I thank my dear friend that gave me the Spem EXP-MEM 512k.
Various companies offered to upgrade your QL with an internal memory upgrade. This was normally 512K, but some companies also offered a 256K version.
The method of upgrade was in two ways:
- Removal of the existing QL memory chips and replacement to give a total of 512K
- An internal board, which connects to the 8301 ULA socket, and has a wire to the 68008 processor.
The downside of this method of upgrading the QL’s memory was:
- The memory access was slower than external memory
- You could not use some of the later QL expansions, such as the Trump Card which themselves had memory built into the interface.
Internal interfaces were advertised by a range of companies, including CST, MicroPeripherals and Silicon Express.
source: Sinclair QL Computer Wiki