OKI MSM518222A-XXJS

E2L0067-18-Z2
¡ Semiconductor
MSM518222A
¡ Semiconductor
This version:
Dec. 1998
MSM518222A
262,214-Word ¥ 8-Bit Field Memory
DESCRIPTION
The OKI MSM518222A is a high performance 2-Mbit, 256K ¥ 8-bit, Field Memory. It is designed
for high-speed serial access applications such as HDTVs, conventional NTSC TVs, VTRs, digital
movies and Multi-media systems. It is a FRAM for wide or low end use as general commodity
TVs and VTRs, exclusively. The MSM518222A is not designed for the other use or high end use
in medical systems, professional graphics systems which require long term picture, and data
storage systems and others. The 2-Mbit capacity fits one field of a conventional NTSC TV screen.
Two cascaded MSM518222As make one frame of the screen: two or more MSM518222As can be
cascaded directly without any delay devices between them. (Cascading provides larger storage
depth or a longer delay).
Each of the 8-bit planes has separate serial write and read ports. These employ independent control
clocks to support asynchronous read and write operations. Different clock rates are also supported,
which allow alternate data rates between write and read data streams.
The MSM518222Aprovides high speed FIFO, First-In First-Out, operation without external refreshing:
it refreshes its DRAM storage cells automatically, so that it appears fully static to the users.
Moreover, fully static type memory cells and decoders for serial access enable the refresh free serial
access operation, so that serial read and/or write control clock can be halted high or low for any
duration as long as the power is on. Internal conflicts of memory access and refreshing operations
are prevented by special arbitration logic.
The MSM518222A's function is simple, and similar to a digital delay device whose delay-bit-length
is easily set by reset timing. The delay length, and the number of read delay clocks between write
and read, is determined by externally controlled write and read reset timings.
Additional SRAM serial registers, or line buffers for the initial access of 256 ¥ 8-bit enable high speed
first-bit-access with no clock delay just after the write or read reset timings.
The MSM518222A is similar in operation and functionality to OKI 1-Mbit Field Memory
MSM514221B, with the addition of cascade capability. (As for MSM514221B operation compatible
2-Mbit Field Memory, OKI has the MSM518221A which is a sister device of MSM518222A).
Additionally, the MSM518222A has a write mask function or input enable function (IE), and readdata skipping function or output enable function (OE). The differences between write enable (WE)
and input enable (IE), and between read enable (RE) and output enable (OE) are that WE and RE can
stop serial write/read address increments, but IE and OE cannot stop the increment, when write/
read clocking is continuously applied to MSM518222A. The input enable (IE) function allows the
user to write into selected locations of the memory only, leaving the rest of the memory contents
unchanged. This facilitates data processing to display a "picture in picture" on a TV screen.
1/16
¡ Semiconductor
MSM518222A
FEATURES
• Single power supply : 5 V ±10%
• 512 Rows ¥ 512 Columns ¥ 8 bits
• Fast FIFO (First-In First-Out) operation
• High speed asynchronous serial access
Read/write cycle time
25 ns/30 ns/40 ns
Access time
25 ns/25 ns/30 ns
• Direct cascading capability
• Write mask function (Input enable control)
• Data skipping function (Output enable control)
• Self refresh (No refresh control is required)
• Package options :
28-pin 400 mil plastic ZIP
(ZIP28-P-400-1.27)
28-pin 400 mil plastic SOJ
(SOJ28-P-400-1.27)
28-pin 430 mil plastic SOP
(SOP28-P-430-1.27-K)
(Product : MSM518222A-xxZS)
(Product : MSM518222A-xxJS)
(Product : MSM518222A-xxGS-K)
xx indicates speed rank.
PRODUCT FAMILY
Family
Access Time (Max.)
Cycle Time (Min.)
