How the Unit Works
© Diebold Election Systems, Inc. 2002 AccuVote-OS Hardware Guide
9
•
external button interface
The parallel I/O lines are used to control or monitor the ballot reader interface, power monitoring
interface, ballot deflector/feeder controller, internal printer control, and external button interface.
Only one of the two DMA channels is used to transfer the reader data to the CPU board’s RAM.
Both serial I/O channels are used, one for direct serial communication and one for the internal
modem communications.
Note that the ballot reader interface is discussed in
Reader DMA interface
above.
2.1.8. ROM memory
Each AccuVote-OS is operated by the program (firmware) stored on EPROM chips. AccuVote-
OS units use either two ROM chips if they are used for precinct polling or only one ROM chip for
central counting mode. ROM chips are non-volatile memory devices. Note that all information
concerning your jurisdiction, election and ballots is stored on the memory card and not on the
ROM chips.
Firmware is upgraded by replacing ROM sets and are reflected by ROM release numbers such
1.94. For a detailed look at the format of the ROM labeling system, see
Appendix A: ROM
Labels
. The following is a brief description of the label fields.
•
a
release number
of the form
n.nmx
(ie. 1.94) where
n.n
identifies the host software level
that supports this release,
m
is a major variation of the firmware that requires distinct host
level support, and
x
is the incremental release letter,
•
the
release type
as one of General Release (
Rel
), Beta (
Beta
), Alpha (
Alpha
), or Test
(
Test
) where General is a general release, Beta is a controlled release, Alpha is a pre-
release, and Test has test code enabled and is undergoing pre-release testing,
•
the
application
as one of Precinct Counter (
PC
), Central Counter (
CC
), or Diagnostics
Test (
DT
),
•
the
base language
which currently is one of American English (
AE
) or Canadian French
(
CF
),
•
the
EPROM checksum
in a four digit hexadecimal (e.g. B35D) used to verify the
correctness of the code on the ROM,
•
the
ROM socket
location (
A
or
B
) that the chip resides in, and
•
the
date
the release was made in the international format YY-MM-DD.
Prior to release 1.92o, labels lacked the release type, the application, and the base language
sections and therefore each variation required a separate release number.
2.1.9. RAM memory
The volatile memory used while the program is running is provided by two static RAM chips.
RAM capacity can be achieved using two 32Kb, 64Kb, or 128Kb chips or combination of chip
sizes depending on the configuration of your AccuVote-OS unit. The RAM stores temporary
results of program execution and other variables prior to storage in the non-volatile external
memory card.
2.1.10.
32Kb/64Kb/128Kb memory card interface
Memory cards are used to store precinct, ballot and election results information for each voting
center. Memory cards are only required for precinct polling and not for central count AccuVote-
OS units.
