Talk:Enhanced Small Disk Interface

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This article is based on material taken from the Free On-line Dictionary of Computing prior to 1 November 2008 and incorporated under the "relicensing" terms of the GFDL, version 1.3 or later.

ESDI and Micro Channel Architecture

Latest comment: 4 years ago4 comments2 people in discussion

The photo in the main article shows an IBM PS/2 hard drive connected to a passive MCA riser card. The hard drive is described as an ESDI type. This is an absurd scenario. The drive has an MCA interface, not ESDI.

Here is a discussion about a 52-pin MCA interface as used in IBM's 2.5" MCA drives:

https://groups.google.com/forum/#!topic/datarecoverycertification/Vz2GIJEagAo

Once again, the drive has been incorrectly identified as ESDI.

106.69.65.79 (talk) 01:35, 13 March 2020 (UTC)Reply

I have wondered about those drive photos as well. I think unless it's positively been verified that MCA drive do use ESDI internally we should leave those photos out of the article. In any case, they're definitely no really good examples for an article on ESDI. --Zac67 (talk) 19:24, 13 March 2020 (UTC)Reply

The following manual confirms that the drive in the deleted photo does in fact have an MCA interface. The hard disk is referred to as an "internal DASD drive".

IBM Personal System/2 Model 55 Technical Reference:

http://www.mcamafia.de/pdf/m55_ssi.pdf

Page 14 lists the "System Board Devices and Features".

The MCA riser card is described as a "Micro Channel Bus Adapter" comprising "4 channel connectors for type 3 adapters":

-- One 16-bit connector with an auxiliary video extension

-- Two 16-bit connectors

-- One 2- by 36-pin card edge connector for the fixed disk drive

This is the relevant IBM spec:

DASD Storage Interface Specification Micro Channel (REV 2.2):

http://web.archive.org/web/19970629055006/http://www.storage.ibm.com/techsup/hddtech/info/j_mcspec.pdf

Here is a brochure and a technical manual for a Maxtor XT-8000E ESDI drive:

http://www.bitsavers.org/pdf/maxtor/brochures/XT-8000E_Brochure_1990.pdf

http://bitsavers.informatik.uni-stuttgart.de/pdf/maxtor/1015226F_XT-8000E_EH_Product_Specification_and_OEM_Technical_Manual_Apr91.pdf

Pages 68 and 76 of the manual have line drawings of the drive and PCB.

Page 80 and onwards has a detailed line drawing of the PCB and its jumper settings.

106.69.65.79 (talk) 21:38, 14 March 2020 (UTC)Reply

… and here is a product manual for a CDC/Seagate Wren II:

http://bitsavers.trailing-edge.com/pdf/cdc/discs/wren/77738035F_Wren_II_Disk_Drive_OEM_Manual_Nov85.pdf

There are block diagrams for ESDI and SCSI interfaces on pages 22 and 23, respectively. The SCSI version appears to be an ESDI drive with a SCSI bridge. Page 14 has a line drawing of the interface connections and jumper settings for the ESDI version.

106.69.65.79 (talk) 00:08, 15 March 2020 (UTC)Reply