MSM518222A-25ZS
25 ns
25 ns
MSM518222A-30ZS
25 ns
30 ns
MSM518222A-40ZS
30 ns
40 ns
MSM518222A-25JS
25 ns
25 ns
MSM518222A-30JS
25 ns
30 ns
MSM518222A-40JS
30 ns
40 ns
MSM518222A-30GS-K
25 ns
30 ns
MSM518222A-40GS-K
30 ns
40 ns
Package
400 mil 28-pin ZIP
400 mil 28-pin SOJ
430 mil 28-pin SOP
2/16
¡ Semiconductor
MSM518222A
PIN CONFIGURATION (TOP VIEW)
WE
1
DIN0
3
DIN2
5
VCC
7
DIN5
9
DIN7 11
SWCK 13
NC 15
OE 17
DOUT6 19
DOUT4 21
DOUT3 23
DOUT1 25
RSTR 27
2
IE
4
DIN1
6
DIN3
8
DIN4
10 DIN6
12 RSTW
14 NC
16 RE
18 DOUT7
20 DOUT5
22 VSS
DIN4 1
28 VCC
DIN4 1
28 VCC
DIN5 2
27 DIN3
DIN5 2
27 DIN3
DIN6 3
26 DIN2
DIN6 3
26 DIN2
DIN7 4
25 DIN1
DIN7 4
25 DIN1
RSTW 5
24 DIN0
RSTW 5
24 DIN0
SWCK 6
23 IE
SWCK 6
23 IE
NC 7
22 WE
NC 7
RE 8
21 NC
RE 8
21 NC
OE 9
20 SRCK
OE 9
20 SRCK
DOUT7 10
19 RSTR
DOUT7 10
19 RSTR
DOUT6 11
18 DOUT0
DOUT6 11
18 DOUT0
DOUT5 12
17 DOUT1
DOUT5 12
17 DOUT1
DOUT4 13
16 DOUT2
DOUT4 13
16 DOUT2
VSS 14
15 DOUT3
VSS 14
15 DOUT3
22 WE
24 DOUT2
28-Pin Plastic SOJ
26 DOUT0
28-Pin Plastic SOP
28 SRCK
28-Pin Plastic ZIP
Pin Name
SWCK
SRCK
WE
RE
IE
OE
RSTW
RSTR
DIN0 - 7
DOUT0 - 7
VCC
VSS
NC
Function
Serial Write Clock
Serial Read Clock
Write Enable
Read Enable
Input Enable
Output Enable
Write Reset Clock
Read Reset Clock
Data Input
Data Output
Power Supply (5 V)
Ground (0 V)
No Connection
3/16
RE
Serial
Read
RSTR
SRCK
Controller
512-Word Serial Read Register (¥ 8)
Read Line Buffer
Low-Half (¥ 8)
¡ Semiconductor
Data-out
Buffer (¥ 8)
OE
BLOCK DIAGRAM
DOUT (¥ 8)
Read Line Buffer
High-Half (¥ 8)
256 (¥ 8)
256 (¥ 8)
71-Word
Sub-Register (¥ 8)
X
Decoder
256K (¥ 8)
Memory
Array
Read/Write
and Refresh
Controller
71-Word
Sub-Register (¥ 8)
256 (¥ 8)
Write Line Buffer
Low-Half (¥ 8)
256 (¥ 8)
Clock
Oscillator
Write Line Buffer
High-Half (¥ 8)
512-Word Serial Write Register (¥ 8)
4/16
Data-in
Buffer (¥ 8)
Serial
Write
DIN (¥ 8)
IE
WE
Controller
RSTW
SWCK
MSM518222A
VBB
Generator
¡ Semiconductor
MSM518222A
OPERATION
Write Operation
The write operation is controlled by three clocks, SWCK, RSTW, and WE. Write operation is
accomplished by cycling SWCK, and holding WE high after the write address pointer reset operation
or RSTW.
Each write operation, which begins after RSTW, must contain at least 80 active write cycles, i.e.
SWCK cycles while WE is high. To transfer the last data to the DRAM array, which at that time
is stored in the serial data registers attached to the DRAM array, an RSTW operation is required
after the last SWCK cycle.
Note that every write timing of MSM518222A is delayed by one clock compared with read timings
for easy cascading without any interface delay devices.
Write Reset : RSTW
The first positive transition of SWCK after RSTW becomes high resets the write address counters to
zero. RSTW setup and hold times are referenced to the rising edge of SWCK. Because the write reset
function is solely controlled by the SWCK rising edge after the high level of RSTW, the states of WE
and IE are ignored in the write reset cycle.
