Dataman S4 User Manual

DATAMAN S4 MANUAL

Introduction to S4

DATAMAN S4 is a battery-powered PROM
programmer for Microsystem Designers. It can
readily be used for production programming
too.
S4 contains 128k, 256k or 512k of RAM which
retains data and configuration even when
switched off. The RAM can be downloaded
with data and manipulated either remotely from
a computer via RS232 interface or directly from
S4's keypad. S4 provides plug-in emulation for
PROMS via a 24/28/32 pin emulator lead. The
development method is that a new program
can be tried out by emulation. When it works, a
PROM can be programmed, plugged into the
system and the jobs done. Programming
facilities include EPROMS of the 27 series,
such as 2716 or 278000, also FLASH
EPROMS and most EEPROMS, including 28,
52, 55 & 98 series.

Introduction to S4 1

DATAMAN S4 MANUAL

Other devices can be programmed, such as
single-chip microprocessors, but some require
a plug-in adaptor.

Check List of Parts and Accessories

1. Dataman S4

2. Manual

3. Write Lead 2mm plug to Minihook

4. EMULead - Ribbon cable with 32 pin
DIL plug

5. LIBRARY ROM

6. Disk with Terminal Driver and Utilities

7. Mains charger

Three Year Guarantee

S4 has a back-to-base guarantee to the
original purchaser for three years from date of
purchase. All electronic parts and labor are
covered, except the batteries which are only
covered for the first year. To make a claim, first
telephone us with details of the fault. Some
problems can be fixed quickly without any
need for us to see the product. You can fit new
batteries yourself, for example. If we need to
see it, we will give you a returns number: then
you should send the product back to us directly,
quoting that number. Sending it to a dealer
usually wastes time. We aim to return repairs
in less than two working days. It helps if you
include a written description of the fault. If the
product develops a fault when it is out of
guarantee then there is a fixed repair charge.
At time of writing it is £95 plus carriage.

2 Introduction to S4

DATAMAN S4 MANUAL

Confirming that S4 works

Switch on and rotate the display thumb-wheel
away from you to its full extent, which darkens
the display. Adjust for best contrast, which
depends on viewing-angle and temperature. If
a LIBRARY program is loaded, S4 will display
the version number:

If you see this message then you may carry on
and use S4. Store the LIBRARY ROM
somewhere safe, in a piece of conductive foam.
If there is nothing in the display turn up the
contrast by rotating the thumbwheel on the left
of the display away from you to its fullest extent.
If still nothing, perhaps the battery is totally
discharged. Plug the charger in with the
RESET button depressed and hold it in for a
few seconds. When you release it you will see
a message:

Loading the LIBRARY ROM

Reloading S4's software program from
LIBRARY ROM is not something you should
need to do to a brand new product. In fact you
should never need to do it at all, except when a

Introduction to S4 3

DATAMAN S4 MANUAL

new version of the working program is to be
loaded.
The procedure is as follows: press the RESET
button by pushing the write lead plug through
the hole in the case above the ON/OFF switch.
(No force is needed - it is only a push button!)
You will see this message:

You will notice that the version of LIBRARY is
not identified, because there is no LIBRARY
program loaded. If S4 sees what it thinks is a
valid library it will ask you if you want to run it.
ESC = NO
ENTER = YES
If you do want to load a new library press ESC
then LIB.
Put your LIBRARY ROM in the socket and
press ENTER.
S4 will load the program contained in the
LIBRARY ROM. Then it will restart and run the
program. If the LIBRARY program loads
correctly, S4 will introduce it and display the
version number.
When the RESET button is pressed, S4 returns
to low-level BIOS MODE, in which it will only
program LIBRARY PROMS of the 27256
variety. It is not intended that you should use
S4 in BIOS MODE without a library loaded.

Note: In theory you will never need to load
the LIBRARY program. It will be present in

4 Introduction to S4

DATAMAN S4 MANUAL
memory when you buy your S4 and it will

remain there, because S4's memory is
permanent and continuous for both
programs and data.

The only reasons for loading a LIBRARY are to
upgrade to a new version or to reload your own
custom version of the library, with your
preferred defaults, after somebody else has
used your S4 and changed the settings.

