Hercules Computer Technology GB 100 User manual

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Getti ng St arte d
What is the Hercu les Graphics Card? 1
Inventory Checklist 1
How to install the Graphics Card 2
The Graphics Card's "Software Switch" 3
HBASIC 5
2
Fo r Ad va nced Users
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Configuring the Graphics Card 8
bJj Programming 9
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Interfacing the Graphics Card
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1 ']}oubleshooting
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Register DescriptionsTable
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3 Application Notes
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Edition 2.0
Here ul es Co mputerThchnology. In c. mak es eve ry effo rt ta ens ur e t hat these d oc um ents ar e a cc urate.
Howeve
r, because we ar e always striving to improve our pr oducts, we ar e unable ta guarant ee the
a
cc uracy of the contents of these documents after the date of publication ami we di sc la im Iiability for
any changes. eITors or o
mi ssions.
No reproduction o
fthi s d oc urn ent. in any form, is allowed without the ex pr ess .... 'lit ten penni ss ion of
Hereules Computer Techno
lo gy.
'" 1984 . Here ul es Computer Th ehnology. In e. All rights ,-ese rv ed.
Here ul es Graphies Card. HBASIC ami Graph X ar e trad emarks of Hereules Co mputer Th ehnology.
IBM is a registered trad emark of Int ernational Bu s in ess Ma chines.
Print ed in the USA
1 Getting Started
What is the Hercules Graphics Card?
The Hercules Graphics Card is a high resolution graphics card for the IBM PC
monochrome display. It replaces the IBM monochrome display/ printer adapter
and is compatible with its software. The Graphics Card uses the same style
high resolution monochrome character s
et and comes with a parallel printer
interface.
The Hercules Graphics Card offers two graphics pages each with aresolution
of 720h x 348v. Software supplied with the Graphics Card allows the use of the
BASIC graphics commands. A variety of graphics applications software
compatible with
the Hercules Card is available from other vendors.
Inventory Checklist
Verify that you have received the following items:
1 Graphics Card
1 owner's manual
1 HBASIC diskette
Please
fill out the user registration card and return it to uso You will receive
our newsletter and important product information for Graphics Cards users.
If you did not receive a user registration card, then send us a postcard with
your name, address, Graphics Card serial number (which
is stamped on the
product), and the name ofyour dealer.
We strongly urge you to read this manual before you attempt to insta ll or
operate
the Hercules Graphics Card. (You may skip Chapter 2.) Ifyou en-
counter any problems when using the Graphics Card, consult Appendix 1
before contacting your dealer
or uso
1

1 Getting Started
How to Install the Graphics Card
A Follow these steps to insta ll the Graphics Card :
1 Remove the system unit cover following the
in structions
2
3
4
5
6
7
8
9
10
2
in IBM 's documentation or consult your dealer ifnecessary.
Make sure
that the IBM Monochrome Display/ Printer
Adapter or any other video board that uses the same
screen buff
er memory map is not in one ofthe expansion
slots.
Locate an empty expansion slot and ensure
that there w ill
be enough clearance under the Graphies Card onee it is
installed. (We recommend sl ot 2 in the PC anel slot 1 in
the XT.)
Remove the metal plate on the back panel ofthe system
unit opposite the slot you have chosen for the Graphics
Card.
Firmly insert the Graphics Card into the slot.
Replace the bracket screw to sec
ur e the card.
Set the switch settings on the motherboa rel for the Mono-
chrome Display or more than one monitor. (Do not count
the 64K
sc reen buffer on the Graphics Card when sett in g
the switehes for system memory.)
Make s
ur e that there is no other card in the system with
the same parallel
printer port identity LPT1:.
If your system is not an IBM PC, eo nsult the manual anel
contact the factory in case ofany diffieulties.
Run the Diagnosties program.
Import
ant: l fyou have a Hereules Graphics Card with the
model number GB100 stamped on the board, refer to Appen-
dix .4 before running the Diagnostics program.
