User`s guide

KA52/53/54 Firmware Commands

3.2 Console Commands

3.2.18 UNJAM

The UNJAM command performs an I/O bus reset, by writing a 1 (one) to IPR

55 (decimal). SHAC and SGEC are explicitly reset, EDAL_INTREQ register

error bits are cleared and SCSI_DMA map registers are cleared.

Format:

UNJAM

Example:

>>>UNJAM

>>>

3.2.19 X—Binary Load and Unload

The X command is for use by automatic systems communicating with the

console.

The X command loads or unloads (that is, writes to memory, or reads from

memory) the speciﬁed number of data bytes through the console serial line

(regardless of console type) starting at the speciﬁed address.

Format:

X {address} {count} CR {line_checksum} {data} {data_checksum}

If bit 31 of the count is clear, data is received by the console and deposited into

memory. If bit 31 is set, data is read from memory and sent by the console.

The remaining bits in the count are a positive number indicating the number

of bytes to load or unload.

The console accepts the command upon receiving the carriage return. The next

byte the console receives is the command checksum, which is not echoed. The

command checksum is veriﬁed by adding all command characters, including

the checksum and separating space (but not including the terminating carriage

return, rubouts, or characters deleted by rubout), into an 8-bit register initially

set to zero. If no errors occur, the result is zero. If the command checksum

is correct, the console responds with the input prompt and either sends

data to the requester or prepares to receive data. If the command checksum

is in error, the console responds with an error message. The intent is to

prevent inadvertent operator entry into a mode where the console is accepting

characters from the keyboard as data, with no escape mechanism possible.

If the command is a load (bit 31 of the count is clear), the console responds

with the input prompt (>>>), then accepts the speciﬁed number of bytes of data

for depositing to memory, and an additional byte of received data checksum.

The data is veriﬁed by adding all data characters and the checksum character

3–34 KA52/53/54 Firmware Commands