RESET & BIOS Mode

If RESET is pressed S4 returns to a program
running in the masked ROM of the
microcontroller this is called the BIOS (Basic
Input/Output System). Whilst S4 will run in this
BIOS mode and obey most instructions, it is
not intended to be used without a LIBRARY
loaded into the TPA (Transient Program Area).
The BIOS contains subroutines which are used
to handle input and outputs - RS232, Keyboard,
Display etc. BIOS mode is used only for
development of new library programs. In BIOS
mode, S4 will only program a 27256 EPROM,
of the type used as a LIBRARY ROM.

This section is written for sake of
completeness - it is unlikely that anyone
not developing new software for S4 will
want to use the BIOS mode.

Whilst the RESET key is down and the charger
attached, charge is forced into the battery. This
gives a "Jump Start" facility for batteries which
are absolutely flat.

Introduction to S4 5

DATAMAN S4 MANUAL

S4's microprocessor and RAM have power on
all the time. When S4 is switched on, it
awakens from a SLEEP MODE and starts
operation at the address pointed to by the
Warm Start Vector (WSV). Loading and
running a library reloads the WSV so that S4
starts operation in the right place. Pressing
RESET points the WSV back into the BIOS but
it first looks at the TPA . If the program thinks it
sees a valid library, it will ask you whether you
want to run it:

ESCape will do a COLD START into the BIOS.
ENTER will run the library.
If you want to reload your LIBRARY ROM,
place it in the ZIF socket and press LIB.
The LIB key loads a program into the Transient
Program Area from 8000 to FFFF, from a ROM
in the ZIF socket. The LIBRARY ROM must be
recognized by the system as a valid library. A
ROM which does not contain a LIBRARY will
not load. The BIOS configures S4 to handle a
27256, so the LIBRARY ROM must be a

27256.

Automatic Power-down

If there is no charger connected, S4 goes to
sleep if there is no input for 30 minutes. It turns
the display off and enters a powered-down
mode. For the last 30 seconds it makes

6 Introduction to S4

DATAMAN S4 MANUAL

beeping noises. It will switch itself off at the
end of this time. If you press a key during the
beeping, power-down is prevented. No data is
lost by power-down, but you have to switch-off­and-on-again to get the power back.
If a charger is connected, S4 remains on. If the
battery runs down to the 25% point, it is
automatically recharged.
S4 also powers down when it believes that the
battery is getting too low - less than 8.4 volts.
At this level, data and program can be
preserved, but nothing else works. It warns you
first, both audibly and with a message. If the
voltage goes below 8 volts it turns off
immediately without warning. S4 cannot do
anything useful without power, except preserve
the memory contents.

The only cure is to charge the battery.

Memory Upgrade to 512K

At some point, you may wish to upgrade the
user RAM in your S4 from 1Mbit to the full
4Mbit (512K bytes). All Dataman sales offices
keep a suitable part in stock, or you may wish
to purchase it through a local memory vendor.
The correct part should be a 4Mbit (512K x 8)
low power static RAM in a 32 pin JEDEC DIL
package. We recommend fitting a part with an
access time of 100ns or less.

The upgrade procedure is simple. First switch
off then:

1. Remove the back of the case by
unscrewing the four retaining screws

Introduction to S4 7

DATAMAN S4 MANUAL

2. Remove the 1M static RAM chip from
its socket.

3. Substitute a 4M static RAM chip or
module.

4. Replace the back of the case and the
screws.

When you switch on, S4 will now tell you that
you now have 512k of memory instead of 128k.

The ZIF Socket

The ZIF (Zero-Insertion-Force) socket is used
to load new library programs into the TPA
(Transient Program Area) as already described.
The ZIF socket is also used to hold PROMS
when programming. S4 can use PROMS much
the same as a computer uses a disk-drive: they
are a permanent storage medium, which
contains programs to be loaded into system
RAM - such as the program loaded from the
LIBRARY ROM.
When the socket is not being addressed, no
power is applied to it. PROMS can be inserted
at any time, except during an operation like LIB,
LOAD, BURN, TEST, SUM or COMP, which
read the PROM. When S4 is waiting for a
command, or performing any function which
does not involve reading a PROM, the socket
is "cold" – it has no supply voltages. Even
when the socket is being addressed directly, it
is only powered-up for sufficient time to read
the data

Note: PROMS with 24 pins or 28 pins must
be inserted at the b ottom end o f the socket

8 Introduction to S4

DATAMAN S4 MANUAL
the upper pin-sockets of each side should

be empty.

Terms and Basic Concepts

The message ESC in the display means that

the ESC key was pressed during or before
execution; the previous command was not
completed or maybe not even started.

