Texas Instruments 990 Operation Manual page 27

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945255-9701
2.3 HARDWARE OPERATION
The programmer panel controls and indicators are described in detail in the Model 990/4
Computer System Hardware Reference Manual, Manual No.
945251~9701.
The 733 ASR data terminal's controls and indicators and operation of the terminal are described
in detail in the Model 990 Computer Model 733 ASR/KSR Data Terminal Installation and
Operation, Manual No. 945259-9701.
The user should be aware of the following points regarding use of the system software with the
data terminal:
• The Prototyping System Software requires that tapes be written in line tape format
rather than continuous tape format. In line format, the tape buffer is written to tape
when a carriage return is encountered. To place the 733 ASR in line format, set the
TAPE FORMAT switch to the LINE position.
• A tape should always be rewound completely:
• After a cassette tape is installed in a tape transport.
• After every initialization of power.
• Before removing a cassette tape from a tape transport.
• Before switching off the power to the· data terminal.
The PROM Programming Module is a software-controlled module that provides an interface
between the 990/4 . microcomputer and an external chassis containing power supplies and
interchan,geable circuitry on an adaptor to program specific types of PROM devices. This module
operates as a CRU device.
Detailed information about the PROM Programming module can be found in the Model 990
Computer PROM Programming Module Installation and Operation, Manual No 945258-9701.
Software initiates the programming cycle and determines the duty cycle. Software has direct
control over the PROM address and the data to be programmed; it has limited control over the
width of the pulse used to program the PROMs. The data address and pulse width information
are placed into input registers.
Each PROM or family of PROMs has different requirements because of its programming
characteristics. The adaptor, a type of interface card, handles these differences. It provides any
buffering of the address and data. lines and regulates the dc voltages present in the external
chassis that are used for control and programming.
2.4 PROTOTYPING SYSTEM SOFTWARE CASSETTE GENERATION
The Prototyping System Software cassette tape consists of 15 fIles and is a complete object tape
for the Prototyping System. The fIles on this tape are (in order):
1. Text - Description of tape and copying instructions
2. PX9UFL - Up front loader
3. PX9MTP - Monitor (root segment)
2-3
Digital Systems Division .