Psion Organiser II LZ/LZ64 Programming Manual: Appendix A-D

LZ/LZ64 Programming Manual Appendix A-D

Appendix A
Organiser character set

The full character set of the Organiser is shown in the table overleaf. The more common characters can obviously just be typed from the keyboard. However, there are others which do not appear on the keys. These are accessed via the OPL CHR$ function.

Printing non-keyboard characters

By supplying the CHR$ function with the appropriate number from the table overleaf, you can print out to the screen or the printer, or assign to string variables, any of the characters shown. For example, to display a question mark the instruction is:
PRINT CHR$(63)
To display a pound sign the instruction is:
PRINT CHR$(156)

Finding out the ASCII code of a keyboard character

You can find out the ASCII value of any of the characters on the keyboard at any time without looking at the table. You do this by typing the % sign followed by the character in the calculator. For example if you type %P in the calculator, the number 80 is returned.

The table on these two pages shows the characters which have the ASCII codes 32 to 255. 32 is the space character.

The codes 0 to 7 are for user-defined characters. (page A-6)

The codes 8 to 31 are for control characters. (page A-5)

Accessing ASCII values within procedures

It is often useful to access the ASCII value of a character in a procedure - for example if you want to know whether a user has typed in Y or N.

To do this you can use the % sign and the character, e.g. %Y. The example below is part of a procedure in which you are asked whether or not you want to erase something. If you type N the program stops. If you type Y another procedure called erase: is called. If you type a key other than Y or N the procedure goes to a label in order to give you another chance.

PRINT "ERASE Y/N"
label::
g%=GET
IF g%=%N OR g%=%n :STOP
ELSEIF g%=%Y OR g%=%y :erase:
ELSE GOTO label::
ENDIF

Codes for special keys

When functions such as the GET and KEY functions are used, the ASCII code for the character on the key is normally returned. The keys not in the ASCII set return these numbers:

ON/CLEAR 1

MODE 2

UP 3

DOWN 4

LEFT 5

RIGHT 6

SHIFT and DEL 7

DEL 8

EXE 13

Control characters

For the screen. the numbers 8 to 26 have special uses. They do not produce a visible character, but may be used in conjunction with the PRINT command produce the effects listed below. For example, the instruction PRINT CHR$(22) clears the 3rd line of the screen.

CHR$(8) Moves the cursor 1 character to the left.
CHR$(9) Moves the cursor to the next tab position. (Position 0 and 10 on the screen.)
CHR$(10) Moves the cursor to the next line.
CHR$(11) Moves the cursor to the top left "home" position of the display.
CHR$(12) Clears the display (equivalent to CLS).
CHR$(13) Moves the cursor to the left of the current line.
CHR$(14) Clears the top line of the display, and moves cursor to start of line.
CHR$(15) Clears the second line of the display, and moves cursor to start of line.
CHR$(16) Sounds the Organiser's buzzer.
CHR$(17) Refreshes the 1st and 2nd line.
CHR$(18) Refreshes the lst line.
CHR$(19) Refreshes the 2nd line.
CHR$(20) Refreshes the 3rd line.
CHR$(21) Refreshes the 4th line.
CHR$(22) Clears the 3rd line of the display, and moves cursor to start of line.
CHR$(23) Clears the 4th line of the display, and moves cursor to start of line.
CHR$(24) Prints dashes, like the ones above a multi-line menu, on the 2nd line. (uses UDG 2.)
CHR$(25) Prints dots, like the ones above a one-line menu, on the 3rd line. (uses UDG 2.)
CHR$(26) Clears to the end of line.

CHR$(27) to CHR$(31) are reserved.

User-defined characters

For the screen, the numbers 0 to 7 are reserved for user-defined characters. You use the UDG command to define the pattern of dots which appears when you print one of these characters with the CHR$ function.

You define each character line-by-line by a series of eight bytes, starting with the top line of the character. (From each of the eight bytes which make up the characters, only the last five bits 16 to 1 are used because the characters are only five dots across.)
16+8+4+2=30
8+4+2=14
4
8+4+2=14
16+8+4+2=30
8+4+2=14
8+2+1=11
16+8+1=25
128 64 32 16 8 4 2 1
One byte

To define the running man as character number 1, you would use the instruction below. The first number is the character number and the 8 numbers after represent each line of the character.