The ZIF means the Zero-Insertion-Force

socket on the front panel.

The Keypad refers to S4's 45 keys. Key repeat

is automatic, when a key is held down. The
delay after the first entry is longer than that
after subsequent entries, to prevent false
repetition. When data is being entered by
repetition, the flashing block cursor changes to
a steady underline cursor, so that progress is
easier to follow.

The Screen means the remote terminal screen.
The Display means either the terminal screen

or S4's liquid crystal.

The Keyboard refers to the remote terminal.
The LCD is S4's own Liquid Crystal Display.

Outputs are shown boxed in the text, meaning
that this is literally what you will see:

The Command Line means the display line
which starts with a prompt >.

An operation will be performed if you press
ENTER or be aborted if you press ESCape.

Introduction to S4 9

DATAMAN S4 MANUAL

ESCape Commands which are non-destructive

(do not change anything) are actioned as soon
as you press the key, without waiting for

ENTER
A Digit is always Hexadecimal - not Decimal
An Address defines one location in memory

(expressed as 5 digits)

A Parameter is a set of Digits, two for a Byte,
five for an Address
A Block means contiguous bytes of memory
from Start address to End address inclusive. If

three parameters appear the last is the

Destination address.
Backspace and space are used to edit

parameters in the command line from the
terminal keyboard, equivalent to

on the keypad. X and Y are equivalent to

.

and

ESC aborts a command, even if it is already

running. That part of the command which is
already done cannot be undone, of course.

ENTER (or RETURN) accepts a command as

seen.

ESCape or ENTER may be pressed anywhere

in the command line. If the parameters have

been altered, ENTER accepts them as seen
but ESCape restores the originals.
Where there are three parameters in the

command line they are in the following order
START, END, DESTINATION. Each parameter
is five hex digits.

and keys

10 Introduction to S4

DATAMAN S4 MANUAL

The START and END addresses normally
define the whole PROM. They can be edited to
limit the effect of functions to less than a whole
PROM.
When editing the START address, if the

keys are pressed, then the START and END
addresses will change automatically to new
boundaries.
If the START address is changed to fall outside
the current boundary then the END address
changes automatically to the end of the new
boundary.
If either the START or the END address is
moved away from the boundary, the = (equal)
sign will change to a # (not equal).
S4 refuses to accept a value for the END
address outside the current PROM size.
If the configured PROM is bigger than the
available memory, then the sign before the
DEST address will always be #. In this case it
is not possible to handle the whole PROM in
one pass. The DEST address, may be edited
with the
blocks which can be handled separately.

and keys to divide the PROM into

or

Only one set of START, END, DEST
addresses are stored and shared between
those functions which use these parameters.
Pressing the ESCape key when editing the
parameter line aborts the command, but leaves

Introduction to S4 11

DATAMAN S4 MANUAL

the START, END, DEST as seen - it does not
restore their original values.

Paged EPROMS e.g. 27513

A Page has a special meaning for EPROMS
like the 27513, which is divided into pages of
16K bytes. S4 handles page mode EPROMS
as if they had straightforward contiguous
memory. Swapping pages is handled "behind
the scenes" without troubling the user.
Thus there is no apparent difference in the way
S4 handles a 27512, which is one single block
of 64k bytes, and a 27513, which is 4 pages of
16k bytes.
The user must be aware of the real difference,
however, and how it affects his system. Use of
these devices is described in manufacturer’s
literature.

FUNC Key

The FUNC key is used like a shift key to
access an extra set of functions. When waiting
for a function the prompt becomes * instead of
>.

Audible Tones

S4 makes a variety of beeping noises:
A single tone is made on acceptance of a key.
A double tone low-high is a rebuke that a key
is not acceptable.
During the execution of those commands
which take several seconds, "pips" are emitted
every half-second to tell you that the program
is working - except in the BURN routine, which
writes addresses to the display.

12 Introduction to S4

DATAMAN S4 MANUAL

An incoming data-file makes a recognizable
sound.
The ADVANCED SETUP has variables which
can be modified to change the tones made by
the beeper.

