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No Fragments Archive 10: Diskmags
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nf_archive_10.iso
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IINFO53.MSA
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TEXT_HOSTADAP.TXT
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1991-07-11
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6KB
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131 lines
****************
ICD HOST ADAPTOR
****************
by ACE member Malcom Hardy
I purchased one of the first 1040STe's to reach Australia which
was about 14 months ago. About six months later I heard about the
DMA chip problem and sent my STe in to have the chip replaced. I
had always intended to purchase a hard drive but had been making
do with the one floppy drive. Once I received it back I began
searching for reasonably priced hard drives. It was at this point
that I heard about the ICD host adaptors which enabled oneself to
assemble their own hard drive reasonably cheaply. It sounded simple
enough so I ordered one from the United States. Within two weeks I
had received the Host Adaptor. The Host Adaptor I ordered was the
AdSCSI Plus ST version which includes a battery backed clock and
calendar.
The kit itself includes the Host Adaptor board,software (One
double sided disk),power cable for the drive , Host Adaptor,
DMA cable and a very detailed seventy page instruction book.
You have a choice of connecting a standard PC type hard drive or
to connect a SCSI type drive. The host adaptor can handle two hard
drives. The PC type drive ie; ST506/412 type requires an
additional controller before it can be connected to the Host
Adaptor. This controller is not the same as the usual controller
card in XT's or AT's. A SCSI hard drive has a built in SCSI
controller and can be connected directly to the Host Adaptor.
These are usually more expensive than the other type, but are more
reliable and faster. A SCSI drive nearly ends up costing the same
as an ST506/412 type drive plus controller.
I decided to go with a SCSI type drive and started the painful
process of searching for a reasonably priced one. Most Computer
stores did not understand what I was talking about when I
mentioned SCSI hard drives. After a long search I finally found
someone who knew what I was talking about and was selling hard
drives at reasonable prices. The name of the company is Electronic
Desktop Solutions. They supplied me with a new 45Mbyte NEC SCSI
hard drive for $500.
A few days later I was off to Dick Smiths and Rod Irvings
electronic stores. The following components were purchased;
1. Metal casing to house the drive $35.00
2. Small fan to keep the drive from overheating. $30.00
(12 volt)
3. 50 Conductor cable to connect the drive to the $10.00
Host Adaptor.
4. 50 pin Connectors for the above cable. $ 4.00
( 2 off )
5. Screws, nuts, washers. $10.00
6. Single throw, Single Pole illuminated 240volt $ 5.00
switch.
7. Disk drive power supply. $90.00
After about 16 hours of cutting, soldering, drilling and careful
assembly I had a fully assembled hard drive. It was at this stage
that I started having problems. The power supply that I purchased
was intended for a floppy drive mechanism. A hard drive requires
about half an amp of current. The Host Adaptor board requires
about 0.6 amp. The power supply was rated at a maximum one amp.
When I switched on the power the hard drive would not come up to
speed. At this stage I was starting to think that purchasing a
standard Atari hard drive would have been a lot easier.
Anyway I decided that even though there was a lot of effort
involved it would be well worthwhile in the long run . The drive
would be faster than the standard Atari drive and I would have a
clock/calendar.I found a power supply circuit , purchased the
parts and a 240 volt transformer and assembled the power supply.
I decided to use one power supply to drive the fan and hard drive
and the other power supply to drive the host adaptor. After
reassembling everything I switched it on and everything worked
fine.
The ICD software provided for formatting and initial setup is
excellent and allows to get your system up and running in a
minimum of time. A powerful accessory is provided to
enable/disable and rename partitions.
The following utilities are included with the
formatting and driver software;
ICDTIME.PRG - This program sets the ST's clock and calendar from
the clock in the host adaptor.
IDCHECK.PRG - This program scans the DMA bus and reports other
SCSI devices which are connected.
RATEHD.PRG - This program tests the drive access time and
maximum transfer rate.
This program accurately tests hard drive access,
bypassing any disk cacheing and the hard disk
driver. It allows you to fine tune your hard drive
to get the best performance. Real world access times are
generally higher than manufacturers claimed times.
I obtained the following results with my drive using
an interleave factor of 1:1.
Transfer rate ; 600 Kilobytes/sec
Average access time; 35 millisecs (28 ms claimed )
MAKEPARK.PRG - This program scans for SCSI devices and generates a
program to PARK those selected. (NEC hard drives
are AUTO parking.)
WHEREIS.TOS - This program allows you to search partitions for a
file matching a specified mask.
I have been using my Hard drive for the past three months and am
amazed at the increased speed at which programs and files are loaded and
saved. Also all my files are timestamped with the correct dates
and times now.
It really transforms your ST into a very productive and powerful
tool. One could no doubt build a hard drive cheaper
if they built their own power supply. In the end my drive ended up
costing me around $800. The ICD software and utilities are easy to use
and the clock/calendar is also very useful.
Assembly would be easier if you purchased a pre-machined
case and assembled power supply.
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