1
Getting Started
The Graphics Card's "Software Switch"
The Hercules Graphics Card model number GB 101 comes equipped with a
"software switch." The purpose of this switch is to allow you to manipulate the
Graphics Card with software to select one of
three operating configurations.
Pay special attent i on to the information in t hi s section on setting the "software
switch." This is something
that needs to be done EACH TIME THE COM-
PUTER POWERS UP if you want to access either one 01' both "pages" of
graphics
sc reen buffer memory. If you forget to set the card into half 01' full
mod e, and you attempt to run any graphics software, your system will prob-
ably c ra sh. If this happens, do a "soft boot" (CTRL-ALT-DEL) or power up again.
The DIAG configuration is the
sta te which the card is automatically in after
power up. In this co nfiguration, the graphics capabilities are masked, a nd
th e Graphics Card emulates an IBM monochrome board for text only. No
graphics software may be run while
in this mod e.
The HALF co nfiguration makes the fir st graphics page located at BOOOO-
B7FFF accessible to graphics software. The seco nd graphics page lo cated at
B8 000 - BFFFF is suppressed allowing the pr ese nc e of other video cards
provided
that their sc reen buffer does not occ upy any portion of the first
graphics page. (This configuration allows the presence of an IBM
Co lor Card
in the system at the same time as the Hercules Graphics Card.)
The FULL configuration makes the first and seco nd graphics pages access-
ible to graphies software.
A Fo ll ow these steps to select one of the t hr ee eonfigurations:
1 'Ib select the DIAG
eo nfigur at ion , type
A> HGC DIAG [E NTER]
with the HBASIC di skette in drive A.
Alternatively, while in BASICA (not HBASIC), type
OUT &H3BF,O
Note
SYSTEM
On power up, the Graphics Card will be in the
DIAG corifiguration. Remember that it is necessary
to be in the DIAG con,tiguration before attempting
to run the Diagnostic Program. However, this is
probably the only occasion you'll want to be in this
mode.
3

1 Getting Started
2
3
4
To select the HALF configuration, type
A> HGC HAL F[ ENTER]
Alternatively, while in BASICA (not HBASIC), type
OUT &H3B F,1
SYSTEM
Note lt is necessary to be in the HALF corifiguration if
you ha ve an I BM Color Graphics Adapter in your
system and you wish
to run graphics software
utilizing thefirst graphics pag
e. (1-2-3 and Auto-
Cad require the
FULL configuration.)
To select the FULL configuration, type
A> HGC F ULL [ENTER]
Alternatively, while in BASICA (not HBASIC), type
OUT &H3BF,3
Note
SYSTEM
lt is necessary to be in FULL configuration before
running most graphics software, including Lotus
1 -2-3 and HBASIC. You may consider this to be
the normal operating conJiguration of the Graphics
Card.
Th
efi le on the HBASIC diskette ca ll ed HGC.EXE
is the. file that is accessed when you issue the
configuration command (e.g. HGC FU L L). We recom-
mend that you copy this file onto a system diskette
that you power up with.
DOS allows you to create a special batchfile
(AUTOEXEC .BAT) which is executed automati-
cally when the system boots or re
boot s. You may
.find that it is best to include the cO'Y(figuration
command (HGC FULL) in such an AUTOEXEC . BAT
file on your system diskette. (Make sure that
HGC. EXE is also on this diskette.)
Before setting the "software switch," confirm that
the program you wish to run is compatible with the
Hercules Graphics Card.
)
1 Getting Started
HBASIC
HBASIC allows you to use BASICA's graphics commands with the Hercules
Graphics Card. (The BASIC commands
that do not require the IBM Color
Card
will work without HBASIC on the Hercules Graphics Care!.)
