The OScard was supplied by Quest Automation Ltd and supplied the necessary memory switch and RAM capacity required in order to run their CPM 68K Operating System. The card pictured in their adverts is marked 'MPC Module' (Issue A) - however, we have also seen a similar looking card called 'OS Module' (Issue C) - so it is uncertain if these provided different functions or were one and the same (Quest never advertised an MPC Module so far as we know.

The OSCard only appears to contain a 1K RAM chip, plus lots of glue logic:

  • 7805 voltage regulator
  • 74LS133 13-input NAND gate
  • 74LS14 hex Schmitt trigger inverter
  • 74LS14 hex Schmitt trigger inverter
  • 7416 hex inverter buffer/driver with 15 V open collector outputs
  • 74LS133 13-input NAND gate
  • MOSTEK MK4801AN / MK4118A 1k x 8 SRAM
  • 74LS14 hex Schmitt trigger inverter
  • SN74LS74AN: Dual D Type Flip Flop
  • 74LS14 hex Schmitt trigger inverter
  • 74LS32 quad 2-input OR gate

The OScard could be used on its own (allowing you to run CP/M-68K from microdrive cartridge), or came pre-fitted inside the Quest Floppy Disk Drive interface.

Interestingly it appears to allow the CPM 68K Operating System to share some QDOS routines and facilities rather than re-writing the whole operating system.

Quest Automation OSCard Title: OScard
Interface Type: Memory Manager
Connection: Sinclair QL Expansion Bus
Through-Connector: No
Manufacturer: Quest Automation Ltd
Year First Sold: 1984
Original Price: £49.50
Reviews: Unknown
Download Manual: Unknown
Accompanying Software: None

  • qlwiki/oscard.txt
  • Last modified: 2017/09/04 09:53
  • (external edit)