SimonSoft's IDE-hardware for ATARI-computers.

Chapter 2B, IDE-Interface internally.
THIS INTERFACE USES PORT $D100

Parts needed:
-------------
One IDE connector
One 74LS04 (NOT), 2/6 used
One 74LS32 (OR),  2/4 used
Some wires and a handy friend :-)

IDE connector inside ATARI 800XL connection:
--------------------------------------------
Viewed left-right solderside
Top row is 1-3-5 etc.         Connect in ATARI-XL
Bottom row is 2-4-6 etc.      IC Pin Chip

1  pull up (4.7KOhm)     ->   U4 24 Basic-rom
2  ground                ->   U4 12 Basic-rom
3  D7                    ->   U4 17 Basic-rom
4  ground                ->   U4 12 Basic-rom
5  D6                    ->   U4 16 Basic-rom
6  ground                ->   U4 12 Basic-rom
7  D5                    ->   U4 15 Basic-rom
8  ground                ->   U4 12 Basic-rom
9  D4                    ->   U4 14 Basic-rom
10 ground                ->   U4 12 Basic-rom
11 D3                    ->   U4 13 Basic-rom
12 ground                ->   U4 12 Basic-rom
13 D2                    ->   U4 11 Basic-rom
14 ground                ->   U4 12 Basic-rom
15 D1                    ->   U4 10 Basic-rom
16 ground                ->   U4 12 Basic-rom
17 D0                    ->   U4  9 Basic-rom
18 ground                ->   U4 12 Basic-rom
19 ground                ->   U4 12 Basic-rom
20 not connected
21 not connected
22 ground                ->   U4 12 Basic-rom
23 IOwrite               (see chips)
24 ground                ->   U4 12 Basic-rom
25 IOread                (see chips)
26 ground                ->   U4 12 Basic-rom
27 not connected
28 not connected
29 not connected
30 ground                ->   U4 12 Basic-rom
31 not connected
32 not connected
33 A1                    ->   U4  7 Basic-rom
34 not connected
35 A0                    ->   U4  8 Basic-rom
36 A2                    ->   U4  6 Basic-rom
37 IOadress              ->   U2 14 74LS138
38 pull up (4.7KOhm)     ->   U4 24 Basic-rom
39 not connected
40 ground                ->   U4 12 Basic-rom

---------------------------------------------
The IDE Flatcable marked side goes into pin 1
of your IDE-connector. Marking is red / black
---------------------------------------------

Chips:
------
The numbers are the pinnumbers of the corresponding chip.
Each chip has pin 7 connected to ground
Each chip had pin 14 connected to the 5 Volt supply

R/W--------------------1(OR)3----->IOwrite
                         2
                         |
O2--1(NOT)2--------------+
                         |
			 5
R/W-3(NOT)4----------- 4(OR)6----->IOread

R/W    : U8 36 CPU
O2     : U8 39 CPU
5 Volt : U4 24 Basic-rom
Ground : U4 12 Basic-rom

(Version-1b, Edited 25-06-2000 By Mr. Atari. No warranty)