ACID SRAM Lite

ACID SRAM Lite is the first step to help ATARI owners to repair their computers at home, as in most of the cases dynamic RAM is faulty.

FEATURES:

• Based on small FPGA and quad PSRAM
• Replaces base 64KB RAM in all 8-bit Ataris
• Expands RAM to 128KB / 192KB / 256KB / 320KB (PORTB)
• Replaces broken DELAY LINE chip in XL computers and many more ICs - refer to schematics below
• Upgrades RAM in Atari 600XL to 64KB
• PCB thickness is 0.8mm
• Ultimate 1MB connector
• VBXE connector

IN THE BOX

• ACID SRAM Lite module

Disclaimer: 

If you are not familiar with soldering or you do not have proper tools, we can install the expansion for you. Please contact us to arrange installation.

If you are installing the device yourself, we will not take any responsibility for any damage to your hardware and the device will NOT be subject of any kind of warranty.

Step by step: 

• Remove old RAM chips (hint: this is actually not necessary; if your RAM chips do not get hot, you can remove resistors on data lines to RAM and keep chips intact) 
• Install SRAM module in place of main CPU. Pin 1 of the SRAM module is at the bottom left on the picture.
  
• Insert CPU to SRAM module
• Please refer to VBXE fitting manual to locate following signals on your motherboard:
  • EXTSEL (EXT solder point on the SRAM module)
  • CasInh (CI solder point on the SRAM module)
• Make at least one connection between CI point on the SRAM module  to  CAS_INHIBIT signal on Atari motherboard
• EXT / Extension Select - EXTSEL signal is not needed to boot up the Atari, but some upgrades may needed it, especially all PBIs connected expansions: Rapidus, VBXE with RAM cores, etc
• Set jumpers for extended memory as follows (default is 320Rambo):
  

  JP1	JP2	JP3	MODE
  ON	OFF	OFF	65XE/800XL/600XL (only base memory)
  OFF	ON	OFF	130XE (ext. 64k CPU / 64k ANTIC)
  ON	ON	OFF	192XT (ext. 192k CPU / 64k ANTIC)
  OFF	OFF	ON	256XE (ext. 192k CPU+ANTIC)
  ON	OFF	ON	256NI (ext. 192k CPU+ANTIC + base memory mapped to $4000)
  OFF	ON	ON	320Rambo (ext. 256k CPU+ANTIC)

SRAM module completely replaces below parts that can be actually eliminated now. 

• 800XL

• XE (and majority of FREDDIE chip, than can be now  replaced even with CLK_DIVIDER ilt upon TTL 74)