Enum AlarmDetails 

pub enum AlarmDetails {
    PSAL(u32, String),
    OCSAL(Instruction, String),
    QSAL(Instruction, BadMemOp, String),
    IOSAL {
        unit: Unsigned6Bit,
        operand: Option<Unsigned18Bit>,
        message: String,
    },
    MISAL {
        affected_unit: Unsigned6Bit,
    },
    ROUNDTUITAL {
        explanation: String,
        bug_report_url: &'static str,
    },
    DEFERLOOPAL {
        address: Unsigned18Bit,
    },
    BUGAL {
        activity: BugActivity,
        diagnostics: CurrentInstructionDiagnostics,
        message: String,
    },
}

AlarmsDetails variant names are from User’s Handbook section 5-2.2; full names are taken from section 10-2.5.1 (vol 2) of the Technical Manual.

These acrronyms are upper case to follow the names in the TX-2 documentation.

Unimplemented Alarms

Alarms we have not implemented:

Mnemonic	Description	Reason why It’s not Included
SYAL1	Sync System Alarm (see User Handbook page 5-21).	Not yet implemented.
SYAL2	Sync System Alarm (see User Handbook page 5-21).	Not yet implemented.
MPAL	M memory Parity Alarm	Parity errors are not emulated.
NPAL	N memory Parity Alarm	Parity errors are not emulated.
FPAL	F memory Parity Alarm	Parity errors are not emulated.
XPAL	X memory Parity Alarm	Parity errors are not emulated.
TSAL	T memory selection alarm	Indicates overcurrent in the T Memory. We have no hardware, so no overcurrent.
USAL	U memory selection alarm	Indicates overcurrent in the T Memory. We have no hardware, so no overcurrent.
Mousetrap	Stops the computer when there is a malfunction in the setting of the S-memory flip-flops (or perhaps other reasons chosen by the system maintainers).	Not required.

L. G. Roberts memo of 1965-01-07 seems to indicate that another alarm, SPAL, was introduced later; see http://www.bitsavers.org/pdf/mit/tx-2/rcsri.org_library_tx2/TX2-Memos-General_196407.pdf.

Variants

PSAL(u32, String)

P Memory Cycle Selection Alarm. This fires when we attempt to fetch an instruction (but not an operand) from an invalid address.

OCSAL(Instruction, String)

Operation Code Alarm. This fires when an instruction word containing an undefined operation code is read out of memory.

Section 10-2.5.3 of the TX-2 Technical Manual (Volume 2) states that this can also happen when an AOP instruction specifies an undefined op code in bits N₂.₆-N₂.₁. An AOP instruction is has opcode number 4, but with bits N₂.₈=0 and N₂.₇=1 (instead of 00 which is the case for an IOS instruction). So far however, we have not found any further information about the interpretation of bits N₂.₆-N₂.₁ for AOP.

QSAL(Instruction, BadMemOp, String)

Q Memory Cycle Selecttion Alarm. Q register (i.e. data fetch address) is set to an invalid address.

IOSAL

In-Out Selection Alarm. I/O Alarm in IOS instruction; device broken/maintenance/nonexistent.

Fields

unit: Unsigned6Bit

The affected unit (as opposed to the sequence number currently executing).

operand: Option<Unsigned18Bit>

message: String

MISAL

In-Out Miss Indication Alarm. Fires when some I/O unit has missed a data item. This generally indicates that the program is too slow for an I/O device. For example because it uses too many hold bits.

Fields

affected_unit: Unsigned6Bit

ROUNDTUITAL

Indicates that something is not implemented in the emulator. This alarm didn’t exist in the real TX-2.

Fields

explanation: String

bug_report_url: &'static str

DEFERLOOPAL

Loop in deferred addressing (detection of this is not a feature of the TX-2, this occurs only in the emulator).

Fields

address: Unsigned18Bit

address is some address within the loop.

BUGAL

There is a bug in the simulator.

Fields

activity: BugActivity

What were we doing?

diagnostics: CurrentInstructionDiagnostics

What instruction was executing?

message: String

What went wrong?

Implementations

impl AlarmDetails

pub fn kind(&self) -> AlarmKind

Trait Implementations

impl Clone for AlarmDetails

fn clone(&self) -> AlarmDetails

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AlarmDetails

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for AlarmDetails

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.