SRAM 64Kb REVISED V3

Description

Memory and Delay Line Replacement for Atari 8-bit computers.

SRAM MODULE is my first step to help ATARI owners to repair their computers home, as in most of the cases  faulty is dynamic ram

• replaces base ram of 64KB in all 8bit ATARI
• replaces broken DELAY LINE chip in XL computers and many more ICs – refer to schematics down the page
• upgrades ram in 600XL to 64KB
• PCB thickness is 0,8mm

Step by step: 

• REMOVE old RAM CHIPS ( hint: not necessary actually; if your ram does not get hot, you can remove resistors on data lines to ram and keep ram chips intact)
• install  SRAM MODULE under the MAIN CPU; insert CPU to SRAM MODULE
• Connect CI point at SRAM module  to  CAS_INHIBIT SIGNAL (for example MMU pin 16)
• EXT – connection to Extension Select is not needed to resurrect Atari, but some upgrades may be needed: Rapidus or connected to PBI.  Please, refer to the schematic of your computer.
• PIN 1 is below EXT hole; bottom left at below picture.

Hint – A handy article https://www.evilmadscientist.com/2010/basics-finding-pin-1/ if you do not know how to identify pin 1 in chips. PIN 1 always goes to Pin 1

SRAM MODULE COMPLETELY REPLACES the below parts that can be actually eliminated now. 

 

• 800XL

 

• XE ( and the majority of Freddy chip, they can be now  replaced even with clk_divider built upon TTL 74)

Disclaimer: 

• If you are not familiar with soldering do not have proper tools or do not understand STEP BY STEP instructions please LET a pro technician do it for you.
• Please remember – wrong tool usage or low skills may damage Atari.
• Any damage/harm to your hardware is NOT subject to any kind of warranty.
• Installation is very easy, but inexperienced hands can do a lot of damage.