IMS IMSAI 8080 User Manual page 518

3. Check the CRI Rate Jumpers.
User Guide.
4. Check to insure that Input Data appears at
U25-2. If Data appears, check the operation
of the shift registers at U24 anji U25.
no Data appears, check the zero crossing
detector at U34.
Refer to the CRI Theory of Operation for
further timing problems in this area.
5. Check the setting of U19-7
MIO
Debugging Information
Refer to the
If
(Read Phase Jumper).