UDG 1,30,14,4,14,30,14,11,25

Then you can use this instruction to display the man:

PRINT CHR$(1)

The screen clock, the symbols in the top left-hand corner, and the dotted lines under and over menus, all use UDGs. So, each time they are displayed, they overwrite any UDGs you have defined. You therefore have to redefine your UDGs each time you wish to display them. This shows the UDG numbers taken up by the clock, the symbol and the underline graphics.
02           &nbs p;345671

X              12:45a
Edit   New    Run
Print  Dir    Copy
Delete
If you wish to display an underlined menu with a symbol and the clock, you have to use UDGs 0 and 2 for your symbol and the underline. The telephone logging program in Chapter 8 is an example of how to do this.
Appendix B
Technical Data
Dimensions (with protective case closed)

Length 142.0 mm
Width 78.0 mm
Depth 29.3 mm
Weight 250 grams.

Display
Four line by twenty character alphanumeric dot-matrix liquid crystal display.

Keyboard
A total of thirty six keys including editing, cursor, alphabetic, numeric, MODE and ON/CLEAR.

Microprocessor
HD6303X Crystal frequency 3.6864 Mhz.

Memory
ROM: 64K
RAM: 32K LZ, 64K LZ64
Extra EPROM 8/16/32/64/128K - from Datapaks.
Extra RAM 32K - from Rampak.

Clock
Real time clock with 32768 Hz crystal frequency source.

Datapaks

Storage medium
EPROM (Erasable, Programmable. Read Only Memory)

Data retention
'Mean time to failure' 50 years at temperatures up to 100'C

Formatting
30 minutes in Psion Formatter clears Datapak. Can be re-formatted up to 100 times

Memory capacity
8K Datapak 8192 bytes
16K Datapak 16384 bytes
32K Datapak 32768 bytes
64K Datapak 65536 bytes
128K Datapak 131072 bytes

Datapaks

Storage medium
Battery backed-up RAM.

Formatting
Format option in Utils clears Rampak.

Memory capacity
32768 bytes.

Power

Standard alkaline 9 volt long-life battery. Mains adaptor available.

Psion has a policy of continuous product development Small modifications arising from this are not necessarily reflected in this manual.

Appendix C
Technical programming

Memory addresses

These addresses are used for certain system variables. You access them with PEEKB, PEEKW, POKEB and POKEW. You should only use these commands if you you know what you are doing.
Address Default Use
$0069,$006A ($04) Horizontal scroll delay counter
$006B,$006C ($0A) Vertical scroll delay counter
$0077 ($0E) Delay before keyboard auto-repeat
$0078 ($00) Keyboard auto-repeat counter
$007C non-zero Auto-switch off flag, 0 disables
$20CB,$20CC Frame counter, increments every 50ms
$20CD,$20CE ($012C) Default number of seconds to auto-switch off
$00A4 ($00) Buzzer mute. non-zero mutes
$2099 ($F5) Border character round 2-line mode procedure.
$20C0 ($01) Length of key click. 0 is silent
$20A7 ($1F) Sets bits for workday alarms. The default is $1F - Monday to Friday:
MSB LSB 1 | F 0 0 0 1 | 1 1 1 1 Sun Sat Fri Thu Wed Tue Mon

Memory Map

The Organiser Model LZ has 64K of ROM and 32K of RAM in the following arrangement. Model LZ64 has two extra 16K RAM banks as indicated.
$FFFF
16K ROM
$C000
16K ROM
Bank 1 16K ROM
Bank 2 16K ROM
Bank 3
$8000
Language Stack

16K RAM 16K extra RAM
LZ64 only 16K extra RAM
LZ64 only
$4000
System variables
Machine Stack
System variables
$2000
7K RAM for devices
$0400
Machine registers
$0100
System variables
$0040
Machine registers
$0000

Hexadecimal numbers

To get a hexadecimal number in OPL, prefix it with a $ identifier - for example $FF is 255.

Machine language programming

The Organiser's CPU (Central Processor Unit) is the HD6303X microprocessor. This advanced processor can be programmed directly, in its own language called machine language or machine code.

Machine language programs run far faster than OPL programs and take up less memory, but they are much more difficult to write and debug. Also, a simple mistake in a machine language program can easily wipe out all of the information stored in the internal memory of the Organiser, as these programstake over full control of the chip at the heart of the machine.