A To use HBASIC, follow these steps:
1
2
3
4
5
Put the HBASIC diskette in drive B. (We suggest that you
write-protect your HBASIC diskette,)
'lYpe DIR B: [ENTER] .Verify that these files are on your
HBASIC diskette:
HGC . EXE
FIXD I AG . EXE
HBASIC .EX E
HBASIC1 . EXE
PATIERN . BAS
FONHOM
Copy the files on the HBASIC diskette onto your diskette or
hard
disko To do this, with the HBASIC diskette in drive B
and your diskette or hard disk
in the default drive other than
drive
B, type
COPY B: *. * [ENTER]
To run HBASIC, make sure that BASICA.COM from the
IBM DOS diskette
is also in the default drive, and make sure
that you have configured the Hercules card into its full
mode. Then type
HBASIC [ ENTER] (for DOS 2,0 or 2,1)
or HBASICl [ENTER] (for DOS 1.1 )
You can run HBASIC and HBASIC1 from any drive pro-
vided BASICA,COM
is in the default drive.
You should now see the BASIC copyright statement and the
BASIC prompt, " OK". We suggest that you run PATTERN.
BAS when you are in HBASIC to verify that HBASIC is
operating properly.
5

1
B
Getting Started
6 For advanced users: HBASIC version 2.1 supports
the
extended character set (character codes 128 to 255) provided
that the font has been loaded prior to the execution of
HBASIC. 'Ib load the font, type
A) FONT [ENTER]
While in HBASIC, you can key in these extended charac-
ters by holding down the [ ALT ] key while keying in the
decimal value of the code on the numeric keypad. In an
HBASIC program, you can invoke these characters by using
the
CHR$( )function. For example, PRINT CHR$(133) will
invoke
"a".
HBASIC FEATURES
1 HBASIC will not accept the following statements:
2
3
COLOR
SCREEN 0
SCREEN 1
WIDTH 40
HBASIC uses a character size of9 dots wide by 14 dots
tall.
BASICA uses a character size of8 x 8 dots. Be aware
ofthis difference when converting screen positions from
rows and columns
to x,y coordinates.
When you embed color specifications in a BASIC
state-
ment, they will be interpreted modulo 2. This means that
ifyour color specification is 2in a ClRC LE statement, then
the circle will be drawn black. For example:
CIRCLE(360 , 174) , 100,2" , 2/3
4 The range ofvalues ofthe screen coordinates are 0-719
horizontal from left to right, and 0-347 vertical from top
to bottom.
5 The monochrome display has an aspect ratio of2/
3. Embed
this in a CI RCLE statement to draw a round circle (see step 3.)
Also, to
draw a square, make the verticallines 2/3 as long
as the horizontallines.
6
1 Getting Started
6
7
8
HBASIC interprets slower than BASICA, so timing loops
will take longer to run.
Many people find
it helpful to know the sequence of steps
HBASIC goes through. After you type HBASIC (or HBASIC1 if
you are using DOS 1.1) the HBASIC program will load
BASICA.COM from the default drive, make some changes
to
the graphics routines in BASICA, set the screen mode to
SCREEN 2(also known as hi-res mode), and then enter the
modified
BASICA
As HBASIC runs in hi-res mode, do not use SCREEN 0or
SCREEN 1 statements. They will put you back in either text
or lo-res mode, which HBASIC is not designed to run in.
'Ib edit BASIC programs written for the IBM color card:
a Change
SCREEN 0and SCREEN 1 statements to SCREEN 2
b
c
d
e
Eliminate the
COLOR statements
Change all WI DTH 40 statements to WIDTH BO
Change the aspect ratios to 2/3
Change the x/y coordinates to compensate for the
larger monochrome screen.
7

2 For Advanced Users
Configuring the G raphi cs Ca rd
The Graphics Card uses 64K ofthe 128K IBM set aside as the PC's video
buffer. This 64K buffer
is divided into two approximately 32K buffers for
each ofthe two graphics pages.
The
printer connected to the Graphics Ca rd will serve as the system's primary
printing device (i.e. as LPT1: in DOS terminology). Any parallel port
printer
or plotter can be used with the Graphics Card, although the operation of those
printers will vary with
their control codes.
