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Our IDE Technical Support / Technical Assistance Page, devised over the years by Unitech Electronics Pty. Ltd.

Phone: +61 2 9820 - 3555

Updated and current from September 5th 2001
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Another of Unitech Electronics' unique Services !


Last updated May 28th 2002 - There will be no further updates of this page

The information contained herein is to be used as a guide only.

To the mini ide information page


Integrated Drive Electronics or I D E = (Intelligent Drive Electronics)   Hmmmm .... Often a contradiction in terms.

On Amiga's, often files larger than approx 128K are corrupted when copied to or from an IDE hard drive, this
situation exists as a result of the older Amiga's IDE input port ( 8520 CIA ) not keeping up with current
technology advance in speed transfer rates.   There is a mod of fitting a 8520 B Surface Mount Device
chip, which incidentally is faster
This modification ( 8520 B with PLCC socket fitted ) with parts and labour is $ 160.00 + GST = $ 176.00 including GST

It is felt that the next generation of AMIGA's will embrace this technology and will be reflected in the newer third
party peripherals in production now.

With the release of OS 3.5, OS 3.9 and the soon newcomer OS 4.0 this was overcome as well as the 4.3 GB barrier,
the new OS limit is 20 Terra-bytes and yes that is correct, the hard drive size barrier is now 20 terra-bytes !


Set "MaxTransfer" for every partition on the hard drive to 0x0001FE00 or 128K.   Older IDE drives may even require
setting MaxTransfer to 0x0000FFFF, or 64K. ( see our HARD DRIVE Info page ) for hard drive set-ups.

It may be possible that some newer drives may need a setting of 0x0000FE00 to accommodate the drive in your.  
particular AMIGA and the AMIGA A4000's inbuilt controller situation.

This problem is due to the way some IDE hard drives respond to requests for large blocks of data.
Please Note that MaxTransfer is * NOT* "maximum transfer rate" but rather "Maximum Transfer Size."), or lower
power supply input to the 12 volts line can exhibit this kind of symptom, make sure that your power supply can
deliver the required current to the drive for proper running, ie: 12 volts consistently.
Remember, hard drives consume more power at startup that actually when running.

This is called the "in-rush current".

In an Amiga situation, some IDE drives may actually be ready to be at full "Revs" on power-up, slow to spin-up to
their correct operational speed. eg: 5400 rpm or 7200 rpm and some Amiga video production IDE drives are at a
a blistering 10,000 rpm ! These dedicated Amiga A4000's are specifically used for television and video production

These are "delay to spin" type drives and are slow to arrive at their nominal operating revolution minute, is this
a design flaw ?   No, not really, the hard drive manufacturer's engineers designed some drives to do this
slow start-up and you guessed it, for the IBM compatible computers.  So, again, it's a PC thing holding us back.

This "slow or delayed spin-up" can cause the A4000 to fail to boot. The machine may just sit there and "vege-out"
with the drive light on or off, or it may come up with the purple "Insert Floppy Disk" screen, as in a A4000 without
a Hard Drive.

Some IDE drives do this once in a while, you may hear a " clicking sound " as the drive does its self-test then
decides it's not up to booting today.

It may work after a reset, or may require a power-down to revive it.  This problem may occur more often
with a master-slave drive setup.

Another finding was that some brands of hard drives when mounted in an AMIGA could not sustain a constant flow
of data input through their buffers.  This problem has been rectified by current technology, though the
older Amiga controllers cannot avail themselves to the newer speeds, due to the lack of good fresh drivers in Hard
Drive software. Most Hard drive manufacturer's software applications are written specifically for IBM compatibles

This was due, it is believed, to be due to the poor transfer rate through the inadequate buffer speed.  
This will not apply to all newer models however.

In some Amiga A4000's (and on Some A1200's) it is possible that the hard drives would not boot at all, resulting in
the "purple" (b>INSERT FLOPPY DISK screen being present, which is quite annoying to state the very obvious.

A solution to the problem was thoroughly researched by Jeff Rose , managing director of Unitech Electronics P.L.
and this problem is overcome by a simple, yet ingenious " add-in " circuit consisting of two logic chips and a few
modifications to the A4000's Motherboard. This mod was pioneered in Sydney by Unitech Electronics Pty. Ltd. and it
is installed here in St Andrews, Sydney as an "In-House" as a technical modification with a parts and labour service
charge of AUD$ 125.00 + GST = AUD$ 137.50 . Note: Your A4000 must be 100% working before we perform this

We have in the past years received items for modification, that when tested fail to even turn on something the
clients tried to make us "wear", frankly that is not on. We do test every Amiga owners computer to determine life
or no life and if found to be faulty at the pre-inspection stage, you can rest assured, you will be notified forthwith

This mod we have also placed on aminet as   Delayccta4000.lha   for everyone to use.

This mod can also be located here as   Delayccta4000.lha   also for everyone to use.

Disclaimer: The information contained herein on this web site is believed to be accurate.
No responsibilities is taken for typographical errors or omissions or errors of any kind.

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