DECSYSTEM 2020 RH11-TM02/03-TU45/TU77 BASIC DEVICE DIAGNOSTIC (DSTUA) Space Forward and Space Reverse operations fail to detect Tape Mark

[jfcl]

The Space Forward command moves the tape forward (toward EOT) on the selected transport over the number of records specified by the Frame Count register. Each time a new record is detected, the Frame Counter is incremented.

The Space Forward function terminates when any of the following conditions exist:

1. A Tape Mark (TM) is detected. In that case, assert Tape Mark (MTDS[TM] = 1) and position the file just after the tape mark, or
2. An end-of-file is detected. In that case, assert End-of-Tape (MTDS[EOT] = 1) and position the file at the end-of-file, or
3. The contents of the Frame Counter register is incremented to zero.

When a Tape Mark (TM) or End-of-Tape (EOT) is detected, the contents of the Frame Count Register indicates the number of records that were spaced over.

Frame Check Error (MTER[FCE]) should be asserted when a space operation has terminated and the Frame Counter Register is not cleared. Asserting Frame Check Error (MTER[FCE]) should assert Composite Error (MTDS[ERR]).

Subtest 8 in DSTUA TST114, TST117, TST120, and TST122 fails to detect Tape Mark during Space Forward and Space Reverse operations and continues the Space operation until the Frame Count is zero. FCE is not asserted as expected. The tape is positioned at the wrong place.

Subtest 9 DSTUA TST114, TST117, TST120, and TST122 notes that the Frame Count did not stop incrementing because the Tape Mark was never found. Therefore the expected Frame Count is incorrect.

*** TST # 117 ; TM03/TU77 0/0 ; ERR PC = 36235
*** SIMPLE MOTION AND DATA XFERS - NRZ

INCORRECT FRM CNT AFTER DETECTION OF TAPE MARK
    DURING SPACE - SHOULD RESULT IN EARLY TERMINATION
GOOD: 177777  BAD: 177776
POSSIBLE BOARDS:  M8934/5, M8909/9, M8933/7,

MTER BIT 26-FCE WAS 0; SHOULD BE 1;   MTER  REG= 000000
POSSIBLE BOARDS:  M8909/9, M8915/8, M8934/5,

MTDS BIT 21-ERR WAS 0; SHOULD BE 1;   MTDS  REG= 010624
POSSIBLE BOARDS:  M8909/9,

ERROR WAS DURING SUBTEST 8.

*** TST # 117 ; TM03/TU77 0/0 ; ERR PC = 36315
*** SIMPLE MOTION AND DATA XFERS - NRZ

INCORRECT FRM CNT AFTER DETECTION OF TAPE MARK
    DURING SPACE - SHOULD RESULT IN EARLY TERMINATION
GOOD: 177777  BAD: 177776
POSSIBLE BOARDS:  M8934/5, M8909/9, M8933/7,

MTER BIT 26-FCE WAS 0; SHOULD BE 1;   MTER  REG= 000000
POSSIBLE BOARDS:  M8909/9, M8915/8, M8934/5,

ERROR WAS DURING SUBTEST 9.