A
B
C
D
Display Buffer
Page 0 =
BOOOO-B7FFF (32K bytes)
Page 1 =
B8000-BFFFF (32K bytes)
Inpu
t/O utput Ports *
(Out)
03B4 = 6845 Index Register
(In/Out) 03B5 =
6845 Data Register
(Out) 03B8 = Display
Mode Ctri Port
(Out) 03B9 = Set Lt Pen Flip Flop
(In) 03BA = Display
Stat us Port
(Out) 03BB = Reset Lt Pen Flip Flop
(In / Out) 03BC = Printer Data Port
(In) 03BD = Printer Status Port
(InIOut) 03BE = Printer Control Port
(Out)** 03BF = Co nfiguration Switch
*Non DMA only
**Model number
GB101 has Page 1 masked off until the
Configuration Switch (03BF)
is properly set by software.
See section entitled "Programming" for details.
Int errupt Requests
IRQ7 This
interrupt is generated when the printer acknow l-
edges data. It is normally masked off until enabled via the
Printer Control Port (03BE).
Logical Devices Id
entit ies
Display = CON: (Monochrome Display)
Printer = LPTl:
8
2 For Advanced Users
Programming
The Graphics Card is a powerful too\. Exercise caution when programming
it until
yo u are familiar with its features. It is possible to damage the monitor
with improper programming.
Pay particular attention to the warning in the
sections entitled "Display Mode Control
Port" and "Configuration Switch."
A Interfacing the Graphics Card
1 Display Interface
Interface to
the monochrome display is done via the follow-
ing input/output ports which are discussed in detail below:
03
B4 6845 Index Regi ste r
03B5
6845 Data Register
03B8 Display Mode Control
Port
03BA Display Status Port
a 6845 Index and Data Registers (03B4 / 03B5)
The 6845 controls the frequencies for the mono-
chrome display and the width and height of the
screen. There are
16 parameters that govern the
display. They
are loaded into the 6845 one by one
via a single input/output port. Another output
port is used to specify which parameter will be
loaded next. These two ports
are said to be inter-
facing with the
6845 Data and Index Registers
respectively.
Description of
Parameters
Index Data
o Total characters per row inc\uding SYNC
less 1.
1 Number of visible cha ra cters per row.
2 Position ofthe first character during
SYNC, less 1.
3 Number of characters during SYNC per
row ," less 1.
4 Number ofrows less 1, inc\uding the row
during vertical retrace.
5 Number of scans (row fractions) in addi-
tion to total number ofrows. (See index
#4 above.)
9

2 For Advanced Users
10
6 Number ofvisible rows.
7 Row
number to begin the retrace, less 1.
(This will always last 16 scans.)
8 Always
output 2. (Consult 6845 data
sheet.)
9 Number ofscans per row, less 1.
10 First scan where the cursor will overlay a
character.
11 Last scan where the cursor will overlay a
character.
12 Always output O. (Consult 6845 data
sheet.)
13 Always output O. (Consult 6845 data
sheet.)
14 Offset of the cursor position in the display
buffer (H).
15 Offset of the cursor position in the display
buffer (L).
16 Offset into the buffer when lightpen
tripped (H).
17 Offset into the buffer when lightpen
tripped (L).
Note i The monochrome display requires a
scan to be approximately 54 microseconds.
ii The total number of rows and scans
must be adjusted to allow enough timefor
the screen
to be updated 50 times per
second.
iii The local oscillator on the Graphics
Card will generate a time base
of 0.5625
microseconds per character in text mode
and1 microsecond per character
in
bit-mapped mode.
iv In bit-mapped mode, one character is
16 dots wide and 4 scans tall. In text
mode, it is 9 dots wide and 14 scans tall.
v See Appendix 3 for typical parameter
values.
2 For Advanced Users
b Display Mode Control
Port (03B8)
This output port sets the mode ofoperation for the
Graphics Card.
Bit Options
o Not used
1 0 =
text mode (Power on default)
1 = graphics mode
(Note: The 6845
must be reprogrammed
each time
this bit changes value.)