Before RSTW may be brought high again for a further reset operation, it must be low for at least two
SWCK cycles.
Data Inputs : DIN0 - 7
Write Clock : SWCK
The SWCK latches the input data on chip when WE is high, and also increments the internal write
address pointer. Data-in setup time tDS, and hold time tDH are referenced to the rising edge of SWCK.
Write Enable : WE
WE is used for data write enable/disable control. WE high level enables the input, and WE low level
disables the input and holds the internal write address pointer. There are no WE disable time (low)
and WE enable time (high) restrictions, because the MSM518222A is in fully static operation as long
as the power is on. Note that WE setup and hold times are referenced to the rising edge of SWCK.
Input Enable : IE
IE is used to enable/disable writing into memory. IE high level enables writing. The internal write
address pointer is always incremented by cycling SWCK regardless of the IE level. Note that IE setup
and hold times are referenced to the rising edge of SWCK.
5/16
¡ Semiconductor
MSM518222A
Read Operation
The read operation is controlled by three clocks, SRCK, RSTR, and RE. Read operation is
accomplished by cycling SRCK, and holding RE high after the read address pointer reset operation
or RSTR.
Each read operation, which begins after RSTR, must contain at least 80 active read cycles, i.e. SRCK
cycles while RE is high.
Read Reset : RSTR
The first positive transition of SRCK after RSTR becomes high resets the read address counters to
zero. RSTR setup and hold times are referenced to the rising edge of SRCK. Because the read reset
function is solely controlled by the SRCK rising edge after the high level of RSTR, the states of RE and
OE are ignored in the read reset cycle.
Before RSTR may be brought high again for a further reset operation, it must be low for at least *two
SRCK cycles.
Data Out : DOUT0 - 7
Read Clock : SRCK
Data is shifted out of the data registers. It is triggered by the rising edge of SRCK when RE is high
during a read operation. The SRCK input increments the internal read address pointer when RE is
high.
The three-state output buffer provides direct TTL compatibility (no pullup resistor required). Data
out is the same polarity as data in. The output becomes valid after the access time interval tAC that
begins with the rising edge of SRCK. *There are no output valid time restrictions on MSM518222A.
Read Enable : RE
The function of RE is to gate the SRCK clock for incrementing the read pointer. When RE is high
before the rising edge of SRCK, the read pointer is incremented. When RE is low, the read pointer
is not incremented. RE setup times (tRENS and tRDSS) and RE hold times (tRENH and tRDSH) are
referenced to the rising edge of the SRCK clock.
Output Enable : OE
OE is used to enable/disable the outputs. OE high level enables the outputs. The internal read
address pointer is always incremented by cycling SRCK regardless of the OE level. Note that OE
setup and hold times are referenced to the rising edge of SRCK.
6/16
¡ Semiconductor
MSM518222A
Power-up and Initialization
On power-up, the device is designed to begin proper operation after at least 100 ms after VCC has
stabilized to a value within the range of recommended operating conditions. After this 100 ms
stabilization interval, the following initialization sequence must be performed.
Because the read and write address counters are not valid after power-up, a minimum of 80 dummy
write operations (SWCK cycles) and read operations (SRCK cycles) must be performed, followed by
an RSTW operation and an RSTR operation, to properly initialize the write and the read address
pointer. Dummy write cycles/RSTW and dummy read cycles/RSTR may occur simultaneously.
If these dummy read and write operations start while VCC and/or the substrate voltage has not
stabilized, it is necessary to perform an RSTR operation plus a minimum of 80 SRCK cycles plus
another RSTR operation, and an RSTW operation plus a minimum of 80 SRCK cycles plus another
RSTW operation to properly initialize read and write address pointers.
Old/New Data Access
There must be a minimum delay of 600 SWCK cycles between writing into memory and reading out
from memory. If reading from the first field starts with an RSTR operation, before the start of writing
the second field (before the next RSTW operation), then the data just written will be read out.
The start of reading out the first field of data may be delayed past the beginning of writing in the
second field of data for as many as 70 SWCK cycles. If the RSTR operation for the first field read-out
occurs less than 70 SWCK cycles after the RSTW operation for the second field write-in, then the
internal buffering of the device assures that the first field will still be read out. The first field of data
that is read out while the second field of data is written is called "old data".
