---MSB CHARS. /HORIZONTAL PERIOD LSB MSB CHARACTERS
I
DATA ROW LSB ISCAN LINES/FRMI SCAN LINES/DATA ROWB8 (MSB INTIVERTI I STATUS REGISTER PEN-I RE-ILGHTI I ODD/I I FRM
• These registers are programmed with If -1.
, These registers must have these initialization values.
+
These registers may not be accessible on future UP 150 revisions and must not be written to or read from.NOTE
For a full description of the CRT Controller registers, refer to the SMC9007 data in Standard Microsystems Corporation 1982 Data Book. Use of registers noted as being not accessible on future HP 150 revisions is not recommended and such access may result in software incompatibilities with certain HP 150 units. All addresses not specifically shown are reserved and should not be used.
A description of CRT controller registers as those registers are used and supported by the UP 150 follows.
HORIZONTAL TIMING REGISTERS (RO, Rt, R2 AND R3)
These registers define the horizontal scan line timing. They must contain the (hexadecimal) values shown.
<---
one scan line--->
1<---
RO--->
173 1
<--'--- R1 ---> ! <--(RO-Rl) -->!
4F
1 11 <-R2-> 1 2E
+---+
+---ACTIVE DISPLAY 1
VLT
---+ +---+
--- --- ---- ---+
+_., .. _-------+
DOR. SYNC <--- R3 --->1
+---+
07+---Memory and I/O Mapping
VERTICAL TIMING REGISTERS (R4, R5, R 7, R8 AND R9)
These registers define the vertical frame timing. They must contain the (hexadecimal) values shown.
<--- one complete frame --->
<---
R9--->
9F
<---(R7xRB)--->
lA2D
! <-R5->
1 20
---+ +---+
VERTICAL BLANKING (NO SKEW)
DATA ROW DISPLAY TIMEI
+---+
+---+ +---+
VERT. SYNC 1
<---
R4 --->1+---+
13+---PIN CONFIGURATION/SKEW BITS REGISTER (R6)
- Contains pin configuration information ( bit 7,6 )
- Cursor skew ( bits 5,4,3 ) define the number of character clocks the cursor signal is delayed from VLT
- Blank skew ( bits 2,1,0 ) define the number of character clocks the horizontal blank component of the CBLANK signal is delayed from VLT.
- Both cursor skew and blank skew are the value "001" for the 1 character skew.
- Must contain C9 Hex.
DMA CONTROL REGISTER (RA)
- DMA disable ( bit 7). A logic "1" on this pin forces the SMC9007 DMA request into the inactive state, and the address bus will enter its high impedance state.
- DMA burst delay (bits 6,5.4). This register is loaded with "111" for zero delay. allowing all characters to be
retreived from video RAM in one burst.
- DMA Burst Count ( bits 3,2,1,0 ). Not Used.
- Must contain 70 Hex.
CONTROL REGISTER (RB)
- 7 bit register
Smooth scroll mechanism is enabled by writing a "1" to bit
6.
- Interlace, ( bits 5,4 ). "00" - non interlaced mode.
- Operation mode (bits 3,2,1 ). "000" for repetitive memory addressing.
Single/double height cursor ( bit 0 ). "1"
=
single.- Must contain 41 Hex.
TABLE START REGISTER (RC AND RD)
- These registers point to the address where the row table begins.
- The registers are set up the following way for contiguous row table mode:
*
register D ( bits 7,6 )=
"10"*
register D ( bits 5-0 )=
upper 6 bits of the 14 bit address*
register C ( bits 7-0 )=
lower 8 bits of the 14 bit address.- RC must contain 91 Hex, RD must contain 97 Hex.
AUXILIARY REGISTER 1 (RE AND RF)
- Not used, except for bits 7,6 in register F which must be
"00" for single height, single width characters.
- HE must contain FF Hex, RF must contain 3FH.
SEQUENTIAL BREAK REGISTER 1 (RIO)
- This register may not be accessible on certain HP 150 revisions and must not be used.
DATA ROW START REGISTER (Rll)
- Defines the first data row number at which a smooth scroll operation begins.
- Is initialized by the system firmware to FF Hex.
DATA ROW END REGISTER (RU)
- The row numerically one less than the row defined by this register is the last data row on which a smooth scroll will occur.
- Is initialized by the system firmt-Tal'e to FF Hex.
Memory and I/O Mapping
AUXILIARY ADDRESS REGISTER 2 (R13 AND R14)
This register may not be accessible on certain HP 150 revisions and must not be used.
START COMMAND (R15)
- During initialization of the SMC9007. after all vital screen parameters are loaded. a start command can be initiated by addressing this dummy register location.
RESET COMMAND (R16)
- This register may not be accessible on certain HP 150 revisions and must not be used.
SMOOTH SCROLL OFFSET REGISTER (R17)
- This register is loaded with the scan line offset number to allow a smooth scroll operation to occur. The offset register causes the scan line counter to start at the programmed value rather than zero for the data row that starts the smooth scroll interval.
- Must have data bit 7 (most significant) cleared (0).
VERTICAL CURSOR REGISTER (RI8)
- This register specifies the data row in which the cursor appears.
HORIZONTAL CURSOR REGISTER (R19)
- This register specifies the character position in which the cursor appears.
CURSOR REGISTERS R38 AND R39 (READ)
- These registers may not be accessible on some revisiollS of the HP 150 and must not be used.
INTERRUPT ENABLE REGISTER (RIA)
- This 3 bit write only register allows each of the 3 SMC9007 interrupts to be enabled or disabled.
- Bit 6 is set to "1" to enable vertical retrace interrupts.
- Must contain 40 Hex.
STATUS REGISTER (RlA)
- This register is only used to clear the interrupt bit. The value read is irrelevent.
VERTICAL LIGHT PEN REGISTER (RlB)
- This register may not be accessible on certain revisions ot the BP 150 and must not be used.
HORIZONTAL LIGHT PEN REGISTER (Rle)
- This register may not be accessible on certain revisions ot the BP 150 and must not be used.
VIDEO ATfRIBUTE LATCH
This latch stores 5 bits ot video data, and can be updated during the blank portions of the video trame. It is a memory mapped I/O register with the 8088 address D30BE hexadecimal. The register is actually decoded as a non-existent SMC9007 register.
VIDEO ATTRIBUTE LATCH PIN DEFINITION
+---+---+---+---+---+
I
DISPON BLRT CBLRT BLOB GREllr
+---+---+---+---+---+
D4 D3 D2 Dl DO
note: - positive logic is used ( 1
=
on, 0=
ott )- when writing to this register, D5-D7 are don't cares
DISPON BLRT
CBLRT
BLOB
GREN
Alpha Display On Character Blink Rate
Characters with BL ( blink ) enhancement set will be blanked on the screen while BLRT is a "1."
Cursor Blink Rate
The character tor which CURS from the SMC9007 is active high, the cursor will be blinked when CBLRT is a "1."
Blob Cursor Select
(otherwise double scan line cursor) Graphics Display Enable
Memory and I/O Mapping