Software Considerations - RCA CDPl8S693 User Manual

52
User Manual for Microboard Computer Development System CDP18S693 & CDP18S694
(HEXADECIMAL)
BASIC
DATA
BUFFER
(2 K I LOB fTES)
STACK
I
PROM
PROGRAM
SOFTWARE
Fig. 17—Memory map for PROM
Programmer software.
The response must be a one- or two-digit hexadecimal
number equal to or greater than eight. Because a
leading zero is assumed, only a single digit has to be
entered for pages 8 through F. A number less than
eight is not accepted by the program, thereby
preventing accidental overwrite of some areas.
Additional RAM can be used for additional page
buffer areas.
The user can copy a PROM into any page ( ^ 8),
program a PROM from any page, or verify a PROM
against any page. He does not necessarily have to start
at page 8 and can take advantage of additional RAM if
the MCDS is equipped with more than 4 kilobytes.
However, when an object file is loaded into the buffer
area, loading starts at address 0800. Likewise, when
the buffer area is saved on a disk, the SAVEing begins
at address 0800. Refer to the Section Operations and
Commands for details on the operation of the object
file reader and SAVE programs.
It is relatively easy to copy two smaller PROM 's into
one larger one. For example, to copy two 2758's into
one 2716, the following steps would be followed.
(1) Copy the first 2758 starting at page 8. It will
occupy two pages, addresses 0800 through 08FF.
(2) Copy the second 2758 starting at page A. It will
occupy addresses 0G00 through OFFF.
(3) Then, program a 2716 starting at page 8.
Reversing the procedure would permit program­
ming several smaller PROM 's from a larger one. Some
care must be exercised in keeping track of where data is
loaded in buffer memory for these combined
operations. The software will not prevent overwriting
of data in the buffer area because that may be the
desired operation.
When programming takes place, data is taken from
the starting page specified for the appropriate number
ADDRESS
OFFF
0800
07FF
0000
9 2 C S -3 2 0 2 6 R I
of bytes. Thus, the data to be programmed must be
contiguous in the buffer area.

Software Considerations

General Procedure
The PROM Programmer software is designed to
prompt each step of a procedure so that operation of
the system is self-explanatory and, it is hoped,
relatively error-proof. For each type of operation
(except SAVE) the user is asked to identify the type of
PROM being used and whether positive (noninverted)
or negative (inverted) data is to be used. When the
program is started, and after completion of each
operation, the following message is typed, asking what
operation is next.
F, V, P, C, S, J, U?
The single letters refer to the following operations. The
user should enter the appropriate letter.
F—Fill selected pages of the RAM buffer with 1 's
(positive logic) or O's (negative logic)
V—Verify a PROM against the RAM buffer or a
file
P—Program a PROM from the RAM buffer ora
file
C—Copy a PROM into the RAM buffer
S—Save the RAM buffer on a file
J —Rewind the tape
U—Exit to the monitor
For all except the SAVE operation, the PROM
Programmer asks for the PROM type by the message
TYPE#?
The user should enter one of the following:
1702, 1842, 2708, 2758, or 2716
followed by a carriage return (CR).
The next question asked is whether the operation is
to be performed with positive logic (non-inverted data)
or negative logic (inverted data).
LOGIC =P, N?
The user replies by typing a P for positive logic or an N
for negative logic.
These three prompts are common for the V, C, P,
and F commands. All operations also have in common
the manipulation of data in the RAM buffer area
previously described. Data to be programmed goes to
a PROM from the buffer area. Likewise, data copied
from a PROM goes into the buffer, etc. Succeeding
questions ferret out the area of RAM to be used.
When an operation is completed, the program types
DONE
In .the case of a verify (V) or programming (D)
sequence, it asks if the user wants to repeat the
operation with a question such as
REPROGRAM 1842?
The user responds with a "Y" for yes or an "N" for no.
Because a "yes" response starts another programming