Vector Graphic Extended Systems Monitor User manual

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EXTENDED SYSTEMS MONITOR
Version 4.0
USERS MANUAL
Revision A
October 15, 1979
Copyright 1979 Vector Graphic Inc.

Extended Systems Monitor User' sManual
Copyright 1979 by Vector Graphic Inc.
All rights reserved.
Disclaimer
Vector Graphic makes no representations or warranties with respect to the
contents of this manual itself, even if the product it describes is covered
by a warranty or repair agreement. Further, Vector Graphic reserves the
right to revise this publication and to make changes from time to time in
the content hereof without obligation of Vector Graphic to notify any person
of such revision or changes, except when an agreement to the contrary
exists.
Revision Numbers
The
date and reVISIon of each page herein appears at the bottom of each
page. The revision letter such as A or B changes if the manual has been
improved but the product itself has not been significantly modified. The
date and revision on the Title Page corresponds to that of the page most
recently revised. When the product itself is modified significantly, the
product will get a new revision number, as shown on the manual's title page,
and the manual will revert to revision A, as if it were treating abrand new
product. THIS MANUAL SHOULD ONLY BE USED WITH THE PRODUCT(S) IDENTIFIED ON
THE TITLE PAGE.
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Extended Systems Monitor User' sManual
Section
General
TABLE OF a:Nl'mI'S
Page
[)escription. III «II ., .. 1$ 1
Table of Hex values •••••• ~ •••••••• ~ ••••••••••••••••••••••••••••• o2
Command Format
AASCII Dump ,. eoil '" .. '" • ~ III '8 Il!I 3
BJump to Bootstrap Loader
CCompare
Blocks
D Dump in Hex
E External Communications
F Find 1.'vJ<:) Bytes II!l .. 41 •• '" e .. O!ll 4
G Go to and Execute
HJump to HI Ram
I Input from a Port
JJump to Loaded DOS
K Set Breakpoints •••••••••••••••••••••••••••••••••••••••••••••• 5
LJump to 0000
M Move Memory Block
N
Non-desructive Memory Test
o Output to Port
P Program Memory ••••••••••••••••••••••••••••••••••••••••••••••• 6
QCompute Checksum
R
Register Dump
S Search for Single Byte
T Test Memory •••••••••••••••••••••••••••••••••••••••••••••••••• 7
UJump to 2800
WWide ASCII Dump
XExchange Memory Blocks
YKeyboard Echo
Z - Zero or Fill Memory •••••••••••••••••••••••••••••••••••••••••• 8
Entry Points "" 9
Video
Driver ••••••••••••••••••••••••• $ •••••••••••••••••••••••••••••• e10
Cursory X Y Positioning.e •••••••• - ••••••••• ~.~.o ..•.•.•.•..•.•.•..•... 12
Keyboard Code Conversion for Vector Graphic Keyboards •••••••••••••••• 12
Using the I/O Routines ••••••••••••••••••••••••••••••••••••••••••••••• 13
Other Useful Monitor Routines •••••••••••••••••••••••••••••••••••••••• 14
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Extended Systems Monitor User· s Manual
GmmRAL DESCRIPrICN
The Version 4.0 Monitor is a complete systems Monitor, able to support the
Flashwriter II (80 X 24) board, and the Vector Graphic Keyboard. Thus it is
recommended for· use with the Mindless Terminal. All keyboard and video I/O
can be done through the Monitor's I/O routines, freeing higher level
software from carrying a variety of versions for different hardware
configurations. since version 4. (21 does not ~rk wi th serial terminals, use
the 2.1 version for this purpose.
Version 4.0 differs from 3.1 in the f?llowing key ways:
1) Improved video driver, with anumber of additional commands that
software can use to manipulate the screen, and easier X-Y positioning.
2) A breakpoint executive command, for quick debugging.
3) Acommunications program that allows you to use a Vector Graphic system
as a dumb terminaL (Executive command "E").
4) Space to include up to 15 keyboard conversions for foreign language
keyboards.