Introduction to S4 13

DATAMAN S4 MANUAL

Computer Operation

There are two ways of using S4. The obvious
way is to enter commands by pressing keys
and reading the 80-character LCD. The other
way is to attach an RS232 interface lead and
enter commands from your computer and see
the results on the screen. There are
differences between Stand-alone and Remote
operation, but each key on S4's keypad has an
equivalent two character serial command. S4
always responds to the requesting device:
keypad commands produce responses in the
LCD, computer commands produce screen
responses. S4 will respond to either device
from the command prompt; no switching of
modes is necessary. If you disconnect the
RS232 interface during a command it may be
necessary to switch-off-and-on-again to regain
control at the keypad.
Once a function has been entered from either
the computer interface or the keypad, the other
device is ignored, until S4 returns to the
command prompt >.

14 Computer Operation

DATAMAN S4 MANUAL

Interfacing with a Computer.

Almost every S4 user will need to make a
serial link with a computer at some time.
Computers usually have a serial port, through
which file transfers can be made, in much the
same way as files can be transferred between
disks. In fact the operating system file-copying
routines can specify the serial device: MSDOS
uses COM1: or AUX:, CP/M refers to RDR:
and PUN: for example the command to transfer
a file to S4 from an IBM-type PC is:

The baud-rate, word-length, stop-bits and
parity setting must have been set previously to
the correct values. The command to do this is:

S4 must be set similarly, and the file-format
must expect, in this case, an Intel HEX file
which is decoded as it is received.
Downloading files from the operating system is
likely to work with no handshaking problems,
because S4 will receive any file at full speed.
Sending files back is often not so easy.
Computers seem to implement handshaking
properly on output, but not on input. It is
surprisingly difficult to get any information on
this subject: the manufacturer's data tells you
the names of the signals, but does not tell you
that they do not work. Experiments show that
the input buffer overflows at some point,

Computer Operation 15

DATAMAN S4 MANUAL

usually at 64K, when the system transfers the
buffer contents to disk. 64K characters is not
64K bytes, because a HEX file contains two
ASCII characters for every data byte plus
addresses, checksums and other odds and
ends. In fact it is more like 26K bytes. For small
PROMS this is enough. It is possible to send
the whole 64K as 3 chunks, then patch it
together with a word-processor and take out
the two spurious End-of-File lines.

A much better solution is to use some kind
of COMMS or TERMINAL program.

Terminal Emulating Programs.

A TERMINAL sends the information you type
at the keyboard through the serial port. It
displays what comes back through serial port
on your screen. When S4 is connected to your
computer running a terminal program, it might
seem that what you type appears on your
screen: that is not so. What your see is what
S4 chooses to send you in response:
sometimes this is what you typed: sometimes it
is not. Terminal programs usually let you send
and receive files as well, with handshaking
properly implemented, and that is all that is
required for complete control of S4.

S4 DRIVER.

Dataman supplies free terminal software for
your PC for use with S4. S4DRIVER has online
help and will work at speeds up to 115200
baud.

16 Computer Operation

DATAMAN S4 MANUAL

File Formats.

S4 sends and receives orthodox computer files.
Only a programmer with an unusual amount of
patience would wish to enter a large quantity of
code into S4 by keying it in hexadecimal
numbers. Microsystems have in the past been
developed by "hand-assembly": the translation
of microprocessor instructions into machine
code mentally without benefit of an assembler,
writing the instructions into memory in
hexadecimal using a keyboard and repetitively
trying out the program until it works. Most sane
programmers these days, who want to stay
sane, would use an assembler which permits
the entry of code as instruction-mnemonics.
The assembler creates a file of machine-code
automatically, but the file is not usually
actionable code. Actionable object code which
is placed in memory exactly as it is received is
called BINARY format. Transmission formats
usually have a certain amount of extra
information, for example the ADDRESS to start
loading the data, CHECKSUM bytes to validate
transmission etc. S4 receives files in common
formats which are output by assemblers;
formats such as INTELHEX, MOTOROLA S,
TEKHEX, ASCII or BINARY and translates
these into actionable object code which is
stored in the USER RAM.

Computer Operation 17

DATAMAN S4 MANUAL

Getting Started Quickly

A guide for those who do not want to read the
manual.

Copying an PROM

If you want to make copies of a master PROM
into blank PROMS of the same type, you must
go through four stages:

1. Configure S4 for the PROM type

2. Load the MASTER PROM into S4

3. Test that the new PROMS are blank

4. Burn the new PROMS

Configuring a PROM.

1. Place the MASTER PROM in the
socket with the notch at the top. If it
has less pins than the socket make
sure that it is at the bottom.

