for your purchase of an Atari 400 48/52 KB RAM card. I hope you enjoy this piece of hardware
for our beloved Atari 8-bit computer systems
The Atari 400 48/52 KB RAM card is a replacement for the genuine, made-by-Atari CO61553 add-on card.
This one was only offered by Atari Service facilities and uses 8 pieces of 4164 DRAM (= 64 KB total) and
some TTL chips of the 74s series. Of course the upper 16 KB of 64 KB RAM can´t be used.
The advantages of my card comparing to the original card are:
Uses SRAM instead of DRAM (reducing power consumption, need just +5V, smaller PCB)
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Enables the usage of a very common "little memory expansion" up to 52 KB using the former
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unused area between $C000 and $CFFF
Enables the usage of up to 4 different operating systems installed on an industry standard EPROM
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instead of the special Atari mask-ROMs found on the 400 mainboard
Enables the usage of an operating system which uses the former unused area of $C000-$CFFF
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without modifications to the Atari 400 mainboard
Please read the whole manual completely at least once, even if you´re a professional. The installation of
the Atari 400 48/52 KB RAM card is very easy and only two wires must be soldered. These wires are
needed for detecting an inserted cartridge – otherwise the computer will crash if a cart is inserted.
The Atari 400 48/52 KB RAM card works fine in any Atari 400 computer using PAL or NTSC.
Please check the parts included in the kit:
The Atari 400 48/52 KB RAM card, populated with a 27C256 EPROM
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One ready-to-use crimped connection ribbon cable with 16 pin IDC header and DIL adapter
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All installation instructions are suitable for PAL or NTSC systems.
The default settings of the jumpers on the Atari 400 48/52 KB RAM card are:
48 KB RAM mode
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Operating system chips on the 400 mainboard is used
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Installation Instructions
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