To avoid this, it is wise to save all important data to a pack before testing machine language programs, so that all will not be lost if the machine loses all its data, or 'crashes'.

Appendix D
Error messages

The error messages are listed in numeric order. If you find it difficult to locate a message because you do not know the number, find what page it's on by looking it up in the index. Error trapping is covered in Chapter 7.

192 DEVICE WRITE FAIL
Usually occurs when a pack is faulty or when an attempt is made to write to a write-protected program pack. Also occurs when an attempt is made to format a Datapak rather than a Rampak in the Utils Format option or when Comms Link fails.

193 DEVICE READ FAIL
Usually occurs when a pack is faulty or when trying to copy from a copy-protected pack or when Comms Link fails.

194 BATTERY TOO LOW
The battery is low. Switch off and see Chapter 1 of the operating manual on how to change the battery.

195 INTEGER OVERFLOW
The range of numbers allowed for integer variables (-32768 to +32767) has been exceeded.

196 FILE NOT OPEN
An attempt has been made to write to or read from a file which is not open.

197 BAD PROC NAME
Occurs when an invalid procedure name is given. For instance, in New in Prog or inserted in the main menu.

198 RECORD TOO BIG
No record may exceed a total of 254 characters.

199 FILE IN USE
An attempt has been made to open a file which is already open, or to delete a file which is open.

200 READ PACK ERROR
The data in a Datapak cannot be read and the pack needs re-formatting.

201 FIELD MISMATCH
Occurs when a field variable used does not match any of those in the current file.

202 MENU TOO BIG
The string supplied to the MENU function is too large and must be shortened.

203 MISSING PROC
A procedure has been called which does not exist on any device.

204 MISSING EXTERNAL
A variable has been encountered which has not been declared in a calling procedure as a global variable and has not been declared in the current procedure as a local or global variable.

205 ARG COUNT ERR
An incorrect number of arguments has been supplied to a procedure.

206 ESCAPE
The ON/CLEAR key followed by Q has been pressed during program execution, halting that program.

207 BAD FIELD LIST
Any file must contain at least one and not more than sixteen fields. Occurs when an attempt is made to exceed these limits.

208 BAD ASSIGNMENT
An attempt has been made to assign a value to the wrong type of variable - for example by the statement a$=4.3

209 BAD LOGICAL NAME
An illegal logical name has been used: ie, not A B, C or D.

210 MISSING COMMA
A comma has been omitted from a list of items which should be delimited by commas throughout.

211 MISSING LABEL
An attempt been made to GOTO a label which does not exist in the current procedure.

212 TOO COMPLEX
Structures within a procedure have been nested too deeply. The limit is 8.

213 STRUCTURE ERR
An IF/ENDIF. WHILE/ENDWH or DO/UNTIL structure has been incorrectly nested.

214 DUPLICATE NAME
The file, procedure or variable name given is already in existence on the current device.

215 BAD ARRAY SIZE
An array has been declared with an illegal number of elements. eg GLOBAL name$(0,15)

216 BAD DECLARATION
A variable has been declared incorrectly - eg GLOBAL name$(300) - where the length of the string exceeds the maximum allowed.

217 NO PROC NAME
An externally created program file has been introduced which does not have a valid procedure name as its first line.

218 BAD NUMBER
A number which cannot be evaluated properly has been used. eg 2.3.4

219 BAD CHARACTER
A non-valid character such as ? or @ has been included in a calculation string or an expression.

220 STRING TOO LONG
A string has been produced which exceeds the space allocated with the GLOBAL or LOCAL commands. eg:
LOCAL a$(10)
A$="123456789ABCDEF"

221 MISMATCHED "
Occurs when quotation marks are not paired up correctly.

222 BAD IDENTIFIER
An incorrectly formed variable name has been used. eg name$$.

223 NAME TOO LONG
The specified file, procedure or variable name exceeds the maximum number of characters allowed: eight characters including the $ or % qualifier.

224 TYPE MISMATCH
A value has been assigned to variable of the wrong type. eg a$= 12 or a="text", or a procedure parameter has been given a value of the wrong type.

225 SUBSCRIPT ERR
An out of range subscript has been specified for an array variable eg a(0) or a(10) when the array a() has been declared as having 9 elements.

