Finding Z88's Version Number
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There
are three UK version numbers. To find out which one you are using
you have to do the following:- |
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- Put the Z88 in
Index.
- Press the HELP
key
- Press the Left
Arrow key
You should now see
which version number you are running.
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Magic
Numbers
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The Z88 uses an 8-bit
microprocessor. What does this mean to you? Not a lot? What should
it mean to you?
Like a mileometer
in a car that only has say eight numbers, the maximum number
you can show on it is 99999999. Add one to that number and you
will see 00000000. Although that can give you a low mileage car,
it also gives you the wrong result.
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There are two ways
you can use this `limited number'.
The first way is like
the car mileometer example where you can count POSITIVE numbers
from 00000000 to 99999999.
The second way gives
you half the numbers you had before but can use both POSITIVE
and NEGATIVE numbers. Numbers read the same but can mean different
things. Here are a few THREE DIGIT examples to show you what
I mean.
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Mileometer
No |
Positive No |
Pos
and Negative |
998 |
998 |
-002 |
999 |
999 |
-001 |
000 |
000 |
000 |
001 |
001 |
001 |
002 |
002 |
002 |
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Changing to Binary
Having only some numbers
give limitations. Unlike the THREE digit mileometer which can
give us numbers up to 999, the Z88 uses binary numbers.
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The
maximum number of an eight bit number is 256 or 127 if it uses
the positive/negative number. See Page Length Limitations in
PipeDream's bugs. |
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OZ
Gobbles Memory - Slowly
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When you start an
application, OZ - the Z88's operating system allocates some memory
for that application to run in. In an ideal world what you would
like to see is it returned to the pool of spare memory when the
application has finished with it.
This is what is supposed
to happen when you (<>KILL) the application. What does
our friend OZ do? He sometimes keeps a bit of it for himself
and looses it.
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What he has lost is
what the technocrats call `handles.' This is one reason that
you may find memory disappearing, it is not because your RAM
pack has sprung a leak. OZ has lost his handles.
You can get this memory
back by periodically saving all your files - (see Back-up) doing
a Hard Reset and
loading all your files back again. Alternatively you could try
a Soft Reset or remove an EPROM / ROM card which has been reported
to sort out handles.
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PipeDream
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Mixing up Plain
Text files with PipeDream format
If you Load a file
into PipeDream that is not the correct format you will see your
file loaded incorrectly. It is easy to fix once you know what
is wrong.
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The most common mistake
that is made is to load a `Plain Text' file into PipeDream without
loading it as a `Plain Text' file.
You will see the file
only in Column A, twelve characters wide. If this happens, load
the file again, but use the `Load as Plain Text' option set to
`Yes' this time.
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Saving a BBC BASIC program to a text file
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Load the program into BBC BASIC. Then type
[]+S
This starts writing a CLI file. Then type
LIST
This lists the program whilst writing the CLI file.
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When listing stops, stop writing the CLI file by typing
[]-S
The output has been written in
:RAM.-/S.sgn
This text file can either be loaded into PipeDream or downloaded to desktop computer.
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More Static Electricity
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Static electricity is all
around us. It does irreparable damage to low current electronic
circuits, such as those used in the Z88. It can be also responsible
for the Z88 doing a Soft Reset when you are inserting
the Mains Adapter lead.
Inserting Mains
Adapter lead
Before plugging in
the lead, do the following:-
- With your right
forefinger, touch the metallic Serial Port socket.
- With your left
hand get hold of the Mains Adapter lead and touch the metal plug.
- If you are still
alive, plug the Mains Adapter lead into the Z88.
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Sharing Same Power Source - WARNING
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It might be tempting
to run your Z88 and printer from the same power source. Using
a car or motor boat battery source for example. There are many
DC convertors that can convert from 12v to about 6.8v so in theory,
save on battery costs.
There is a major problem
with this and that is that the positive pin of the power socket
on the Z88 is connected internally to the 0v or Ground pin of
the RS-232 connector. If you connect two items that are sharing
the same power source you short out the power supply.
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This does not happen
when you are using separate mains adapters for each item because
each power source is isolated from the other. You could run one
of them from this supply but not both.
At worse you will
damage both the Z88 and the printer so DO NOT SHARE POWER SUPPLIES.
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