2 Not used
3 0 = blank
the screen (Power on default.)
1 = activates the screen
(This
bit is useful when changing modes.
By keeping
the screen blank for aperiod
oftime, the change from text to graphics
modes can be done without any screen
bounce.)
4
Not used
5 0 =
turn off the text blinker (Power on
default.)
1 =
turn on the text blinker
(This blinker has no effect on
the cursor.
Every character whose attribute indi-
cates blinking, will now blink.)
6
Not used
7 0 =
Page 0 (Power on default. Start
display at BOOOO.)
1 = Page 1 (Start display at B8000. This
bit selects the active display buffer on the
Graphics Card.)
Note Be particularly careful when changing
between text and graphics modes. You
must simultaneously:
-program the Display Mode Control
Port bit 1, and
-program the 6845 with the proper
parameters.
When you switch between text and graphics
modes, your monitor is subject to some
11

2 For Advanced Users
c
12
undefined horizontal and vertical fre-
quencies. For this reason
we suggest
that you
do not use high levellanguages
to control the Display Mode Control Port
bit 1. (This does not include memory
access which can be done in any lan-
guage.) See Appendix 3 for a listing
of
the correct way to change modes.
Display Status Port (03BA)
This input
port is used to sense the real time
status of the monochrome display.
Bit Conditions
o
1
2
3
4
5
6
7
o= normal character
1 = SYNC (Screen is temporarily
blanked.)
Not used
Not used
o= dots off
1 = dots on
(This bit can be used as a software check-
point to verify
that the monochrome
display is receiving an active video
signal.)
Not used
Not used
Not used
o= vertical retrace (Screen is tempo-
rarily blanked.)
1 = active displ
ay. (This information is
useful when software wants to make
sure
that the screen is blanked.)
2 For Advanced Users
2 The
printer interface uses the following input/output
ports:
03BC
03BD
03BE
a
b
Printer Data Port
Printer Status Port
Printer Control Port
Printer Data Port (03BC)
An output to this port willlatch the value from
the data bus to the printer . The actual pin condi-
tions
are returned when input. This feature is
used to verify the integrity of
the data path.
Printer Status Port (03BD)
This is an input
port only.
Bit Conditions
o Not used
1
Not used
2
Not used
3 0 =
printer error
1 = normal operation
4 0 =
printer not attentive
1 = printer is listening
5 0 = normal operation
1 = out of
paper
6 0 = accepting data
1 = ready for more
7 0 =
printer is busy, not selected or in error
1 = normal operation
13

2 For Advanced Users
c
d
14
Printer Control Port (03BE)
This is an input/output port.
Bit Actions
o
1
o= strobe the printer to accept data at
the data latch
1 = release the strobe (Power
on default.)
o= auto line feed
1 = remote line feed control (Power
on
default.)
2 0 = initialize the
printer (Power on
default.)
1 = release the
printer for normal
operation
3 0 = deselect the
printer
1 = select the printer (Power on default.)
4 0 = mask off IRQ7 (Power on default.)
1 = enable IRQ7 when the printer is
ready for data
5 Not used
6 Not used
7 Not used
Configuration Switch (03BF)
This port accesses
the software switch that allows
one of
three configurations of the Graphics Card's
memory map and protects against the accidental
setting of graphics mode.
Bit
o
1
Option
o= (power on default) prevents the
setting of graphics mode (bit 1 of Display
Mode Control Port)
1 = allows the setting of graphics mode
bit (bit 1 of Display Mode Control Port)
o= (power on default) mask Page 1
(B8000-BFFFF) out of the memory map
and prevent the setting of page bit (bit 7
ofDisplay Mode Control Port)
1 = bring Page 1 (B8000-BFFFF) into
the memory map and allow the setting of
page bit (bit 7 of
Di splay Mode Control
Port)
2
B
For Advanced Users
How the Dots Are Generated: Text
In
text mode, the display buffer is used to store the character codes
and the
attrib ute codes for displayed characters. The offset of the
storage is:
BOOOO-BOFFF (4K bytes)
The
text display is 80 characters wide and 25 lines long. All the
characters are stored contiguously using up
160 bytes per line. For
each character, one byte is used for the character code and one for
the attribute.