In order to read out "new data", i.e., the second field written in, the delay between an RSTW
operation and an RSTR operation must be at least 600 SRCK cycles. If the delay between RSTW and
RSTR operations is more than 71 but less than 600 cycles, then the data read out will be undetermined.
It may be "old data" or "new" data, or a combination of old and new data. Such a timing should be
avoided.
Cascade Operation
The MSM518222A is designed to allow easy cascading of multiple memory devices. This provides
higher storage depth, or a longer delay than can be achieved with only one memory device.
7/16
¡ Semiconductor
MSM518222A
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings
Symbol
Condition
Rating
Unit
Input Output Voltage
Parameter
VT
at Ta = 25°C, VSS
–1.0 to 7.0
V
Output Current
IOS
Ta = 25°C
50
mA
Power Dissipation
PD
Ta = 25°C
1
W
Operating Temperature
Topr
—
0 to 70
°C
Storage Temperature
Tstg
—
–55 to 150
°C
Recommended Operating Conditions
Parameter
Symbol
Min.
Typ.
Max.
Unit
Power Supply Voltage
VCC
4.5
5.0
5.5
V
Power Supply Voltage
VSS
0
0
0
V
Input High Voltage
VIH
2.4
VCC
VCC + 1
V
Input Low Voltage
VIL
–1.0
0
0.8
V
DC Characteristics
Parameter
Symbol
Condition
Min.
Max.
Unit
Input Leakage Current
ILI
0 < VI < VCC + 1, Other Pins Tested at V = 0 V
–10
10
mA
Output Leakage Current
ILO
0 < VO < VCC
–10
10
mA
Output "H" Level Voltage
VOH
IOH = –1 mA
2.4
—
V
Output "L" Level Voltage
VOL
IOL = 2 mA
—
0.4
V
-25
—
60
Operating Current
ICC1
Minimum Cycle Time, Output Open -30
—
50
-40
—
40
Standby Current
ICC2
Input Pin = VIH / VIL
—
5
Capacitance
mA
mA
(Ta = 25°C, f = 1 MHz)
Parameter
Symbol
Max.
Unit
Input Capacitance (DIN, SWCK, SRCK, RSTW, RSTR, WE, RE, IE, OE)
CI
7
pF
Output Capacitance (DOUT)
CO
7
pF
8/16
¡ Semiconductor
MSM518222A
AC Characteristics
(VCC = 5 V ±10%, Ta = 0°C to 70°C)
MSM518222A-25 MSM518222A-30 MSM518222A-40
Parameter
Symbol
Unit
Min.
Max.
Min.
Max.
Min.
Max.
tAC
—
25
—
25
—
30
ns
DOUT Hold Time from SRCK
tDDCK
6
—
6
—
6
—
ns
DOUT Enable Time from SRCK
tDECK
6
25
6
25
6
25
ns
SWCK "H" Pulse Width
tWSWH
9
—
12
—
17
—
ns
SWCK "L" Pulse Width
tWSWL
9
—
12
—
17
—
ns
Input Data Setup Time
tDS
5
—
5
—
5
—
ns
Input Data Hold Time
tDH
6
—
6
—
6
—
ns
WE Enable Setup Time
tWENS
0
—
0
—
0
—
ns
WE Enable Hold Time
tWENH
5
—
5
—
5
—
ns
WE Disable Setup Time
tWDSS
0
—
0
—
0
—
ns
WE Disable Hold Time
tWDSH
5
—
5
—
5
—
ns
IE Enable Setup Time
tIENS
0
—
0
—
0
—
ns
IE Enable Hold Time
tIENH
5
—
5
—
5
—
ns
IE Disable Setup Time
tIDSS
0
—
0
—
0
—
ns
IE Disable Hold Time
tIDSH
5
—
5
—
5
—
ns
WE "H" Pulse Width
WE "L" Pulse Width
tWWEH
tWWEL
5
5
—
—
10
—
10
—
ns
10
—
10
—
ns
IE "H" Pulse Width
tWIEH
5
—
10
—
10
—
ns
IE "L" Pulse Width
tWIEL
5
—
10
—
10
—
ns
RSTW Setup Time
tRSTWS
0
—
0
—
0
—
ns
RSTW Hold Time
tRSTWH
10
—
10
—
10
—
ns
SRCK "H" Pulse Width
tWSRH
9
—
12
—
17
—
ns
SRCK "L" Pulse Width
tWSRL
9
—
12
—
17
—
ns
RE Enable Setup Time
tRENS
0
—
0
—
0
—
ns
RE Enable Hold Time
tRENH
5
—
5
—
5
—
ns
RE Disable Setup Time
RE Disable Hold Time
tRDSS
tRDSH
0
5
—
—
0
5
—
—
0
5
—
—
ns
ns
OE Enable Setup Time
tOENS
0
—
0
—
0
—
ns
OE Enable Hold Time
OE Disable Setup Time
tOENH
tODSS
5
0
—
—
5
0
—
—
5
0
—
—
ns
ns
OE Disable Hold Time
RE "H" Pulse Width
tODSH
tWREH
5
5
—
—
5
10
—
—
5
10
—
—
ns
ns
RE "L" Pulse Width
tWREL
5
—
10
—
10
—
ns
