Setup and Benchmarks of Several ESDI Hard Disks and Controller Cards


To setup an ESDI storage system you will configure the drive first, than configure the controller card, and at last you do the cabling.

Disk Drives and General Drive Setup

Fifteen drives are available and will be tested. Since the formatted capacity depends on the controller card used, unformatted capacity is given.

Let's start with the 10MHz drives ...

Table 1
Tested 10MHz ESDI Drives

Manufacturer Model Form Factor Unformatted Capacity
(Megabyte)
Click on Picture
to Magnify

NEC

D3661

3,5"
half height

134.5

NEC

D5655

5,25"
half height

179.8

IBM

0667-85

5,25"
full height

85

Micropolis

1654

5,25"
half height

178.4

Micropolis

1558

5,25"
full height

382.3

Seagate

ST-1111E

3,5"
half height

111

Imprimis

94186-383

5,25"
full height

383

... proceed to the 15MHz drives ...

Table 2
Tested 15MHz ESDI Drives

Manufacturer Model Form Factor Unformatted Capacity
(Megabyte)
Click on Picture
to Magnify

Micropolis

1664

5,25"
half height

389.3

Micropolis

1568

5,25"
full height

765

Seagate

ST-2383E

5,25"
half height

383

Maxtor

XT-8760E

5,25"
full height

768.9

... continue with the 20MHz drives ...

Table 3
Tested 20MHz ESDI Drives

Manufacturer

Model Form Factor Unformatted Capacity
(Megabyte)
Click on Picture
to Magnify

Hewlett Packard

HP 97548E

5,25"
full height

795.9

Hitachi

DK515

5,25"
full height

780

... move on to the 23MHz drive ...

Table 4
Tested 23MHz ESDI Drive

Manufacturer

Model Form Factor Unformatted Capacity
(Megabyte)
Click on Picture
to Magnify

Micropolis

1538

5,25"
full height

1,043

... and end with the 24MHz drive.

Table 5
Tested 24MHz ESDI Drive

Manufacturer

Model Form Factor Unformatted Capacity
(Megabyte)
Click on Picture
to Magnify

Hitachi

DK516-15

5,25"
full height

1,538




ESDI hard drives demand some configuration work, which is done through jumper blocks or dip switches.

Termination
First of all, the drive at the end of the 34pin control cable has to terminate the ESDI bus. Usually this is done by a resistor IC, which is socketed on the drive's printed circuit board (PCB). All other drives at the control cable have the resistor IC removed.

Drive Address
Every drive connected at the 34pin control cable needs a unique drive address. ESDI drives are numbered from 1 to 7. Most controller cards support two drives, very few four drives. Sometimes the controller manual speaks of drive 0 and drive 1, which - in case of ESDI - always means drive 1 and drive 2.
There are 34pin controller cables with a twist between pin 26 and 28. If you use such a cable, the drive before and the drive behind the twist should be configured as drive 2. Now the position of the drive on the 34pin drive control cable determines the drive address. If the drive is connected behind the twist at the end of the cable, it's drive address is 1. If the drive is connected between the twist and the controller, it's drive address is 2.

Drive Hard Sectored or Controller Soft Sectored?
Generally drives should be configured for hard sector mode, with 36 sectors per track (spt) for 10MHz drives and 54spt for 15MHz drives, thus giving the largest storage space and the highest data throughput possible.
Some controller cards do not support 36/54spt with an 1-1 interleave. Some of these cards ignore the drive's hard sector configuration and instead enforce a soft-sectored low-level-format with 35/53spt. Unfortunately, there are controller cards, which demand hard sector mode, but will not function properly or will function with poor performance, if the user chooses a sectors per track value to high. Hard drives from 20MHz data rate upwards are hard sector formatted only.

Miscellaneous Options
The hard disk should be configured for spin up at power on. Write protection should be disabled.

Last not Least: Grounding of the Disk Drives
All drives but one work when the chassis is grounded to the drive support structure.
In the IBM PS/2 Model 80 environment the drive's chassis has to be divided electronically from the support structure. Use plastic mounting rails for that reason. If the drive's hard disk assembly (HDA) has a grounding connection like e.g. the IBM 0667-85 disk drive, use it to ground the HDA against the support structure.

For the specific drive setup consult the resources page and look for the drive reference. Do not change other than the above mentioned drive pcb jumper settings, if they are in the manufacturer's standard position.

After the drives are jumpered right you might want to have a look on the tested ESDI controller cards.



Table of Content
Setup and Benchmarks of Several ESDI Hard Disks and Controller Cards
Project Introduction

Part 1: ESDI Hardware Setup and System Integration
Tested Hard Drives and General Drive Setup
Tested Controller Cards and General Controller Card Setup
Controller Card and Drive Cabling
System Integration and Manufacturer Specific Setup
Resources, Setup Utilities and Software Driver
ESDI Troubleshooting

Part 2: ESDI Benchmark Tests
Test Setup and Results - 10MHz Systems
Results - 15MHz Systems
Results - 20MHz Systems
Results - 23MHz System
Result - 24MHz System and Conclusions

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© 2016 Wolfgang Gehl