64k SRAM Module for XL/XE computers (v3)

FROM LOTHAREK'S WEB SITE:

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
• Ultimate 1MB connector
• VBXE IRQ connector
• CRUCIAL for RAPIDUS installation ...in major cases :-) (2022-02-10)

Inside BOX:

• SRAM MODULE

Disclaimer: 

• If you:
  • are not familiar with soldering
  • do not have proper tools
  • do not understand STEP BY STEP instructions 

          please LET a pro technician do it for you

• Please remeber - wrong tools usage or low skills may damage atari 
• Any damage / harm to your hardware is NOT subject of any kind of warranty.
• Installation is very easy, but unexperienced hands can do a lot of damage. Please, do not ask me questions WHAT HAVE I DONE WRONG WITH INSTALLATION - answer will be always the same -

I DO NOT KNOW

Step by step: 

• REMOVE old RAM CHIPS ( hint: not necessary actaully; if Your ram do not get hot, You can remove resistors on data lines to ram and keep ram chips intact) 
• install  SRAM MODULE under MAIN CPU; insert CPU to SRAM MODULE
• Please, refer first to VBXE fitting manual to locate following signals at Your motherboard:
  • EXTSEL (EXT solder point at SRAM module)
  • CasInh (CI solder point at SRAM module)
• Make at least ONE CONNECTION between CI point  at sram module  to  CAS_INHIBIT SIGNAL at ATARI board
• EXT /Extension Select - EXTSEL signal/  is not needed to resurect atari, but some upgrades may needed it, especially all PBIs:  Rapidus, VBXE with RAM cores, etc....
• PIN 1 is below EXT hole; bottom left at below picture.

ps. 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 COMPLETLY REPLACES below parts that can be actually eminated now. 

• 800XL

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