Offset ofthe character code of a character:
= 160 * (LINE -1) + 2 *(COLUMN -1)
Offset ofthe attribute of a character:
= 160 * (LINE -1) + 2 *(COLUMN -1) + 1
where LINE is between 1 and 25
COLUMN is between 1 and 80
The Graphics Card has a hardware character generator which can
do
256 different characters specified by the character codes. The re
is an attribute decoder which can underline, reverse video, blank,
bold face, or blink any character. The character generator conforms
to the standard IBM PC character font.
The
attribute decoder follows these rules:
7 6 5 4 3 2 1 0 Attribute Codes
B 0 0 0 I 0 0
B 0 0 0 I 0 0
B 0 0 0 I 1 1
B 1 1 1 I 0 0
where I = 0 for normal body
I = 1 for bold
body.
0 Blank
1 Underline
1 Normal Display
0 Reverse Video
If the blinker is off (i. e. the display mode control port bit
5 = O)then
B = 0 for normal background
B = 1 for bold background
If the blinker is on (display mode control port bit 5 = 1)
then B = 0 for
no blink
B = 1for blinking
15

2
C
For Advanced Users
How the Dots Are Generated : Graphics
Once the Graphics Card is in the bit-mapped mode, the display
buffer can store two pages, or two screens using one bit
per dot.
These two pages can be al
ternate ly displayed.
While a page or screen is being displayed, any alteration to
the
buffer for that page will be shown on the display. For the page not
being displayed, changes to
it will be shown only when it is
selected.
The page selection is done by using bit 7 of the Display Mode Control
Port in the following manner:
ofor Page 0
1for Page 1
The buffer
area is allocated as folIows:
Page 0 =
BOOOO-B7FFF
Page 1 = BSOOO-BFFFF
The offset (into the page) ofthe byte containing dot (x,y) in each
page is:
[2000H *(Y MOD 4)] + [90 * INTEGER (Y/ 4)] +
[INT EGER (X I S) ]
and the bit in the byte that stores the dot is bit position
7 -
(X MOD S)
where x is between 0 and 719
y is between 0 and 347
EXAMPLE: The offset of (300,250) is
[2000H *(250 MOD 4)] + [90 * (INTEGER (250 /4))] +
[ INTEGER (300/S)]
= [2000H * (2)] + [90 * (62)] + (37)
= 4000H + 5617
= 4000H + 15FIH
= 55FlH
and bit position is
7 -
(300 MOD S) = 7 - (4) = 3.
16
A Appendix 1
'froubleshooting
If you encounter any problems when using the Graphics Card, pIease review
the
fo ll owing:
A
B
C
You cannot run grap hics software Wl'itten solely for the IBM Col or
Grap hi cs Adapter (e.g. Microsoft's Flig ht Simulator.) Make sure
that you have the Hercu les version of the graphics program you
would like
to run (e.g. Version lA of 1-2-3).
Make su
re that you do not have an IBM Color Graphics Adapter or
Monochrome Display/ Printer Adapter in the system at the same
time
as the Hercules Graphics Card. (This also applies to other
graphics cards which use the same screen buffer address as the
Graphics Card.)
Check these points when using
HBASIC:
1 Use the "HBASIC" fi le with DOS 2.0 or DOS 2.1 and use the
"HBASICl" file with DOS 1.1. (HBASIC does not work
with DOS 1.0.)
2 Run HBASIC in SCREEN 2mode only.
3
4
Do not used HBASIC version 1.0, 1.1 , 2.0 with a disk
emul
ator like JFORMAT.
Check your switch settings and make
sure that they are
set for the monochrome display. (See "How to Install the
Graphics Card.")
