PLEASE, REMEMBER TO UPGRADE THE FIRMWARE, as few bugs were fixed
ACID SRAM PROF MODULE is my next step to help ATARI owners to repair their computers home, as in most of the cases faulty is dynamic ram and upgrade memory to almost massive 8MB !!!!
- Based on small FPGA and quad psram
- 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
- VBXE connector
- EXTRA RAM on board / 64,128,256, 512, 1MB, 4MB, etc..
- configurable with embedded in fpga software - ESC + RESET to enter
- COLD RESET
- FPGA software upgradable via USB_C
- soon more :-)
Inside BOX:
- SRAM MODULE
- mmu adapter
- 4pin wire approx 20cm
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 or send me your ATARI BOARD for installation. Upgrade installation cost is 10 € only. Contact me to arrange installation.
- 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)
- Locate CPU (SALLY, example:CO14806) and MMU inside ATARI
- if Your CPU is socketed - place SRAM MODULE into socket and put CPU back
- if Your MMU is socketed - place MMU MODULE into socket and put MMU back
- Please, be careful! PIN 1 goes to PIN 1
- if mentioned chips are not socketed, desolder them and solder received one into their places
- connect with 4 pin wire MMU ADAPTER with CPU SRAM MODULE !!!
- Connect EXT_SEL pin to ATARI:
SRAM MODULE COMPLETLY REPLACES below parts that can be actually eminated now.
- XE ( and majority of freddy chip, than can be now replaced even with clk_divider built upon TTL 74)
Product gallery
Documentation/Firmware files:
Q: How can i upgrade ACID_SRAMS`s firmware ?
A: Simple. All You need is regular USB-C cable (good quality please!). ACID_SRAM has built in JTAG USB bridge programmer. Do not buy any external programmer! NOT NEEDED !
- connect USB C CABLE to Acid Sram Module and to PC
- disconnect MMU adapter cable
- in device manager new device will be detected.
- Follow manual in order to install drivers and download software: https://lotharek.pl/MANUALS/Gowin_FPGA_PROGRAMMER.pdf
- power on ATARI, ATARI will not start (jtag pins are dual purpose pins - IO function will be disabled)
- Download last firmware from FILES tab and save it to disk
- RESET: before applying PROGRAM BUTTON, atari RESET signalmust be pulled low:
- Atari 800XL - press and hold reset
- ATARI XE - connect THOSE pins and keep connected during programmig
- „Finished, but wakes up failed” is the right communicate at the end.
WARNINGS:
- do not use any usb hubs! direct computer connection only
- use decent shortest possible usb c cables
- due to lack of space in XL machines, USB_C plug must be angled
- disconnect all usb devices, that may interfere with jtagging ( all virtual com ports, other programmers, Arduino/Rasperry stuff, etc.
- to be sure all works, only mice/Keyboards shall be left..
- I know - i am overreacting, but maybe it helps :-)
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