10. Using the PROM Programmer
53
cycle immediately, the new PROM should be in place
before an affirmative response is given. A “no ”
response restarts the program.
The Section
Operations and Commands
gives
details and examples of each operation.
Error Messages
Whenever the program receives an inappropriate
response to a question, it types a “?” and repeats the
question. It continues this reaction to each incorrect
response until an acceptable one is received. Then, it
will proceed.
The “?” is also generated if a number less than 8 is
entered in response to the PAGE? question or if the
user asks to program a 1702 (a non-existent function).
The following error messages may also be generated
when a tape-read operation is being performed:
NO OBJECT CODE
or
FORMAT ERROR
or
LOAD ABORTED
The last message follows a non-recoverable error
message.
Aborting Operations
When a PROM is being verified, a list of errors is
generated showing any mismatches between the
PROM data and what is in the RAM buffer. A long
typeout can be halted by pressing the BREAK key.
Because the BREAK key is sampled at the end of each
typed line, it must be held down long enough to be
“seen” by the program. The message
***ABORTED***
is typed and, when the BREAK key is released, the
program restarts from the beginning.
A programming operation can be aborted by
pressing and holding the BREAK key. Again, the
message is typed and the program restarts. Response
to this key may take a few seconds.
Correcting Typing Errors
All numbers entered in response to a question must
be followed by a carriage return (CR). The program
looks only at the last two or four digits, as appropriate,
that have been entered before the CR. Any preceding
digits are ignored. This feature provides a convenient
means of correcting typing errors. The user needs only
to continue typing until the correct digits have been
entered before pushing CR. For example, typing
27142716(CR)
is equivalent to
2716(CR)
Or, in response to the PAGE# = question, typing
41008(CR)
is equivalent to
08(CR)
Inappropriate responses result in a “?” appearing and
the question reasked as described in the subsection
“Error Messages”. These kinds of errors are corrected
by simply entering a valid response on the next try.
Errors of the third kind, in which an incorrect
though valid response is made, must be corrected by
pressing the RESET button on the MCDS and
restarting the program with the monitor program’s P
command. For example, if a “V” command is
inadvertently entered instead of the “P ” command, the
program should be restarted to correct the situation.
Precautions
A PROM should never be inserted or removed with
power on. The user should always make sure that the
power ON/ OFF switch S2 on the PROM programmer
module is in the OFF position before inserting or
removing a PROM.
To prevent any potential problems, the external
power supplies (programming power and—9 volts),
when present, should be sequenced on simultaneously
or after the MCDS is turned on and shut offbefore or
at the same time the MCDS is shut off.
There is another switch (S1) on the PROM
Programmer board that selects between a 1702 and
CDP18U42 configuration for socket 1.
NOTE: This switch should never be in the 1702
position if a CDP18U42 is in the socket and the - 9 -
volt supply active.
If such were the case, —9 volts
would be connected to an input pin of the CDP18U42,
and a destructive latch-up condition could be triggered
in the device. If the program generates the warning
message
SET SWITCH!
it detects the wrong position after the program has
started and waits before proceeding. This warning,
however, should not be relied on to prevent damage to
the device.
Before inserting a CDP18U42, be sure
switch S1 is in the correct position.
The user should be sure to insert each PROM into its
correct socket and be sure that it is properly oriented.
Pin 1 is the pin adjacent to the handle of the zero-
insertion force sockets.
Never have more than one
PROM in the module at any time.
Because the PROM
sockets share common address and data buses,
contention or loading problems could be caused if
more than one device is inserted. Additionally,
extraneous signals to a socket which should be empty
might cause harm to a device left in it.
The PROM programmer software derives its timing
from the 2.0-MHz clock frequency of the crystal on the
CDP18S601 Microboard Computer Module. If this
frequency is changed, the results are unpredictable.
Also, note the power requirements for the PROM
Programmer module as given in Appendix I. If
additional modules are installed in the MCDS that
could tax the internal power supplies to their limits,
these modules should be removed before attempting to
run the programmer.