17

A Appendix 2
Regis ter Desc ription s
Bit#
o
2
3
4
5
6
7
CRTCo nt rol
(03ß8)
(Write Onl y)
Not used
+ Select
Graphic Mode
Not used
+ Ena
bl e Vid eo
Ou tput
Not used
+ Enable
Char Blink
Not used
Page #
18
CRT Sta tu s
(o3 ß A)
(R ea d Only)
+ Horizontal
Sync
Reserved
Reserved
+
Vid eo
Output
Not used
No t used
Not used
-VSync
Pri nt er D ata
(03BC)
(R
ea d/W rite)
00
D1
02
03
04
05
06
07
Prin te r Status
(03 ß D)
(R ea d Only)
Not used
Not used
Not used
-
Err or
+ Select
Status
+ Paper Out
-Ack
-
Bu sy
Prin
te r Control
(03 ßE )
(Read/ Writ e)
+Strobe
+ Auto Feed
-Initial
ize
Printer
+ Select In
+ Enable IRQ7
On -Ack
Not used
Not used
Not used
A Appendix 3
Applic ation Notes
Code segments to change modes. (Make sure that the configuration bit is set
to your requirements before at te m pt ing to change modes.)
index
cntrl
scrn...on
grph
text
port address
equ 03b4h
equ 03b8h
control codes
equ 8
equ 2
equ 20h
xdata segment public 'data'
gtable
ttable
xdata ends
db
db
db
db
db
db
35h, 2dh, 2eh,
07h
5bh,02h,57h,57h
02h,03h,00h,00h
61h,50h,52h,Ofh
19h, 06h , 19 h, 19h
02h, Odh , Obh , Och
xcode segment public 'code'
assume cs: xcode,ds: xdata
GRAPHICS MODE-programs the 6845 CRT controller for the 720 x 348
graphics mode. The active page for both writing and display is set to the
default value of page O.
ON
ENTRY: no parameters.
gmode proc near
push es
push ds
mov ax, xdata
mov ds, ax
mov al,grph
lea si,gtable
mov bx,O
mov cx,4000h
caH
setmd
19

A Appendix 3
pop
pop
ret
grnode endp
ds
es
TEXT MODE-programs the 6845 anel CRT control register to proeluce text
mode.
ON ENTRY: no parameters.
tmode proc
near
push es
push ds
mov ax, xdata
mov ds, ax
mov al,
text
lea si,ttable
mov bX,720h
mov cx,2000
ca ll setmd
pop ds
pop es
ret
tmode endp
setmd proc near
sets mode to graphics or text
depending on al
si = parameter table
cx = number ofwords to be cleared
bx = blank value
push ds
push es
push ax
push bx
push
cx
change mode but without scrTLon
mov dX,cntrl
out dX,al
20
A Appendix 3
initialize the 6845
mov aX,ds
mov eS,ax ;also point es: si
;to
parameter
;tab le
mov dX,index
mov cx,12 ;
12 parameters to
;be
output
xor ah,ah ;starting from
;reg .O
parms: mov al ,ah
out dX,al ;output register
;number
in c dx
l
oelsb
out dX,al ;output data
inc ah ;next value
dec dx
loop parms
pop cx ;clear the buffer
mov
aX,ObOOOh
cld
mov eS,ax
xor di,di
pop ax
rep stosw
sc
rTLon ,page 0
mov dX,cntrl
pop ax
add al,scrTLon
out
dX , al
pop es
pop ds
ret
setmel enelp
xcode ends
21

A Appendix 4
Mo di fying the Diagnostics Program
Ifyou have a Hercules Graphics Card model number GB 100, do not attempt
to run the IBM diagnostic program versions 1.0, 1.01, 1.0201' 1.03 without
making
the changes described below. (Diagnostics version 2.0 can be run
without modification.)
A Make a copy of the diagnostics program by formatting a blank
diskette and using the
DISKCOPY 01' COPY command described in the
DOS manual.
B Boot DOS and wait for
the A >.
e Insert the HBASIC diskette in drive A:.
D Insert your copy of the diagnostics diskette in drive B:.
