Atari 1040STE, Field Service Manual

Page: 33 / 81

28
3.6 TEST MENU
The normal screen will be dark blue with white letters. The test title and revision
number are displayed at the top, with the amount of RAM and keyboard controller
revision below, and a test menu below that. To select tests, the user types the keys
corresponding to those tests and the
[Return] key. Many iterations of the test or
tests chosen can be run by typing in the number of cycles just before typing
RETURN. Typing a zero will cause the test sequence to run continuously. To stop a
cycle before completion, hit the
[Esc] key (there may be some delay in some tests
before the test stops). As each cycle completes, the total number of cycles will be
displayed on the screen.
3.6.1 Main Menu (Typical)
The RAM size, keyboard revision, O.S. version, country (or language), and television
standard (PAL or NTSC) are shown.
The 'Q' selection sequences through all the tests which do not require operator inter-
action. The 'Z' selection sequences through RAM, ROM, Color, Keyboard, and
Timing, Audio and short BLiT tests. Selection 'E' enables the operator to examine or
modify RAM or hardware registers. 'B' enables the operator to change the baud rate
on the RS232 port. Pressing the up arrow increases it, pressing the down arrow
decreases it.
Pressing '?' or the
[Help] key brings up a brief synopsis of the cartridge functions.
After a test (or series of tests) completes. the passlfail status and error report, if any,
will be displayed. Press the space bar to return to the menu.
If multiple tests are selected, the sequence can be halted before completion by
pressing the
[Esc] key. At the completion of the current test, the sequence will halt,
with the options of either continuing or returning to the menu. In some cases there
will be considerable delay before the current test completes and the keystroke is
detected.
3.7 RAM TEST (R)
RAM is tested in three stages: low 2 kbytes, middle (up to 64K), and from 64K to top.
The test patterns used are: all 1's, all 0's, a counting pattern (data = low word of the
address), reverse counting pattern (data = complement of address low word). The
counting pattern is copied from the top and bottom of a 32 kbyte buffer into the
current 32 kbytes of video RAM to a new area, verifies the pattern, and repeats the
test, until the top of RAM is reached. Finally, addressing at 64K boundaries is
checked by writing unique patterns in the last 256 bytes of each 64K block.
If an error occurs, on red screen the error code is displayed, followed by the address,
data written, data read, and the bits which did not agree. In example:
3.7.1 RAM Error Codes
Except where noted, repair by replacing the RAM chip corresponding to the indicated
bit(s).