Difference between revisions of "Storage"

From Vogons Wiki
Jump to: navigation, search
(→‎IDE and BIOS Limits & Incompatibilities)
(→‎IDE and BIOS Limits & Incompatibilities)
Line 27: Line 27:
  
 
===IDE and BIOS Limits & Incompatibilities ===
 
===IDE and BIOS Limits & Incompatibilities ===
−
* 528 MB limit - BIOS before '''July 1994''' rarely support drives over 528MB (ATA0 Heads <= 16, BIOS Sectors <= 63, BIOS Cylinders <= 1024 )
+
* 528 MB limit - BIOS before '''July 1994''' rarely support drives over 528MB (Cylinders <= 1024 (BIOS), Heads <= 16 (ATA0), Sectors <= 63 (BIOS))
 
* 2015 MB limit - BIOS before '''May 1996''' rarely support drives larger than 2015 MB ( BIOS cylinder values <= 4095 )
 
* 2015 MB limit - BIOS before '''May 1996''' rarely support drives larger than 2015 MB ( BIOS cylinder values <= 4095 )
 
* 3277 MB limit - Phoenix BIOS 4.03 and 4.04 lock when a drive is configured with a capacity over 3277 MB.  
 
* 3277 MB limit - Phoenix BIOS 4.03 and 4.04 lock when a drive is configured with a capacity over 3277 MB.  
 
* 4.2 GB limit - BIOS before '''February 1997''' have the first ECHS (Extended CHS) limit.  DOS and Windows 95/98 cannot handle 256 heads.  'Large' mode in the BIOS produces an alternate geometry by doubling the number of heads and halving the number of cylinders shown to DOS to keep the cylinders below 1024. This method stops working at 4032 MB (1024 cylinders, 128 heads, 63 sectors) if the drive reports 16 heads.
 
* 4.2 GB limit - BIOS before '''February 1997''' have the first ECHS (Extended CHS) limit.  DOS and Windows 95/98 cannot handle 256 heads.  'Large' mode in the BIOS produces an alternate geometry by doubling the number of heads and halving the number of cylinders shown to DOS to keep the cylinders below 1024. This method stops working at 4032 MB (1024 cylinders, 128 heads, 63 sectors) if the drive reports 16 heads.
−
* 7.9 GB limit - Other BIOS from this period had a Revised ECHS limit.  'Large' mode in the BIOS by presenting an alternate geometry using multiples of 15 heads so that 240 heads can be presented as the max alternate geometry.  This method stops working at 7560 MB (1024 cylinders, 240 heads, 63 sectors)
+
* 7.9 GB limit - Other BIOS from this period had a Revised ECHS limit.  'Large' mode in the BIOS by presenting an alternate geometry using multiples of 15 heads so that 240 heads can be presented as the max alternate geometry.  This method stops working at 7560 MB (C=1024, H=240, S=63)
−
* 8.4 GB limit - Final CHS limit - Bios geometry translation uses heads as the lowest value in the sequence 16, 32, 64, 128, 255 to present an alternate geometry up to (1024 cylinders, 255 heads, 63 sectors).  Hard drives oarger than 8.4GB report a geometry of 16383,16,63 to indicate  that they are larger than CHS
+
* 8.4 GB limit - Final CHS limit - Bios geometry translation uses heads as the lowest value in the sequence 16, 32, 64, 128, 255 to present an alternate geometry up to (C=1024, H=255, S=63).  Hard drives larger than 8.4GB report a geometry of C=16383,H=16,S=63 to indicate  that they are larger than CHS
 
* 33.8 GB limit - BIOS before '''August 1999''' often stored the cylinders as a 16 bit value, so the max cylinders was 65535
 
* 33.8 GB limit - BIOS before '''August 1999''' often stored the cylinders as a 16 bit value, so the max cylinders was 65535
 
* 137.4 GB limit - BIOS before '''September 2001''' only used ATA-5, which used 28 bits to identify each LBA sector, limiting drive capacity to 137GB.  ATA-6 extended this to 48 bits.  Hard drives over 137.4 GB should report an LBA capacity of 0xfffffff sectors and report the actual value in the 48-bit field.
 
* 137.4 GB limit - BIOS before '''September 2001''' only used ATA-5, which used 28 bits to identify each LBA sector, limiting drive capacity to 137GB.  ATA-6 extended this to 48 bits.  Hard drives over 137.4 GB should report an LBA capacity of 0xfffffff sectors and report the actual value in the 48-bit field.

