www.joogn.de /atari_ide.html Montag, 3. September 2007

IDE Drive in an Atari ST

Attention:
This is a heavily simplified variant of Pera Putnik's Interface. It's more a quick and dirty approach than anything, but it does work. You will definately be required to have schematics of your ST and make some research on your own how to get this circuit into your machine.

Please take also into consideration that my 1040 STfm has not only a TOS 2.06 (as only TOS >= 2.06 checks for IDE drives!) patch built in, but also an 8/16 MHz switch when the 68000 processes internal intructions!

  • Instead of a GAL I use a 74LS133, 74HC32 + Inverters

  • I skipped unnecessary pins: (27)IORDY, (29)DMACK

  • My 2,5'' drive fits into the ST so no 74HCT245 buffers

  • As RES/-FDINT are ''open collector'' in my ST
    I simply connected the ST-Reset with the IDE-Reset
    & -FDINT (Pin 10 on ASCI Harddisk connector) with INTRQ.

    Make sure that the TTL-Type you chose are CMOS compatible. I used a 74F32 in the beginning that caused faulty signal levels and damaged the rootsector of my drive everytime I switched on the ST.

    In case you wonder why my -DTACK goes through TTL-Gates, its because of my aforementioned TOS2.06 & 16MHz Patch in my ST. An ''open collector'' solution will work for you.

    My thanks fly to Pera Putnik and Albin Lass.

    Photos:

  • Schematics
  • Atari 1040STfm 16MHz/4MB/TOS2.06/IDE 250MB
  • Atari TOS 2.06
  • Atari IDE on empty BLITTER socket
  • Atari 4MB RAM / (partly)16MHz
  • IDE-Pinout
      . .  
      . .  
           
    Reset 1 2 GND
    D7 3 4 D8
    D6 5 6 D9
    D5 7 8 D10
    D4 9 10 D11
    D3 11 12 D12
    D2 13 14 D13
    D1 15 16 D14
    D0 17 18 D15
    GND 19 20 KEY
      21 22 GND
    -IOWR 23 24 GND
    -IORD 25 26 GND
      27 28 GND
      29 30 GND
    INTRQ 31 32  
    (A3) A1 33 34  
    (A2) A0 35 36 A2 (A4)
    -CS1FX 37 38 -CS3FX
    DASP 39 40 GND
    +5V 41 42 +5V
    GND 43 44  
    
    From Hardware Register Listing 7.0:
    -------+-----+-----------------------------------------+---
     IDE Controller (Falcon, ST-Book, IDE cards)
    -------+-----+-----------------------------------------+---
    $F00000|long |Data Register                            |R/W
    $F00005|byte |Error Register       BIT 7 6 5 4 3 2 1 0 |R
           |     |Bad block mark ----------' | | | | | | | |
           |     |Uncorrectable error -------' | | | | | | |
           |     |Media change ----------------' | | | | | |
           |     |ID-Field not found ------------' | | | | |
           |     |Media change requested ----------' | | | |
           |     |Command aborted -------------------' | | |
           |     |Track 0 not found -------------------' | |
           |     |DAM not found -------------------------' |
    $F00009|byte |Sector Count Register                    |W
    $F0000D|byte |Sector Number Register                   |W
    $F00011|byte |Cylinder Low Register                    |W
    $F00015|byte |Cylinder High Register                   |W
    $F00019|byte |Drive Head Register                      |W
    $F0001D|byte |Status Register                          |R
    $F0001D|byte |Command Register                         |W
    $F00039|byte |Alternate Status Register                |R
    $F00039|byte |Data Output Register                     |W
    -------+-----+-----------------------------------------+---