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Trans lation Fo rmats ProM aster 25 00 User Manua l D-2 1 RCA Cosmac For mat, C ode 70 Data in this form at begin with a sta rt record consisting of the start character (!M or ?M), an address f ield, and a s pace. See Fi…

Translation Formats

D-20 ProMaster 2500 User Manual

Although each data byte has an address, most are implied. Data bytes are

addressed sequentially unless an explicit address is included in the data

stream. This address is preceded by a $ and an A, must contain 2 to 8 hex

or 3 to 11 octal characters, and must be followed by a comma, except for

the ASCII-Hex (Comma) format, which uses a period. The programmer

skips to the new address to store the next data byte; succeeding bytes are

again stored sequentially.

Each format has an end code, which terminates input operations.

However, if a new start code follows within 16 characters of an end code,

input will continue uninterrupted. If no characters come within 2

seconds, input operation is terminated.

After receiving the final end code following an input operation, the

programmer calculates a sumcheck of all incoming data. Optionally, a

sumcheck can also be entered in the input data stream. The programmer

compares this sumcheck with its own calculated sumcheck. If they

match, the programmer will display the sumcheck; if not, a sumcheck

error will be displayed.

Note: The sumcheck field consists of either 2-4 hex or 3-6 octal characters,

sandwiched between the $ and comma characters. The sumcheck

immediately follows an end code. The sumcheck is optional in the input

mode but is always included in the output mode. The most significant

digit of the sumcheck may be 0 or 1 when expressing 16 bits as 6 octal

characters.

The programmer divides the output data into 8-line blocks. Data

transmission is begun with the start code, a nonprintable STX character,

or optionally, SOH.* Data blocks follow, each one prefaced by an address

for the first data byte in the block. The end of transmission is signaled by

the end code, a nonprintable ETX character. Directly following the end

code is a sumcheck of the transferred data.

* ASCII-Octal SMS and ASCII-Hex SMS use SOM (CTRL-R) as a start code and EOM

(CTRL-T) as an end code.

Translation Formats

ProMaster 2500 User Manual D-21

RCA Cosmac Format, Code 70

Data in this format begin with a start record consisting of the start

character (!M or ?M), an address field, and a space. See Figure D-7.

The start character ?M is sent to the programmer by a development

system, followed by the starting address and a data stream which

conforms to the data input format described in the ASCII-Hex and Octal

figure. Transmission stops when the specified number of bytes has been

transmitted.

Address specification is required for only the first data byte in the

transfer. An address must have 1 to 4 hex characters and must be

followed by a space. The programmer records the next hexadecimal

character after the space as the start of the first data byte. (A carriage

return must follow the space if the start code ?M is used.) Succeeding

bytes are recorded sequentially.

Each data record is followed by a comma if the next record is not

preceded by an address, or by a semicolon if it starts with an address.

Records consist of data bytes expressed as 2 hexadecimal characters and

followed by either a comma or semicolon, and a carriage return. The

programmer ignores any characters received between a comma or

semicolon and a carriage return.

The carriage return character is significant to this format because it can

signal either the continuation or the end of data flow; if the carriage

return is preceded by a comma or semicolon, more data must follow; the

absence of a comma or semicolon before the carriage return indicates the

end of transmission.

Output data records are followed by either a comma or a semicolon and a

carriage return. The start-of-file records are expressed exactly as for

input.

Figure D-7

An Example of RCA Cosmac

Format

!M0000 ,

FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF,

FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

Start Record

!M or ?M = Start Characters

0000 = Address

End-of-File Record

Data Records

FF =

, =

; =

2 Hex Characters = (1 Byte)

Bytes per record is variable

End of Record Character

if followed by expressed

address

LEGEND

Nonprinting line feed, carriage return, and nulls

Nonprinting carriage return

0079-2

Translation Formats

D-22 ProMaster 2500 User Manual

Fairchild Fairbug, Code 80

In the Fairbug format, input and output requirements are identical; both

have 8-byte records and identical control characters. Figure D-8 shows a

Fairbug data file. A file begins with a 5-character prefix and ends with a

1-character suffix. The start-of-file character is an S, followed by the

address of the first data byte. Each data byte is represented by 2

hexadecimal characters. The programmer will ignore all characters

received prior to the first S.

Note: Address specification is optional in this format; a record with no address

directly follows the previous record.

Each data record begins with an X and always contains 8 data bytes. A

1-digit hexadecimal checksum follows the data in each data record. The

checksum represents, in hexadecimal notation, the sum of the binary

equivalents of the 16 digits in the record; the half carry from the fourth bit

is ignored.

The programmer ignores any character (except for address characters and

the asterisk character, which terminates the data transfer) between a

checksum and the start character of the next data record. This space can

be used for comments.

The last record consists of an asterisk only, which indicates the end

of file.

Figure D-8

An Example of Fairchild Fairbug

S0000

XFFFFFFFFFFFFFFFFC

Start Record

S = Start Character

0000 = Address Field

End-of-File Record

Data Records

X =

FF =

C =

Data Record Start Character

2 Hex Characters (1 Byte)

Checksum. 1-digit summation

of data in record

0080-2