Dma Tests; Fioppy Disk Tests - Atari 520STE Field Service Manual

3.15 DMA TESTS (D)
Four sectors (2048 bytes) of data are written to the RAM on the port test fixture via
high speed DMA, then read back and verified. This test is repeated many times for
RAM addresses throughout the range of RAM.
3.15.1 DMA Test Error Codes
D0 DMA Timed Out. No DMA occurred due to faulty DMA Controller, GSTMCU,
or Memory Controller, or the HDINT interrupt was not processed by the MFP.
The failure can be isolated by seeing if the DMA Controller responds to HDRQ
from the test fixture with ACK. Verify the MFP by seeing that the HDINT input
causes an INTR output from the MFP.
D1 DMA Counter Error. The number of bytes transferred was incorrect. The
Memory Controller or DMA Controller is bad.
D2 Data Mismatch Error. The data received from the DMA port was not the same
as the data sent. Replace the DMA Controller If the problem persists, check
the data lines to the port for opens and shorts. A third possibility is that a
defective 1772 is loading the bus.
D3 DMA Controller Not Responding
3.16 FLOPPY DISK TESTS (F)
In a single test mode, a menu is displayed showing seven options:
1. Quick Test. For each disk installed, formats, writes, and reads tracks 0, 1,
and 79 of side 0. If double sided, formats and writes track 79 of side 1 and
verifies that side 0 was not overwritten. If no disks are installed, checks to see
what drives are online and if they are double or single sided. To assure that
the drives are correctly tested, the operator should install menu option 6
before calling the test. Once the test is run, the drives become installed, and
will be displayed on the menu screen.
2. Read Track. Continuously reads a track, for checking alignment with an
analog alignment diskette. The choice of track to be read may be input by the
operator. If [Return] is pressed without entering a number,
3. Interchangeability Test. Checks to see if diskettes from two disk drives each
can be read by the other disk drive.
4. Disk Exerciser. A more thorough disk test; tests all sectors used on the disk
for an indefinite period of time.
5. Copy Protect Tracks. Tests tracks 80–82, which are used by some software
companies for copy protection. Not all manufacturers disk drives will write to
these tracks.
Note: This test is for information only and should not be used to reject a
mechanism.
6. Test Speed. The rotational speed of the drive is tested and displayed on the
screen as the period of rotation. The acceptable range is 196–203
.
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