226 BAD FN ARGS
An illegal number or type of arguments has been supplied to a function. eg LOG(-1).

227 MISMATCHED ()'s
Brackets have not been paired up correctly.

228 SYNTAX ERR
A syntax error has been detected during the translation of a procedure.

229 DEVICE LOAD ERR
A program or peripheral pack has been removed during its verification by the Organiser or the pack has become corrupted.

230 DEVICE MISSING
An attempt has been made to access a device which is not present, eg a printer. When no printer is connected. the LPRINT command will produce this error.

231 BAD DEVICE CALL
Occurs if an illegal operation is requested of a device.

232 PAK NOT COPYABLE
An attempt has been made to copy a pack which is copy-protected.

233 DIRECTORY FULL
Only 110 data files are allowed on each device. An attempt has been made to create a file which exceeds this limit.

234 FILE NOT FOUND
An attempt has been made to access a file which does not exist on the specified device.

235 FILE EXISTS
An attempt has been made to create a file or procedure under a name which already exists on that device.

236 BAD FILE NAME
A file name has been specified which does not conform to the rules. (Max 8 characters, alphanumeric starting with a letter.)

237 BAD RECORD TYPE
Occurs only when running machine language programs.

238 END OF FILE
Occurs when an attempt is made to read past the end of a data file.

239 PACK FULL
An attempt has been made to write to a full Datapak.

240 UNKNOWN PACK
A pack not supported by the Organiser II has been fitted to one of the devices.

241 PACK NOT BLANK
Datapak needs formatting as data remnants are still present.

242 PACK CHANGED
Occurs when calling operating system machine language routines or when a pack is changed in the middle of a COPY.

243 BAD DEVICE NAME
A device name other than A, B or C has been used.

244 READ ONLY PACK
An attempt has been made to write to a program pack. These may be read from, but not written to.

245 WRITE PACK ERR
The Organiser cannot write data to one of the Datapaks. Try re-fitting it.

246 NO PACK
There is no Datapak fitted to the device named in an instruction such as CREATE, OPEN etc. or a pack has been removed during pack access.

247 FN ARGUMENT ERR
The wrong type of argument has been passed to a function or a user's procedure.

248 STACK UNDERFLOW
Will only occur when users machine language program destroys the Organiser's stack.

249 STACK OVERFLOW
As above.

250 NUM TO STR ERR
Only occurs when calling operating system machine language routines.

251 DIVIDE BY ZERO
An attempt has been made to divide by zero.

252 STR TO NUM ERR
A non-numeric string has been passed to the VAL function.

253 EXPONENT RANGE
A number has exceeded the exponent limit of + or -99.

254 OUT OF MEMORY
Either the internal memory of the machine is fully occupied by programs, diary entries and data files, or the current program has used up all available memory.

255 NO ALLOC CELLS
Seen only when running machine language routines which access internal buffer space.

Index

$ sign
  for hexadecimal numbers
  for string variables
  on procedure name
% sign
  for integer variables
  on procedure name
  used to access ASCII values
? character
  displaying
œ sign
  displaying

A
aborting running procedures
ABS function
  syntax and summary
ACOS function
  syntax and summary
ADDR function
  syntax and summary
  addresses in memory
AND, logical operator
  explained
APPEND command
  explained
  syntax and summary
ARG COUNT ERR
  arithmetic operators
array variables
  example integer array
ASC function
  syntax and summary
ASCII codes
  accessing with %
ASCII values, accessing
ASIN function
  syntax and summary
AT command
  syntax and summary
ATAN function
  syntax and summary

B
BACK command
  explained
  syntax and summary
BAD ARRAY SIZE error
BAD ASSIGNMENT error
BAD CHARACTER error
BAD DECLARATION error
BAD DEVICE CALL error
BAD DEVICE NAME error
BAD FIELD LIST error
BAD FILE NAME error
BAD FN ARGS error
BAD IDENTIFIER error
BAD LOGICAL NAME error
BAD NUMBER error
BAD PROC NAME error
BAD RECORD TYPE error
BATTERY TOO LOW error
BEEP command
  syntax and summary
branches
BREAK command
  explained
  syntax and summary