2. Press PROM. Choose the
manufacturer with the
Then choose the right part number
with the
when the correct part number is shown
in the display.If you have a data sheet
check that the programming voltage
shown is correct.

3. Press LOAD. S4 defaults to copying
the whole PROM into the bottom of
memory. If that is what you want press
ENTER, otherwise modify the
parameters.

4. The verify that the data has loaded
correctly press COMP. S4 will
compare the data in the PROM with

and keys. Press enter

and keys.

18 Getting Started Quickly

DATAMAN S4 MANUAL

the data you have just loaded into
RAM. If it matches you will see the
message SAME.

5. Put a fresh PROM that you want to
program into the socket. If it has a
different part number then you must
reconfigure.

6. Press TEST. S4 will report whether the
PROM can be programmed If the
message "WILL BURN" or "BLANK
PROM" appears then all is well.
Otherwise you must erase the PROM.
FLASH devices can be erased with
FUNC BURN.(press FUNC first, then
BURN). EPROMS with a window need
a dose of UV light from an eraser.

7. Press BURN, then ENTER. The
parameter line of numbers can be
modified if you do not want to burn all
of the PROM, but that is unusual. The
time taken to program the PROM
varies from a few seconds to a few
minutes.

8. It is a wise precaution to take the
checkSUM of the master PROM and
the copies. CheckSUM will help you to
identify an unlabelled PROM.

Getting Started Quickly 19

PROM KEY

DATAMAN S4 MANUAL

If you get a message on this key which says:

Then S4 will not program any PROM but

27256. You should load the library.

To configure S4 to read and program a PROM
correctly, do one of the following

1. If you remember the Ref number of the
algorithm, enter it. The number is
shown when you scroll through the
ALGORITHMS as described below.
The Ref number is not guaranteed to
be the same in different versions of the
library.

20 PROM KEY

DATAMAN S4 MANUAL

2. Use the and keys to scroll though
a list of manufacturers, and then the
and
device (At a remote terminal, use X, Y,
SPACE, BACKSPACE). You have to
know the part-number and preferably
the program-voltage of the PROM - if
you are unsure, get a data sheet from
the manufacturer. S4 will apply the
voltages shown to the PROM in the
socket - if they are incorrect the device
may be damaged. If you really must
experiment, try algorithms which apply
the lowest voltages first.

3. From the “>” prompt, press FUNC-
PROM or at the Terminal type SS. This

invokes the Silicon Signature routine,
which reads a code from the EPROM
in the ZIF socket, and selects the

correct device automatically. This is

the quickest and easiest way to
configure S4, but it should be used
with caution on older EPROMs. This

is because older EPROMS may not
have a Silicon Signature code. The
method used to read the Signature is
to raise address line 9 to 12 volts, and
then to read locations 0 & 1 of the
EPROM. Applying 12 volts to an
address line of a device that does not
have a Silicon Signature could
potentially damage the device.
However, it would be unusual for a
modern EPROM not to have a Silicon
Signature.

keys to choose the actual

PROM KEY 21

TEST KEY

DATAMAN S4 MANUAL

PRETEST (START)-(END)=(DEST)

See Glossary for the special ways of editing of
the parameter line.
PRETEST compares a PROM in the ZIF with
the contents of the USER-RAM between the
START and END addresses. The purpose is to
check whether EPROMS must be erased with
UV light prior to programming. Bits are erased
all high, and may only be programmed from
high to low. The first location which cannot be
programmed is reported. If a PROM contains
locations which are already programmed, but
the PROM will accept the new program, the

message WILL BURN is displayed If the

PROM is actually blank it contains all FF bytes

- then the message BLANK ROM is displayed.

S4 must be configured for the right type of
PROM. A warning message gives the PROM
type.
To start the PRETEST, press the ENTER key.

22 TEST KEY

DATAMAN S4 MANUAL

The example given will PRETEST a 2764,
addresses 00000 to 01FFF to see whether it
will correctly program with the contents of
USER-RAM addresses 08000 to 09FFF.

