Commodore Amiga A500 Technical Reference Manual page 165

Section 5
Amiga Hard DisWSCSl Controller
DESCRIFT"I'ON
The Amiga Hard DisWSCSl Controller is an intelligent high perfor-
mance controller designed t o interface both ST506 hard disk drives
and SCSl devices t o the Amiga expansion bus architecture. A back-
ground command processor provides high level command interpre-
tation minimizing Host intervention. Data is transferred t o and from
the Host via DMA (direct memory access) with FlFO allowing high
data throughput while maintaining reasonable bus bandwidth for
other bus controllers.
FEATURES
Support for up t o two ST506 hard disk drives
Full SCSl with Maclntosh Plus compatibility
High level command interpretation and exceptional handling per-
formed by 280 processor
Support for up t o 8 heads, 2 0 4 8 cylinder with 51 2 byteslsector
Individually Programmable Drive Characteristics
1 :l sector interleave
3 2 bit ECC for data correction
Multiple block transfers
Full auto-config compatibility
Real time data transfer rates of up t o 800nslbyte via DMA
SPECIFICATIONS 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:
MFM
Up t o 2 0 4 8
Up t o 17
51 2
8
2
3.2 us t o 6.5 ms
5.0 MbitJsec.
1 2 nanosec.
1 :l
1 :2
3 2 bits
1
l
bits