Revision as of 00:12, 22 March 2021

What controller will you use?

ISA IDE

  • 16bit ISA controllers, common before 1995, that essentially connected IDE storage directly to the ISA bus
  • Interface is slow enough that all storage built since 1995 connected to it will have similar performance
  • Modern storage is very compatible with these adapters
  • 528MB limit - BIOS before July 1994 rarely support drives over 528MB (IDE Heads <= 16, BIOS Sectors <= 63, BIOS Cylinders <= 1024 )

Early EIDE

  • Common between 1993-1996
  • Mid to Late 486
  • VLB without BIOS support
  • 528MB limit - BIOS before July 1994 rarely support drives over 528MB (IDE Heads <= 16, BIOS Sectors <= 63, BIOS Cylinders <= 1024 )
  • 2GB limit - BIOS before May 1996 rarely support drives larger than 2015 MB ( BIOS cylinder values <= 4095 )
  • Phoenix BIOS 4.03 and 4.04 lock when a drive is configured with a capacity over 3277 MB.

Changing ATA (ATA-33 & ATA-66)

  • Common between 1995-1998
  • Late 486 and Pentium Socket 7 systems
  • 2GB limit - BIOS before May 1996 rarely support drives larger than 2015 MB ( BIOS cylinder values <= 4095 )
  • 8GB limit - DOS and Windows 95/98 are limited to 255 Heads.

Mature ATA (ATA-100 & ATA-133)

  • Common between 1999-2010
  • Little performance difference between the two protocols
  • Require connection to the CPU faster PCI to reach full potential
  • BIOS before 2002 rarely supports 128GB drives

Sata IDE


IDE and BIOS Limits & Incompatibilities

  • 528 MB limit - BIOS before July 1994 rarely support drives over 528MB (Cylinders <= 1024 (BIOS), Heads <= 16 (ATA0), Sectors <= 63 (BIOS))
  • 2015 MB limit - BIOS before May 1996 rarely support drives larger than 2015 MB ( BIOS cylinder values <= 4095 )
  • 3277 MB limit - Phoenix BIOS 4.03 and 4.04 lock when a drive is configured with a capacity over 3277 MB.
  • 4.2 GB limit - BIOS before February 1997 have the first ECHS (Extended CHS) limit. DOS and Windows 95/98 cannot handle 256 heads. 'Large' mode in the BIOS produces an alternate geometry by doubling the number of heads and halving the number of cylinders shown to DOS to keep the cylinders below 1024. This method stops working at 4032 MB (1024 cylinders, 128 heads, 63 sectors) if the drive reports 16 heads.
  • 7.9 GB limit - Other BIOS from this period had a Revised ECHS limit. 'Large' mode in the BIOS by presenting an alternate geometry using multiples of 15 heads so that 240 heads can be presented as the max alternate geometry. This method stops working at 7560 MB (C=1024, H=240, S=63)
  • 8.4 GB limit - Final CHS limit - Bios geometry translation uses heads as the lowest value in the sequence 16, 32, 64, 128, 255 to present an alternate geometry up to (C=1024, H=255, S=63). Hard drives larger than 8.4GB report a geometry of C=16383,H=16,S=63 to indicate that they are larger than CHS
  • 33.8 GB limit - BIOS before August 1999 often stored the cylinders as a 16 bit value, so the max cylinders was 65535
  • 137.4 GB limit - BIOS before September 2001 only used ATA-5, which used 28 bits to identify each LBA sector, limiting drive capacity to 137GB. ATA-6 extended this to 48 bits. Hard drives over 137.4 GB should report an LBA capacity of 0xfffffff sectors and report the actual value in the 48-bit field.
  • Early IDE drives do not always work correctly with mature LBA controllers and must be manually set to 'CHS' mode in order to operate correctly.

Modern Storage for Retro Computers

SD to IDE Pros

  • SD Cards are cheap
  • Quick response on small reads and writes

CF (Compact Flash) Pata DOM (Disk on Module) Sata Drive mSata M2 Sata USB to IDE Sata SSD Sata DOM


Common Legacy Storage

Sata DOM

Rare Legacy Storage

Retrieved from "https://www.vogonswiki.com/index.php?title=Storage&oldid=4089"