I have an Atari 520 STFM and wanted to upgrade it to 1mb. The motherboard is a C103175 Rev 1, looking around the internet I found references to the 1040 STF but nothing about 520 STFM version.
I read up on what to do but I still have a few questions...
- The memory chips are d424256c-12 but they are difficult to find, can I use different speed chips like d424256c-10 or d424256c-70?
- When upgrading to 1mb, I understand I need to be solder resistors in R71, R72 and R73... But they are already there?
- I also need to be solder capacitor in C25, C26, C27 and C28... But again they are already there?
- Is there anything else i need to do other than just solder new chips in?
Thanks in advance