Amiga Hardware Database Expansion cards



SCRAM 2000 Software
Company
Norman Jackson / MegaMicro, Australia
 Amiga
A2000, A3000, A4000
 Interface
Zorro II
 Autoconfig ID
4096 / 3,4
  • SCSI + RAM for A2000, a public domain kitware project
  • schematics, building instructions and driver software are all published
  • custom logic (GALs, PALs, etc.) are not published, these chips have to be ordered from the author
  • the five custom logic chips:
    • Bertie - controls the memory autoconfigure logic
    • Cyril - SCSI autoboot controller chip
    • Griswold - master timing controller for the DRAMs
    • Ronald - controls RAM operation
    • Dennis - main address decoder
    SCSI controller
  • provides sockets for either an 8 or 16 bit SCSI controller IC:
    • National Semiconductor DP8490V - an enhanced version of NCR 53C80
    • NCR 53C94 - the card performs 50% faster with it
  • the two controllers require different custom logic chips and autoboot ROM
  • autoboot ROM - autobooting requires Kickstart 1.3
  • autoboot disable switch for older Kickstarts or for game compatibility
  • supports the Rigid Disk Block standard
  • place for a 3.5" hard disk on the card
  • hard disk power connector
  • 50 pin internal SCSI header
  • external DB25 SCSI connector
  • SCSI access LED connector
  • termination power option - jumper selectable +5V on pin 25 of the external connector and pin 26 of the internal header for using passive terminators
  • non-DMA transfer
  • custom synchronising logic
    memory
  • 16 ZIP sockets accept up to 8 MB RAM
  • takes 256k×4 or 1M×4 ZIPs
  • ZIP sizes cannot be mixed
  • possible configurations are 0, 2, 4 or 8 MB
  • static column ZIPs work, but not improve performance
  • zero wait state
  • RAM access LED
  • autoconfigure LED




About Search Links