C
calculator memories
  as OPL variables
characters
  accessing ASCII code
  control
  printing non-key ones
  user defined
  user-defined, example
CHR$ function
  explained
  syntax and summary
Clock
  technical details
  UDGs used by
CLOCK command
  example of
  syntax and summary
CLOSE command
  explained
  Syntax and summary
CLS command
  explained
  syntax and summary
CM
  translating procedures for
COM, file extension
commas, in OPL syntax
concatenating strings
CONTINUE command
  syntax and summary
control characters
Copy
Prog menu option
COPY command
  syntax and summary
copying
  procedures
COPYW command
  file extensions for
  syntax and summary
COS function
  syntax and symmary
COUNT function
  syntax and symmary
CREATE command
  explained
  syntax and summary

E
Edit
  Prog menu option
EDIT command
  syntax and summary
editing
  procedures
ELSE statement
  syntax and summary
End
  OPL editor menu option
END OF FILE error
EOF function
  syntax and sumniary
ERASE command
  explained
  syntax and summary
erasing
  procedures
ERR function
  explained
  syntax and summary
ERR$ function
  syntax and summary
  error messages
errors
  common OPL errors
  generating for debugging
  messages
  run-time
ESCAPE error
ESCAPE ON/OFF command
  risks of
  syntax and summary
  escaping from procedures
  escaping from procedures
EXIST function
  syntax and summary
EXP function
  syntax and summary
EXPONENT RANGE error

F
FIELD MISMATCH error
fields
  field names
  field qualifiers
  handling in OPL
  input to
FILE EXISTS error
file extensions
FILE IN USE error
FILE NOT FOUND error
FILE NOT OPEN error
files, any type
  handling in OPL
Find
  OPL editor menu option
FIND function
  explained
  syntax and summary
FINDW function
  example of
  syntax and summary
FIRST command
  explained
  syntax and summary
FIX$ functions
  syntax and summary
floating point variables
  explained
  precedence in OPL
  range
  rounded down
  type conversion
FLT function
  syntax and summary
FN ARGUMENT ERR
FREE function
  syntax and summary

G
GEN$ function
  syntax and summary
GET function
  accessing ASCII codes
  explained
  numbers returned by
  syntax and summary
GET$ function
  syntax and summary
GLOBAL command
  syntax and summary
GOTO command
  explained
  syntax and summary
HEX$ function
  syntax and summary
hexadecimal numbers
Home
  OPL editor menu option
HOUR function
  syntax and summary

I
IABS function
  syntax and summary
IF/ELSEIF/ELSE/ENDIF command
  explained
  syntax and summary
INPUT command
  explained
  in example input routine
  syntax and summary
INT function
  syntax and summary
INTEGER OVERFLOW error
integer variables
  explained
  range
  type conversion
INTF function
  syntax and summary

J
jumps in procedures

K
KEY function
  numbers returned by
  syntax and summary
KEY$ function
  syntax and summary
KSTAT command
  syntax and summary

M
machine language
main menu
  running procedures from
MAX function
  syntax and summary
MEAN function
  syntax and summary
memories. calculator
  as OPL variables
memory maps
MENU TOO BIG error
messages, error
microprocessor, technical details
MID$ function
  explained
  syntax and summary
MIN function
  syntax and summary
MINUTE function
  syntax and summary
MISMATCHED " error
MISMATCHED ()'s
MISSING COMMA error
MISSING EXTERNAL error
MISSING LABEL error
MISSING PROC error
MONTH function
  syntax and summary
MONTH$ function
  syntax and summary

N
NAME TOO LONG error
names
  of procedures
  of variables
New option
NEXT command
  explained
  syntax and summary
NO ALLOC CELLS error
NO PACK error
NO PROC NAME error
NOT, logical operator
  explained
NTS, file extension
NUM TO STR ERR
NUM$ function

O
ODB, file extension
OFF command
  syntax and summary
ONERR command
  explained
  syntax and summary
OPEN command
  explained
  syntax and summary
operators
  available in OPL
  precedence in OPL
OPL, file extension
OPO, file extension
OPT, file extension
OR, logical operator
  explained
OUT OF MEMORY error

Q
question mark
displaying
Quit, Prog option
quitting running procedures
quitting running procedures
quotation marks in strings

