Section 5 Amiga Hard Disk/Scsi Controller - Commodore Amiga A500 Technical Reference Manual

Amiga Hard Disk/SCSI Controller
DESCRIPTION
SPECIFICATIONS
The Amiga Hard Disk/SCSI Controller is an intelligent high perfor-
mance controller designed to interface both ST506 hard disk drives
and SCSI devices to the Amiga expansion bus architecture. A back-
ground command processor provides high level command interpre-
tation minimizing Host intervention. Data is transferred to and from
the Host via DMA (direct memory access) with FIFO allowing high
data throughput while maintaining reasonable bus bandwidth for
other bus controllers.
FEATURES
●
Support for up to two ST506 hard disk drives
● Full SCSI with Macintosh Plus compatibility
● High level command interpretation and exceptional handling per-
formed by Z80 processor
●
Support for up to 8 heads, 2048 cylinder with 512 bytes/sector
Individually Programmable Drive Characteristics
●
1:1 sector interleave
●
32 bit ECC for data correction
●
Multiple block transfers Full auto-config compatibility
●
Real time data transfer rates of up to 800ns/byte via DMA
Performance
Hard Disk (ST506)
Encoding method:
Cylinder per head:
Sectors per track:
Sector length:
Heads:
Drive Selects:
Step Rate:
Data Transfer Rate:
Write Precomp Time:
Sector Interleave:
Sector Interleave Across Heads:
Ecc Polynomial:
Burst Error Correction:
159
Section 5
MFM
Up to 2048
Up to 17
512
8
2
3.2 us to 6.5 ms
5.0 Mbit/sec.
12 nanosec.
1:1
1:2
32 bits
11 bits