5) Much easier to use Executive commands.
6) Control-Q no lon;er can be used to return to the Monitor Executive.
In addition to I/O, the Monitor includes an extensive command executive, a
compactly
written program designed to facilitate manipulation and display of
memory data. The "prompt" which indicates that the Moni tor Executive is
waitin; for operator entry is an asterisk (*).
There are 24 commands which are entered as a single letter followed by up to
four hexadecimal data fields. After each field is entered, a space is
automatically ouput as a prompt. Either upper or lower case alpha
characters may be used, but lower case characters will be converted to upper
case, and any non-hex characters will be ignored. Allowable hex characters
are 0-9, A-F. Address fields are four digits long; other fields are two
digits lon;. The executive is useful in debugging hardware and software,
particularly assembly language softare, because it is resident in the
system.
If a space is typed at any time during field entry, a default value of zero
is assumed for all leading zeroes. This applies to an entire field as well
as one that has been partially entered, and the cursor will advance to the
next field if required. For example, typing (SP) will have the same effect
as typing 0000; typing 1(21(21 (SP) will have the same effect as 0100.
Any command that generates a display can be temporarily halted with a space
and continued with another space. The ESCape key will abort a display or
command entry.
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Extended Systems Moni tor User' sManual
The 4.0 Monitor is located at address E000 -E7FF in new Vector Graphic
systems. If it is purchased for another location, address references in
this manual should be understood accordingly.
The hexadecimal number system may seem confusing if you are not familiar
with it, but it has become the standard of the microcomputer field and is
clearly the best system with 16 bit addresses and 8 bit data. It is usually
not necessary to convert between number systems, as this is usually done by
software (i.e. assemblers). Remembering afew values in hex should make
things easy:
HEX NUMBER
DECIMAL VALUE
JARGON BINARY BITS
A10 4
B11 4
C12 4
D13 4
E
14
4
F15 4
10 16
5
FF
255
8
100 256 1 PAGE
9
3FF 1,023
10
400
1,024 1K
11
FFF
4,095
12
1000
4,096 4K
13
4000 16,384
16K
15
8000 32,768 32K
16
FFFF
65,535
64K-l
16
The fami
liar rules
of
arithmetic
work just the same
in hex as in
decimal:
10
Hex
(trivial)
40) 400
2Rev
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Extended S:lsterns Monitor User IsManual
mMMAND FORMAT
*A <AIJll> <AOO2> -ASCII OOMP
Memory contents from ADRl through ADR2 will be displayed as ASCII
characters, or graphic symbols for values less than 20 hex. If the most
significant bit is high, reverse video is displayed. This command is useful
for examining files such as those created by the linedi tor, BASIC or the
WORD MANAGEMENT SYSTEM. ASCII strings embedded in object code are easy to
recognize.
*B - JUMP 10 BOO'1'S'1'RAP LOADER
Typing this command will cause a jt.nnp to location F800H which is the disk
bootstrap loader. This will cause the disk operating system disk to be
loaded into memory and transfer control to MOOS.
*c <AIJll> <ADR2> <Am3> - roMPARE BLOCKS
A byte-by-byte comparison will be made between the block of memory data
starting at ADRI and ending at ADR2 and a block of identical length starting
at ADR3. The differences will be printed out with the address, the byte in
the first block and the byte in the second blOCk. This command is useful to
compare two versions of a program or to verify that proms have been
programmed correctly.
*D <AIJll> <Am2> - IXJMP IN HEX
Memory contents from ADRl through ADR2 will be displayed as pairs of
hexadecimal characters. The left character in each pair represents the four
most significant bits of the memory location. The display may be halted and
interrupted as described above. The ASCII representation is displayed in a
column on
the right.
*E - EXTERNAL <XlMMUNICATIOOS
The monitor will output anything typed on the keyboard through port 4on the
Bitstreamer II I/O board or an appropriately addressed Bitstreamer I board.