OE "H" Pulse Width
tWOEH
5
—
10
—
10
—
ns
OE "L" Pulse Width
tWOEL
5
—
10
—
10
—
ns
RSTR Setup Time
tRSTRS
0
—
0
—
0
—
ns
RSTR Hold Time
tRSTRH
10
—
10
—
10
—
ns
SWCK Cycle Time
tSWC
25
—
30
—
40
—
ns
SRCK Cycle Time
tSRC
25
—
30
—
40
—
ns
tT
3
30
3
30
3
30
ns
Access Time from SRCK
Transition Time (Rise and Fall)
9/16
¡ Semiconductor
MSM518222A
Notes: 1. Input signal reference levels for the parameter measurement are VIH = 3.0 V and VIL
= 0 V. The transition time tT is defined to be a transition time that signal transfers
between VIH = 3.0 V and VIL = 0 V.
2. AC measurements assume tT = 3 ns.
3. Read address must have more than a 600 address delay than write address in every
cycle when asynchronous read/write is performed.
4. Read must have more than a 600 address delay than write in order to read the data
written in a current series of write cycles which has been started at last write reset
cycle: this is called "new data read".
When read has less than a 70 address delay than write, the read data are the data
written in a previous series of write cycles which had been written before the last
write reset cycle: this is called "old data read".
5. When the read address delay is between more than 71 and less than 599, read data
will be undetermined. However, normal write is achieved in this address condition.
6. Outputs are measured with a load equivalent to 1 TTL load and 30 pF.
Output reference levels are VOH = 2.4 V and VOL = 0.8 V.
10/16
¡ Semiconductor
MSM518222A
TIMING WAVEFORM
Write Cycle Timing (Write Reset)
n cycle
0 cycle
1 cycle
2 cycle
VIH
VIL
SWCK
tRSTWH
tRSTWS
tT
tWSWH
tWSWL
tSWC
VIH
VIL
RSTW
tDH
,
tDS
DIN
n-1
n
0
1
2
VIH
VIL
WE
VIH
VIL
IE
VIH
VIL
Write Cycle Timing (Write Enable)
n cycle
Disable cycle
Disable cycle
n+1 cycle
VIH
VIL
SWCK
tWENH
tWDSH
tWDSS
tWENS
VIH
VIL
WE
tWWEH
tWWEL
DIN
IE
RSTW
n-1
n
n+1
VIH
VIL
VIH
VIL
VIH
VIL
11/16
,
¡ Semiconductor
MSM518222A
Write Cycle Timing (Input Enable)
n cycle
n+1 cycle
n+2 cycle
n+3 cycle
VIH
VIL
SWCK
tIDSH
tIENH
tIDSS
tIENS
VIH
VIL
IE
tWIEH
tWIEL
n-1
DIN
n
n+3
VIH
VIL
VIH
VIL
WE
VIH
VIL
RSTW
Read Cycle Timing (Read Reset)
n cycle
0 cycle
1 cycle
2 cycle
VIH
VIL
SRCK
tT
tWSRH
tRSTRH
tRSTRS
tWSRL
tSRC
VIH
VIL
RSTR
tDDCK
tAC
DOUT
n-1
n
0
1
2
VOH
VOL
RE
VIH
VIL
OE
VIH
VIL
12/16
,
,
¡ Semiconductor
MSM518222A
Read Cycle Timing (Read Enable)
n cycle
Disable cycle
Disable cycle
n+1 cycle
VIH
VIL
SRCK
tRDSH
tRENH
tRDSS
tRENS
VIH
VIL
RE
tWREL
DOUT
tWREH
n-1
n
n+1
VOH
VOL
VIH
VIL
OE
VIH
VIL
RSTR
Read Cycle Timing (Output Enable)
n cycle
n+1 cycle
n+2 cycle
n+3 cycle
VIH
VIL
SRCK
tODSH
tOENH
tODSS
tOENS
VIH
VIL
OE
tWOEN
DOUT
RE
RSTR
n-1
n
tWOEH
tDECK
Hi-Z
n+3
VOH
VOL
VIH
VIL
VIH
VIL
13/16
¡ Semiconductor
MSM518222A
PACKAGE DIMENSIONS
(Unit : mm)
ZIP28-P-400-1.27
Mirror finish
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
1.85 TYP.
14/16
¡ Semiconductor
MSM518222A
(Unit : mm)
SOJ28-P-400-1.27
Mirror finish
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
1.30 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, TQFP, LQFP, SOJ, QFJ (PLCC), SHP, and BGA are surface mount type
packages, which are very susceptible to heat in reflow mounting and humidity absorbed in
storage. Therefore, before you perform reflow mounting, contact Oki’s responsible sales person
