[PageStream 2 document DIAG0002.DOC: 8.50 x 11.00 in, 2 objects]

--- Page 1 ---

Atari Technical Bulletin
Number: DIAG-0002
Date: July 30, 1992
Page 1 of  1


Product(s) Affected:	All
Model:				All
Type of ATB:			Information Only
ECO #: 				N/A

Reason for ATB:

Compatibility problem between TOS and diagnostics.


Notes:

There is a compatibility problem between TOS and diagnostics (depending on the rev. level used). This has always been a problem in the past and required careful matching of the TOS and diagnostic levels. To eliminate this problem a new system was incorporated that wrote a 16 bit CRC value into the last two locations  in each  ROM/EPROM.  The diagnostics need only recalculate the CRC and then compare with the values found in the ROM/EPROM. This system was to be implemented in all new releases of TOS.

Symptoms of Problem:

Failure of Operating System ROM Diagnostic in the TT030 when ROM/EPROM is good.

Solution:

The particular situation for the TT030 is as follows:

TOS version 3.01 8/9/90 is the last version using the old system. TT030 diagnostics rev. 1.1 is the only version that will work with this TOS.

TOS version 3.05  12/05/90 is the next release and uses the new system. Use TT030 diagnostic rev's 1.2 or higher.