V1.2
Version history:
V1.2 Fixed bug that caused for example Seagate drives not to work.
V1.1 November 1997: automatic drive identification, new interface with pcb
...NOTE: If IDE-connector pin 28 is not *ALE, you can use resistor pullup
...V1.00002 September 1997 : edited schematic; *ALE should be low.
V1.00001 February 1997  : some editing done
V1.0 1996
DISCLAIMER: I disclaim everything. You use this at your own risk.

These are instructions for building a simple non-autobooting 
IDE-harddisk interface for A500. This is only a hack, and even
if it seems to work it may work unreliably. I have tested the interface
on KS1.3 and KS2.05(ROM 37.300) systems. Drives tested include
the Conner Peripherals CP3044, Western Digital Tidbit 60 (2.5") and
Seagate ST3850 (811 MByte drive). Speeds were about 400 KBytes/second.
Prairietek 120 20MB 2.5" did not work(gave errors.) There is
also a device driver ide.device and its sources included. ide.device 
supports only one drive. It won't work with drives over 4 GBytes.

Building:
There are two versions of the schematics. They decode the interface
to address $DA0000. This can be changed of course, and then it is
necessary to change the software to correspond to the hardware.

1.
schem.iff is the older one. Parts are: 74x688, 74x00, one 74x04 gate
x means 'any' logic family. For example you can use 74F00, 74HCT688 etc.
The cable must be short to minimize transfer errors. (ringing, crosstalk etc.)
Connect any unused chip inputs to Vcc(+5v) or GND. 
2.
plidesch.ps (Postscript file). This version uses a programmable logic
chip, for example a PAL16L8. The equations are in plide.pld (Sprint
format). The interface can be buffered with 74LS245's. Printed circuit
board layouts are: plidetop.ps, plidebot.ps, plideovr.ps(overlay)
The postscripts are packed into plideps.lzh. Use IC-socket in place
of 74LS05, because the interface might work better without that IC.
I have only built a prototype of this and haven't made the PCB.
NOTE:You can try to use the 'interrupt.ide.device' version, if
you install the 74LS05 into it's socket. See devs/README.DEVS. If it
works it has the advantage of saving processor time unlike a busy loop.

The Amiga 500 and ATID connectors can be found from iff-file
Connector.pic (c) P. Pihkala
and the ATID(=ATA/IDE) connector from text file atacon.txt.
To test the interface and find out drive parameters use
the program IdentifyDrive (it's in the software directory)

MOUNTING is needed as the drive doesn't autoconfigurate:
A sample mountlist is in ide.ml. Edit it to give partitions.
The ide.device needs to be in the devs: directory. Select
one of the x.ide.devices from devs directory (README.DEVS)
If you want FastFileSystem:
If the Kickstart is 1.3, there must be L:FastFileSystem.
With KS2.0 don't use the FileSystem = L:fastfilesystem line
in the mountlist.
An example command for introducing a partition to the system:
Mount fre: from ide.ml
useful file for a boot floppy:
startup.seq (rename to s/startup-sequence of the boot floppy)

A KNOWN BUG IS THAT FORMAT ALWAYS SAYS FORMAT FAILED, but the
disk is useful if the format in reality was a success.

See software/READ.ME for descriptions about the files in that
directory.

Author of the rdwt.asm and most of the other files: Mika Leinonen
E-Mail address : l150540@proffa.cc.tut.fi
Web-page(standard drafts here):www.students.tut.fi/%7El150540/ide.html