E Execute the
"FIXDIAG.EXE" program on drive A: by typing
FIXDIAG [ENTER)
F To run the diagnostic program, put your modified diagnostic copy in
drive A:. Hold down
the [ ALT) , [CTRL) and [DE L)keys simultaneously
to
reset the system and start the diagnostics program.
G Consult your IBM Guide to Operations to
step through the diag-
nostics program.
22
Index
Attribute Codes 15
AUTOEXEC.BAT 4
BASICA.COM 5
Configuring the Card 3
DIAG Configuration 3
HALF Configuration 4
FULL Configuration 4
Diagnostics 2,22
Display Buffer 8
Display Interface 9
Display Mode Cntrl. 11
Display Status Port 13
DOS Versions 5,17
FIXDIAG.EXE 5,22
FONT.COM 6
Graphics Mode 16
from Assembler 21
HBASIC.EXE 5, 17
HBASICl.EXE 5, 17
HGC.EXE
4,5
IBM Color Card 3, 17
Color Card Software 7
1/0 Ports
8
Installation 2
Interrupt Requests 8
Inventory 1
Logical Device I.D. 8
Lotus 1-2-3
4,17
PATTERN.BAS 5
Printer Cntrl. Port
14,18
Printer Data Port 13,18
Printer Interface 13
Printer Status Port 13,18
Programming 9
6845 Registers 9
Text Mode 15
23

24
Limited Wa r ranty
Here ul es Compu te r1 ech nology (I -ICT) wa rr ants this Hereul es
Graphics Ca rd to be in good wo rk in g order for ape ri od of two
ye
ars fr om the d at e of purehase from HCT or an authorized
Graphics Card dealer. Sho
ul d t hi s Gr ap hics Card fa il to be in
good
wo r ki ng order at any time during the two year period,
HCT wi ll , at its option, rel >air or replace it at no additional
ch
arg e, exce pt as s et out bel ow . Replacement p art s wi ll be
either re co nditioned or ne w, and the replaced part s w ill become
the prope
rt y of HC T. T hi s li mited wa rr anty do es n ot cover
Graphics Cards damaged fr
om a cci dent, dis ast er, mi suse, abuse
or unauthorized mooific
at i on s.
Li mi te< IWa rra nty se rvice may be obtained by de liv ering t hi s
product to an authorized Grap
hi cs Ca"d d ea ler along with
Pr oo fof Purchase Date. If the prod ll ct is ma il ed to HC T, you
must o
bta in an RMA !l umber from HCT, send it freight prepaid
an
el you mll st in su re the prodllct or ass urn e the risk of loss or
damage
in transit am i you must "eturn it in its origin al shipping
co nta in er, or an eq ui valent.
A
ll ex pr ess a nd implied war ra nties fo r the Graphics Card ,
in cluding war ra nti es of merchantibility an el fi tness for a
part i cu l ar purpose, ar e limited to two y ear s from the dat e of
purchase. No wa
rr ant ies, wh ether ex pr ess or imp li ed, w ill
ap pl y after this peri od . Some sta tes do not a ll ow li mi tat ions on
how long an
im pl ied warrant y lasts, so these limitations may
n
ot ap pl y to y ou .
1
ft hi s Graphics Card is not in g ood working order, your sole
remedy sha
ll be repair or re pl acement as described above. In
no event
wi ll HCT be li able to you fo r damages arising out of
the use
or inab ili ty to use t hi s product.
So me s tat es do n ot a ll ow the exc lu sion or limit at ion ofinci-
dental or
co nseq ll ential damages for co nsumer pr odu ct s, so
these l
imi tat i on s may n ot apply to YO t! .
Her eu les Co m pu ter Th chnology
2
550 N in th Street
ße,
-k eley, CA 947 10
To rece iv e o ur free newsle tt er, send yo ur name and a ddr ess with the
serial number on yo
ur Graphi cs Card to Here ul es Co mpu te r
Tec hnology, 255 0 Ninth St. , Be rk eley, CA 94 71 0.
25