Anything received on this port will be displayed on the screen. Normally a
300 baud modem would be connected 0 the serial RS 232 output from the I/O
board, and this feature allows the system to be used as a simple terminal to
communicate with a host in a full duplex mode. Operation at speeds above
300 baud requires the host to send null characters after linefeeds, so that
characters are not lost when the screen scrolls up.
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Extended Systems Monitor User' sManual
*F <ADRl> <ADR2> <BY'TEl> <BYTE2> - FIND 'J.'W) B~
This memory range from ADRI through ADR2 will be searched for the particular
code combination BYTE I BYTE 2. This is useful for locating particular
commands or jump addresses. For example, if you wish to change a control
character (say control D) in aprogram you may try FE 04, which is CPI 04
since this is a common way of testing input characters. If you wish to find
all locations that call or jump to a particular address, say C700, then
search for 00C7. There is no guarantee that each location displayed is
valid object code - it may be part of a data table, ASCII string, or second
and third bytes of a three byte instruction.
*G <ADRl> - GO TO AND EXECUTE
This command will cause ajump to ADRI to execute a program or user
subroutine. As wi th all Moni tor jump commands, the address contained on the
stack is "START" (C00B) and if the user routine at ADRI ends in "RET",
program
execution will return to the Monitor. Vi rtually unUmi ted stack
space is available (up to lK), but of course, pushing more registers on the
stack than are popped will defeat the return feature with undesirable
effects.
*8 - JUMP TO HI RAM
This command jumps to FC00 which is the start of the lK scratchpad RAM.
This is a useful area for small machine language programs.
*1 <PORr> -INIUr FROM A PORI"
Execution of this command will cause the CPU to execute an "IN PORT"
instruction and the accumulator contents immediately following this to· be
displayed. This command is useful in checking out peripheral equipment.
Only those ports used by the terminal, cassette interface, etc., will
contain interesting values. All others will read FF since the data bus will
be floating when the "IN" comITland is executed.
*J -JUMP TO LOADED .IJai
This command permits easy return to the MOOS disk operating system at 0437H,
or if not present, jump will be 0437H, which is the MOOS entry location and
is subject to change in future releases.
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Extended Systems Monitor User' sManual
*K - SET BREAKPOINTS
This command expects a 4 digit address, and will place a RESTART 7 (FF) at
that location in RAM. When that instruction is executed, which is a call to
location 8, the CPU will jump to the monitor routine that dumps the register
contents. The instruction replaced wi th FF will also be restored. Entry of
the monitor at E000 will clear the breakpoint, as will pressing the RESET
swi tch.
*M <ADRl> <:AJ:E2> <AIR3> - KJVE MFJvI)RY Bu:x::K
The data contained in memory starting,at ADR1 and ending at ADR2 is moved to
memory locations starting at ADR3. This command is useful for moving a
program from atemporary storage location to its correct address. If there
is an overlap of the two memory areas, interesting results are obtained.
For example, M6000 7BFF 6400 will cause the block of data from 6000 through
63FF to be repeated 8 times from 6000 through 7FFF, since by the time
location 6400 is read, it has been overwritten with data from 6000. This is
useful for bank programming of proms, or for creating repeating instruciton
sequences for test purposes.
*N -NCN-DESTRUCTIVE MFMRl TEST
Memory locations starting at 0000 are read and the data temporarily stored.
The memory location is then tested to see if 00 and FF can be written and
read correctly. This continues after rewriting the original data until the
first error is detected, whereupon the address is displayed followed by the
data wri tten into memory and what was read from it. This command is most
useful for checking how much memory asystem contains. For example, if the
system contains 16K of memory, 4000 00 FF should be printed, indicating that
there is no memory at address 4000. Since the test is non-destructive to
data in memory, it can be used at any time.
*0 <:Pan'> <DATA> -0l1l'PUT TO PORT
The two hex digits "DATA" are loaded into the accumulator and the instrucion
"our FORT" is executed. This command is useful for checking our peripheral
equipment. For example, if a printer is connected to I/O port 6, 0 06 41
will cause an "A" to be printed since 41 is the hex ASCII code for "A".
