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-
- This is a modified version of MetaDOS 2.6
-
- It allows the use of SCSI-CD-ROMs connected to the ACSI port of the
- Atari ST. No audio functions at all are supported - the system may
- crash if they are called by a program!
-
- Attention - most ST SCSI controllers don't support parity control-
- be sure to disable parity control on your CD-ROM!
-
- The patch was done as follows:
-
- The device driver CDARGEN.BOS was copied to the file CD_ACSI.BOS.
- Then it was edited:
-
- At the address $16E (from program start - no base page or file header etc.)
- the BNE.W command is disabled by two NOP ($4E71).
- This means that the test of the INQUIRY name "CD-ROM" is disabled and always
- positive.
-
- Two routines use the CDAR-505 specific non-standard commands "EXTENDED READ" and
- "EXTENDED SEEK". These commands are 10 bytes long and have to be transformed to
- the "READ" and "SEEK" standard commands that are 6 bytes long.
-
- You'll find the places in CDARGEN.BOS searching for the bytes $00 $40 $00 $18
- (E-Read) or $00 $40 $00 $1B (E-Seek). What is to do? Nothing for the first address
- found for E-Seek - it seems to be never used by the ACSI device.
- At address $12BC and following (E-Read) there the addresses relative to register A1
- have to be changed: The block number has to be written to 1st..3rd command byte
- instead of 3rd..5th, and the number of blocks has to be in the 4th instead of the 8th.
- The ACSI should be done with a 5 instead of a 9 in register D2.
- The same procedure should be done for address $13B4 and following (E-Seek).
-
- I am not responsible for any damage or data loss that is caused by the use of this
- patched driver. You (the user) should check out very careful if your system works
- stable with the patched Metados 2.6
-
- Enjoy it and use your radio for music,
-
- C. Peppermueller
- (E-mail: Christian.Peppermueller@rzmail.uni-erlangen.de)
-
- By the way: This patch seems to work on my old 520ST+ Atari, together with an
- ICD SCSI controller and the SONY CDU55S CD-ROM, even if there is also a
- SEAGATE ST296N hard disc connected, too.
- Do you know how to set the real time clock on the ICD controller (SCSI device 6)?
- If you do, please let me know!
-