Heron 4MB_70523

Heron 4MB is RAM expansion for Atari ST / STM / STF / STFM / Mega ST. It was designed by Bartek Swiderski and is manufactured by Lotharek.

Please note: there are few versions of this expansion designed for different revisions of Atari ST motherboard. This will work only with motherboards marked C070523-001. Please check what motherboard revision you have before purchasing.

Available versions of Heron 4MB:

• Heron 4MB_70789 - for Atari ST with motherboard marked C070789-001
• Heron 4MB_70523 - for Atari ST with motherboard marked C070523-001
• Heron 4MB_70859 - for Atari ST with motherboard marked C070859-001 (adapter in development)
• Heron 4MB_03414 - for Atari ST with motherboard marked C103414-001 (adapter in development)
• Heron 4MB_UNIVERSAL - for Atari ST motherboards not listed above and with socketed MMU

Heron RAM expansion board offers 16 MB RAM. Due to the hardware limitation of the memory management system offered by the original MMU chip, Atari ST can only use 4 MB. However after replacing the MMU with RemakeMMU (in development) one will have 10 MB (Mega ST) or even 14 MB RAM. 

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.

Installation instruction (please refer to detailed instruction available in Downloads tab above)

• Remove Shifter from its socket (or desolder it and install new precision DIP socket)
• Insert Heron's main PCB in place of Shifter chip - be careful with orientation
  
• Insert Shifter back into Heron's top socket
• Desolder resistors on the motherboard as per installation manual
• Disable built in RAM using 4k7 resistors (RAS0 and RAS1 signals)
• Solder second PCB in place of resistors
• Connect two wires to WE and A9 signals
• Connect both PCBs with supplied ZIF cable (you must see blue tabs)
  
• Ready :-)

Inside the box:

• Heron 4MB main PCB
• C070523-001 adapter
• 20cm ZIF cable