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Extended Systems Monitor User' sManual
The contents of 16 bytes of memory containing ADRI are displayed in both hex
and ASCII, allowing preceeding and following instructions to be viewed.
Advancing to the next instruction is accomplished by typing space or cursor
right (+-). Backspace or cursor left (...,.:..) goes backwards. The cursor up
and down
keys move to an adjacent 16 byte block.. Any hex characters typed
will replace the existing contents of RAM. After every keypress, the screen
display is refreshed by reading from memory, so the display reflects the
exact memory contents. To terminate, depress ESCAPE.
*Q <AOOIl> <ADR2> - a>MPlJ'l"E amc:xsuM;
The MOD 256 checksum of memory contents in the address range specified is
computed and displayed. This command is useful for checking proms or files
to see if anything has changed. Any source file or program written in pure
code (it does not write on itself) will have the same checksum as when it
was loaded.. While debugging assembly language programs, it is useful to be
able to verify that aprogram being debugged has not written garbage in the
source file or assembler.
*R - RffiISTER LUMP
This command will print a header identifying the Z-80 registers, and
immediately below it the contents of all the registers. The flags are
displayed with the letters Z C M E H for the zero, carry, minus, parity
even, and auxiliary or half carry flags respectively. The presence of the
letter indicates the flag is true. The contents of the memory locations
pointed to by the B, D, and H register pairs are also displayed as is the
return address on the stack.
*S <ADRl> <ADR2> <BYTE> - SEARCH FOR S:m;LE BYTE
This is similar to the "F" command, except that only one byte is searched
for instead of two. An example of the use of this command is to display all
locations in aprogram where an output to a port occurs (D3). The address
of each location will be displayed followed by "D3" and the next byte (the
port number).
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Extended Systems Monitor User1s Manual
*T <AmI> <ADR2> -TEST MFnJRY
This is an extremely useful command, especially when first setting up a
system. This command permits thorough testing of the system memory. A
portion of a 64K byte pseudorandom number sequence is written into memory
fran ADRl through ADR2, and the exact same sequence is regenerated from the
ini tial point and compared with what is read from memory. If all locations
compare, another portion of the sequence is used to repeat the test which
continues until it is interrupted. Any memory errors are displayed with the
address, what was written into memory and what was read from memory,
respectively. This information is all that is needed to pinpoint a
malfunctioning memory chip. 'Ibis test is qui te exhaustive if used for at
least 10 cycles and is far superior to incrementing or complementing tests
which may not reveal addressing problems. The only area of system memory
that cannot be tested with this routine is the few bytes required for the
stack and video flags in the vicinity of FFD0 on the 2708 PROM/RAM board.
*U -JUMP TO 2888
This command permits easy return to programs in the user application area of
MDOS.
*W <AmI> <ADR2> - WIDE ASCII OOMP
This is similar to the "A" command, but with a full screen width display.
*X <AmI> <ADR2> <ALR3> - EXa:.I.Ml3E MEMJRY BLOCKS
A block of memory from ADRl through ADR2 is exchanged with an equal length
block starting at ADR3. This command is useful in comparing the operation
of two versions of a program, or for rapid switching of portions of a
program
without destroying the original. A loaded BASIC program can be
exchanged with another if care is used to include the stack area (usually
below the top of allowed memory) •
*y -KEYBOARD ECHO
This command causes keyboard input to be echoed directly to the video driver
and can be used for demonstration purposes. An ESCape returns to the
Moni tor.
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Extended Systems Monitor Userls Manual
*Z <ADRl> <AIR2> <DATA> - ZERO CR FILL .MF.l'-DRY
The memory block from ADRI through ADR2 is filled with the byte "DATA".