R
RAD function
  syntax and summary
RAISE command
  explained
  syntax and summary
RANDOMIZE command
  syntax and summary
READ ONLY PACK error
READ PACK ERROR
RECORD TOO BIG error
records
  adding to file in OPL
  changing current in OPL
  erasing in OPL
  finding in OPL
RECSIZE function
  syntax and summary
REM command
  syntax and summary
RENAME command
  syntax and summary
  renaming procedures
REPT$ function
  syntax and summary
RETURN command
  syntax and summary
RETURN command (OPL)
  explained
RIGHT$ function
  explained
  syntax and summary
RND function
  syntax and summary
Run
  Prog menu option
  running procedures

S
Save
  Prog menu
saving
  procedures
SCI$ function
  syntax and summary
SECOND function
  syntax and summary
semi-colons, in OPL syntax
SIN function
  syntax and summary
Slicing strings
SPACE function
  syntax and summary
SQR function
  syntax and summary
STACK OVERFLOW error
STACK UNDERFLOW error
STD function
  syntax and summary
STOP command
  syntax and summary
STR TO NUM error
STRING TOO LONG error
string variables
  explained
strings
  concatenating
  explained
  maximum length
  quotation marks in
  slicing
STRUCTURE ERR
SUBSCRIPT error
SUM function
  syntax and summary
SYNTAX ERR
  system variables
  operations upon

T
TAN function
  syntax and summary
TOO COMPLEX error
Tran, Prog option
translating procedures
TRAP command
  explained
  syntax and summary
  trapping errors in OPL
type conversion, automatic
type conversion, string/numeric
TYPE MISMATCH error

U
UDG command
  explained
  syntax and summary
UDGs
  example program using
  example program using
  explained
UNKNOWN PACK error
UNTIL command
  syntax and summary
UPDATE command
  syntax and summary
UPPER$ function
  syntax and summary
USE command
  explained
  syntax and summary
user defined characters
  explained
user defined graphics
  example program using
USR function
  syntax and summary
USR$ function
  syntax and summary

V
VAL function
  syntax and summary
VAR function
  syntax and summary
variables
  array
  explained
  floating point
  GLOBAL v LOCAL
  int./floating pt. conversion
  integer
  names
  operations upon
  string
VIEW function
  syntax and summary

W
WEEK function
  syntax and summary
  weight of Organiser
WHILE/ENDWH command
  explained
  syntax and summary
WRITE PACK ERR

X
XP
translating procedures for
Xtran
OPL editor option

Y
YEAR function
syntax and summary

Z
Zap
OPL editor menu option

These pages should be viewed using Netscape 4.03 or Microsoft Internet Explorer 3.02 at 800x600 pixels.
	LZ Prog. Manual Chpt. 9	~ Homepage ~	Printer Manual

ON/CLEAR	1
MODE	2
UP	3
DOWN	4
LEFT	5
RIGHT	6
SHIFT and DEL	7
DEL	8
EXE	13

								16+8+4+2=30
								8+4+2=14
								4
								8+4+2=14
								16+8+4+2=30
								8+4+2=14
								8+2+1=11
								16+8+1=25
128	64	32	16	8	4	2	1
One byte

8K Datapak	8192 bytes
16K Datapak	16384 bytes
32K Datapak	32768 bytes
64K Datapak	65536 bytes
128K Datapak	131072 bytes

Address	Default	Use
$0069,$006A	($04)	Horizontal scroll delay counter
$006B,$006C	($0A)	Vertical scroll delay counter
$0077	($0E)	Delay before keyboard auto-repeat
$0078	($00)	Keyboard auto-repeat counter
$007C	non-zero	Auto-switch off flag, 0 disables
$20CB,$20CC		Frame counter, increments every 50ms
$20CD,$20CE	($012C)	Default number of seconds to auto-switch off
$00A4	($00)	Buzzer mute. non-zero mutes
$2099	($F5)	Border character round 2-line mode procedure.
$20C0	($01)	Length of key click. 0 is silent
$20A7	($1F)	Sets bits for workday alarms. The default is $1F - Monday to Friday: MSB LSB 1 \| F 0 0 0 1 \| 1 1 1 1 Sun Sat Fri Thu Wed Tue Mon

$FFFF
	16K ROM
$C000
	16K ROM Bank 1	16K ROM Bank 2	16K ROM Bank 3
$8000
	Language Stack 16K RAM	16K extra RAM LZ64 only	16K extra RAM LZ64 only
$4000
	System variables Machine Stack System variables
$2000
	7K RAM for devices
$0400
	Machine registers
$0100
	System variables
$0040
	Machine registers
$0000