Amiga Storage Peripherals


SCRAM 500

> Company: Norman Jackson / MegaMicro, Australia
> Date:
> Amiga: A500
> Interface: side expansion port
> Autoconfig ID: ID4096 / 3,4

Features
SCSI + RAM For A500, 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 Four Custom Logic Chips:
Bertie – Controls The Memory Autoconfigure Logic
Cyril – 8 Bit SCSI Autoboot Controller Chip
Griswold – Master Timing Controller For The DRAMs
Humphrey – Controls RAM Operation

SCSI Controller
National Semiconductor DP8490V SCSI Controller IC – An Enhanced Version Of NCR 53C80
Autoboot ROM – Autobooting Requires Kickstart 1.3
Autoboot Disable Switch For Older Kickstarts Or For Game Compatibility
Supports The Rigid Disk Block Standard
External DB25 SCSI Connector
SCSI Access LED
Termination Power Option – Jumper Selectable +5V On Pin 25 For Using Passive Terminator
Non-DMA Transfer
Custom Synchronising Logic

Memory
16 ZIP Sockets Accept Up To 8 MB RAM
Takes 256kx4 Or 1Mx4 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

Notes
Connects To The Side Expansion Port
Passthrough Connector Is Optional
The Case Is Wide Enough For A Companion Board, The SCRAM-Jet – A 030 Accelerator With 32 Bit RAM, But It Was Never Published
Works With The A1000