on the product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).
15/16
¡ Semiconductor
MSM518222A
(Unit : mm)
SOP28-P-430-1.27-K
Mirror finish
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
0.75 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, TQFP, LQFP, SOJ, QFJ (PLCC), SHP, and BGA are surface mount type
packages, which are very susceptible to heat in reflow mounting and humidity absorbed in
storage. Therefore, before you perform reflow mounting, contact Oki’s responsible sales person
on the product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).
16/16
E2Y0002-28-41
NOTICE
1.
The information contained herein can change without notice owing to product and/or
technical improvements. Before using the product, please make sure that the information
being referred to is up-to-date.
2.
The outline of action and examples for application circuits described herein have been
chosen as an explanation for the standard action and performance of the product. When
planning to use the product, please ensure that the external conditions are reflected in the
actual circuit, assembly, and program designs.
3.
When designing your product, please use our product below the specified maximum
ratings and within the specified operating ranges including, but not limited to, operating
voltage, power dissipation, and operating temperature.
4.
Oki assumes no responsibility or liability whatsoever for any failure or unusual or
unexpected operation resulting from misuse, neglect, improper installation, repair, alteration
or accident, improper handling, or unusual physical or electrical stress including, but not
limited to, exposure to parameters beyond the specified maximum ratings or operation
outside the specified operating range.
5.
Neither indemnity against nor license of a third party’s industrial and intellectual property
right, etc. is granted by us in connection with the use of the product and/or the information
and drawings contained herein. No responsibility is assumed by us for any infringement
of a third party’s right which may result from the use thereof.
6.
The products listed in this document are intended for use in general electronics equipment
for commercial applications (e.g., office automation, communication equipment,
measurement equipment, consumer electronics, etc.). These products are not authorized
for use in any system or application that requires special or enhanced quality and reliability
characteristics nor in any system or application where the failure of such system or
application may result in the loss or damage of property, or death or injury to humans.
Such applications include, but are not limited to, traffic and automotive equipment, safety
devices, aerospace equipment, nuclear power control, medical equipment, and life-support
systems.
7.
Certain products in this document may need government approval before they can be
exported to particular countries. The purchaser assumes the responsibility of determining
the legality of export of these products and will take appropriate and necessary steps at their
own expense for these.
8.
No part of the contents cotained herein may be reprinted or reproduced without our prior
permission.
9.
MS-DOS is a registered trademark of Microsoft Corporation.
Copyright 1998 Oki Electric Industry Co., Ltd.
Printed in Japan