This is useful for setting memory to Zero. The end of a file or assembled
program will stand out more clearly if memory is first zeroed. For test
purposes, single instructions can be executed continuously so that bus
waveforms are more easily interpreted. This is done by filling a block of
memory with a repeated instruction sequence wi th ajump to the start of the
block so that the program loops continuously.
8
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Extended Systems Monitor User' sManual
mTRY POINTS
Ajump table at the beginni n:! of the Moni tor can be used to access several
routines:
EOOO -The nonnal cold entry point to the Monitor Executive, this is ajump
to the initialization routine which clears the screen and initializes 8251
USARTS through I/O ports 3, 5, and 7. This is compatible with the
Bitstreamter I addressed startin:! at port 4 or the Bistrearner II addressed
starting at port 2. The USARTS are set for an X16 baud rate factor and
other parameters as would be used with a serial printer or extra terminal.
E003 - This is ajump to the routine which should be used for console
keyboard status test. Return with the zero flag set indicates no keyboard
input.
E006 - This is a jump to the keyboard data input which returns with the
character in the "A" register. The keyboard code conversions described
below are carried out. There is no checking for ESC key depression.
E009 - This is a jump to the video driver which displays the character in
"A" on the screen.
E00C - This is ajump to the "ESCAPE" routine which returns zero if no
input, or with the character in the "A" register if there is. Keyboard code
conversions are carried out. If the ESC key was pressed, the system returns
to the Monitor Executive.
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Extended Sy;sterns Monitor User's Manual
VIDEO DRIVER
Version 4 of the Monitor contains amore elaborate video driver than
previous versions. The purpose of the video driver is to accept a stream of
ASCII codes, and to write them into the screen memory in the proper place,
interpreting certain non printing control codes in a special way. There are
several entry points to the video driver. E009 is recommended. The
character code to be printed must be in the A register. A CALL E009 will
cause the character to be printed on the screen at the cursor position. All
registers will be preserved.
Control codes are generated by the keyboard by holding the control (CTRL)
key down while a letter key is pressed. Control codes have values between 0
and 31, and are 64 less than the codes for the corresponding upper case
letters. To demonstrate the features of the video driver, type Y after the
Monitor prompt, and any keyboard generated code will be echoed to the video
driver. The following control codes are interpreted as special functions,
while all others are ignored:
(B) HOVlE THE CURSOR
(D) CLEAR THE SCREEN AND HOME CURSOR
(E) DISPLAY THE CODE IN B REGISTER
(H) DESTRUCTIVE BACKSPACE (also BACKSPACE key)
(I)
TAB OVER TO THE NEXT 8 MULTIPLE (also TAB)
(J) LINEFEED (also LF Key)
(M) CARRIAGE RETURN (also RETURN key)
(N) TOGGLE CURSOR
(P) CLEAR TO END OF SCREEN
(Q) CLEAR TO END OF LINE
(R) CURSOR I.XWN (also t )
(T) TOGGLE REVERSE VIDEO
(U) CURSOR UP (also +)
(W) CURSOR LEFT (also -+- )
(X) CLEAR TO START OF LINE
(2) CURSOR RIGHT (also -+-)
ESC CURSOR XY POSITION LEAD-IN
Experiment with the keys. There are special keys on the keyboard to
generate some of the codes such as RETURN, TAB and linefeed (LF). If you
are using the Vector Graphic Keyboard or Mindless Terminal, there are also
keys for the cursor control and BACKSPACE. Afew of the functions are not
'self explanatory. A Control D sets the reverse video flag to normal in
addi tion to clearing the screen and homing the curso r. A Control Twill
then toggle the reverse video flag from normal to reverse and back without
printing on the screen.
