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Atari Technical Bulletin
Number: STE-0001
Date: September 13, 1991
Page 1 of 1


Product(s) Affected:	STE, (MEGA STE)
Model:			All models
Type of ATB:		As Needed
ECO #:			N/A

Reason for ATB:

Audio distortion caused by shifter I.C. not installed correctly.


Notes:

Description			Part Number	Location

Shifter Revision B		C300588-001	U401
Shifter Revision D		C301712-001	U401
74F374 IC				C300259-374	U500, U501


Symptoms of Problem:

Audio distortion during DMA sound.


Tests to Determine if Problem Exists:

Check stereo sound port with oscilloscope using diagnostic cartridge to see if waveform is distorted.  (SEE AUDIO TEST IN FIELD SERVICE MANUAL)


Solution:

Because of timing restraints with the revision B shifter (C300588-001) there is a restriction on venders for IC 74F374 (C300259-374) at locations U500 and U501. Revision D shifters (C301712-001) may use any 74LS374 vender.


Shifter version

C300588-001 Rev B	Use 74F374 vendors	Motorola MC74F374N
							Texas Instruments SN74F374N
C301712-001 Rev D	Use any 74F374 vendor