TEST KEY 23

LIB KEY

DATAMAN S4 MANUAL

LIB is used to COPY new software from a
"LIBRARY ROM" in the ZIF socket to the
Transient Program Area. The program runs
automatically when it has loaded.
When you see the message, place a LIBRARY
ROM in the front panel socket and press
ENTER. To abort the command, press
ESCape.
The LIBRARY instruction does not move all the
code in the LIBRARY ROM into the TPA area:
if it did the stack would be overwritten in the
process and the program would crash. Instead
the ROM contains pointers which show which
code must be moved. Each pointer is prefixed
by a 42 byte: 42 is used to indicate that there is
a block to be copied (Why 42? Well, any byte
could be used and 42 has no real significance,
except to the software engineer who is a

Douglas Adams fan....) The four bytes

following give START and END addresses of
the block. If there is another block then follows

24 LIB KEY

DATAMAN S4 MANUAL

another 42 byte, followed by another START
and END, and so on. When the LIBRARY
program has been loaded, S4 resets and runs
it.
At the end of the table of blocks there is a byte
which is not 42. If this byte is 00, 54 then S4
picks up the following two bytes as a start
address and executes it. If it is not 00,54 then
S4 returns to the command prompt.

LIB KEY 25

SETUP

DATAMAN S4 MANUAL

This key has no terminal equivalent. File type,
baud rate and handshake have separate
terminal commands.
The SETUP routine sets the FILE TYPE
RS232 BAUD RATE and HANDSHAKE, in that
order.
Use

and to see and select options.
It is possible to ESCape at any point but any
changes stand – the settings do not revert to
original values. Remember WYSIWIG – What
You See Is What You Get. If you read
something in the display, then it is true.
Therefore it is not necessary to proceed to set
up BAUD RATE just to change the FILE
FORMAT.

File Type.

S4 will receive files serially transmitted in a
standard format. The formats supported are
INTEL, MOTOROLA, TEKHEX, ASCII and

26 SETUP KEY

DATAMAN S4 MANUAL

BINARY. A detailed description of each format
is given later.
The
formats and set-up the one displayed. You
must leave the right format in the display –
what you see is what you get, even if you
press ESCape instead of ENTER.

and scroll through the different

Baud Rate & Handshake

Baud rates of 300, 600, 1200, 2400, 4800,
9600, 14400, 28800 or 115200 may be chosen

The

and keys scroll through the choices,
and you may use ESCape or ENTER to
complete the set-up. Auto-selection of Baud
Rate is possible too. At this point, if your
computer is running a COMMS program in
terminal mode and is attached to S4 you can
set baud-rate by pressing the SPACEBAR on
the computer's keyboard.
If handshaking on outgoing transmissions is
required, it can be set RTS or DTR.

If S4 is powered off, the handshake will be
reset to NONE when it is switched on again, if
no valid handshake can be seen. Otherwise
S4 would hang-up waiting to send the
introductory message.

SETUP KEY 27

INFO KEY

DATAMAN S4 MANUAL

This is a keypad only command: there is no
terminal equivalent.
INFO displays and continuously monitors
battery voltage and temperature, and tells you
whether the charger is connected and turned
on.

The charger normall y looks after itself an d
it needs no assistance.

S4 is powered by a rechargeable battery of 7
nickel cadmium cells providing 8.4 volts
600ma/hr. Charging is automatic: you do not
have to turn the charger on or off.
The charger turns on automatically when the
FUEL GAUGE indicates that battery is less
than 25% charged.

You do not have to switch the charger on or
off deliberately, but you can do so if you
wish in INFO mode by pressing

or .

28 INFO KEY

DATAMAN S4 MANUAL

If the charger is attached and switched on, you
will see the battery voltage rise as the battery
charges. When the battery is fully charged you
will see the temperature rise and the charger
will switch-off when the rise equals 5°C.

One CHARGE is enough. It is possible to
raise the battery temperature by charging
three or four times in succession, which
raises temperature by 5°C each time. This
does not put any extra charg e in the bat te ry
or achieve anything useful.

To terminate INFO mode, press ESCape.

Automatic Battery Charging

When S4 is turned on, it charges the battery if
the "FUEL GAUGE" shows less than 75% full.
The charger will replenish the battery in less
than an hour. There is a temperature sensor in
contact with the battery. When it sees a 5°C
rise, the charge current turns off. Charging is
thus perfectly safe and S4 may be used
normally whilst being charged.
The internal circuitry prevents the batteries
overcharging. While capacity remains they are
capable of absorbing high currents, but when
fully charged the current is not stored - it is
dissipated as heat. S4 monitors battery
temperature, looking for a 5°C rise at which
point the high current is turned off. S4 remains
on when charging - but will turn itself off
automatically when the job is done. You can
safely leave S4 alone when charging or
continue to use it. If the message HEAT
appears when charge is requested, it means

INFO KEY 29