HI
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Extended Systems Monitor User' sManual
In some cases it is desireable to print the sYmbol for a control code on the
screen. This can be done in assembly language programs by putting the code
for the sYmbol in the B register and calling the video driver with Control E
(05) in A. Enter the folowing machine code at FC00 and execute it to
demonstrate this feature:
at FC00 06 02 3E 05 04 CD 09 E0 CD OC E0 C3 02 FC
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Extended Systems Monitor User IsManual
a.msoR X Y POSITlOODK3
Many programs utilize random X Y positioning of the cursor. This is done by
outputting a three byte sequence to the video drivere The first code is ESC
(lBH) followed by the desired X position and Y position in hex. The top
left corner of the screen is 0, 0. The sequence IB 08 40 would cause the
cursor to move to line 8, character position 64 on the screen. This feature
can not be demonstrated using the keyboard since ESC causes a return to the
monitor.
The video driver provides an extensive range of special controls, however,
they must be incorporated into the software generating the video stream to
be meaningful. For instance a piece of software that merely echoes all
characters as they go into its input buffer will allow cursor motion on the
screen, but this will probably be meaningless to the software.
KEYBOARD CODE c:x:M1ERSlCE - VECTOR GRAPHIC KEYBOARDS
Due to limitations in the keyboard encoder chip, the [] key on Vector
Graphic keyboards is not encoded properly. The correct code is generated by
a
conversion routine in the Monitor!s CONVERT routine. The codes for
backslash and tilde are also produced by the control and control shift mode
of this key.
[] KEY CONVERSION:
MODE KEYCODE CONVERTED CODE
ASCII SYMBOL
unshifted Fl
shifted EI
control Bl
control shift Al
5B
5D
5C
7E
[
]
\
The cursor up key is also converted from 60H to ISH which is interpreted
correctly by the video driver. Room is provided in the routine for up to 15
keycode conversions. Foreign languages require additional conversions, and
versions are available for French, German, Swedish and Spanish. It is
essential that software utilize the monitor conversion routine for this
reason.
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Extended Systems Monitor User·s Manual
us~ THE I/O ROUTINES
The I/O routines in the Monitor are used as the Main System I/O in Vector
Graphic Systems. This makes software I/O independent and easily
interchangeable between systems. An example of how this is done is shown
below:
INPUT ROUTINE:
OUTPUT ROUTINE:
INPT
OUTPT
CALL E00CH
JZ INPT
RET (RETURNS WITH CHAR INPUT IN A)
JMP'E009H (CHARACTER IN A)
BREAK TEST:
CQJTL CALL
RET
E00CH
(RETURNS WITH ZERO FLAG SET IF NO
INPUT, OR CHARACTER IN A. JUMPS
TO MONITOR EXECUTIVE IF ESCAPE
INPUT. )
Note
that either the ESC key will break to the Monitor, which provides a
convenient way of transferring control from any executive such as the DOS or
BASIC to the Monitor, but necessitates the use of another character (Control
C is standard) for a single level break. The routines above are merely
given to illustrate how simple it is to use the Monitor I/O routines. Many
programs require additional instructions to move the character to be output
into the accumulator, or may require different flag conditions or
accumulator contents on return from the input and Break Test routine, but
the variations are easily implemented.
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Extended Systems Monitor User· s Manual
OTHER USEFUL MJNlTOR ROt1rINES
The Monitor contains anumber of routines that can be called by user
programs, and which will save considerable programming effort. In addition
to the keyboard input and video output described elsewhere, we have:
AHEX inputs four hex digits from the keyboard and returns the binary value
in D,E registers. A space is automatically output at the end. All
registers, except B, are used. Entry at AREO with a value of 1-3 in C will
convert that many digits. Non hex values will be ignored.
CRLF will output a carriage return ?nd line feed to the screen. The A
register is used.
SPCE will output a space to the screen. The A register is used.
RNDM returns a new random number in B,C based on the seed in B,C as it is
called. B,C Dfould not contain 0000. The pseudorandom number sequence
generated is 2 -1 entries long and is based on a software simulation of a
shift register with maximum length feedback. PSW is used.
PTAD first outputs a CRLF, then outputs the binary value in H,L as four hex
digits followed by a space. PSW used.
PT2 outputs (A) as two hex digits.
TAHEX calls AHEX twice, inputting two address fields of four hex digits.
The first value is returned in H,L; the second in D,E.
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