IBM 5150 Hardware Reference Manual page 256

LOC OBJ LINE SOURCE
F6E5 DIE 1 4586
5Hl eX.l
; SHIFT ONLY MASK NOW. MOVING TO NEXT BASE
F6E7 73fC 4587 JNe 522 ; USE MASK BIT COMING OUT TO TERMINATE
F6E9 8BC2 4588
MOV AX.OX
; RESULT TO PARM REGISTER
F6EB 5B 4589 POP
BX
F6EC 59 4590
POP ex
j
RECOVER REGISTERS
F6ED SA
4591 POP ox
F6EE C3 4592
RET
I ALL DONE
4593
521
ENDP
4594 l-- -- ----- -- - - - - -- -- -- - - - -- --- -- ---------- --­
4595
J
HED_READ_BYTE
4596 f THIS ROUTINE WILL TAKE 2 BYTES FROM rtfE REGEN BUFFER.
4597 I COMPARE AGAINST THE CURRENT fOREGROUND COLOR. AND PLACE
4598 ; THE CQRRESPQtmING ONIOFF BIT PATTERN INTO THE CURRENT
4599 POSITION IN THE SAVE AREA
4600 ENTRY -­
4601 SI,OS :: POINTER TO REGEN AREA OF INTEREST
4602 ,BX
=
EXPANDED FOREGROUND COLOR
4603 BP
=
POINTER TO SAVE AREA
4604 , EXIT -­
4605
; SP IS INCPEMENT AFTER SAVE
4606
1------------------------------------------- ­
F6EF 4607
S23 PRoe NEAR
F6EF 8A24
4608 HOV AH. [SI
1 ;
GET FIRST BYTE
F6Fl 844401
4609 MOV AL.[SI+l1 ; GET SECOND BYTE
F6F4 6900CO 461D HOV
eX.DCODDH
; 2: BIT MASK TO TEST THE ENTRIES
F6F7 B200 4611
HOV DL.O
; RESULT REGISTER
F6F9
4612
S24:
F6F9 85Cl 4613
TEST AX.CX ; IS THIS SECTION BACKGROUHD?
F6FB F8 4614
eLe ; CLEAR CARRY IN HOPES THAT
IT
IS
F6FC 7401 4615
JZ 525
; IF ZERO. IT IS BACKGROUND
F6FE '9 4616 5Te , WASN'T,
so
SET CARRY
F6FF 0002 4617 S25:
ReL
DL,! ; MOVE THAT BIT INTO THE RESULT
F701 DlE9
4618 SHR CXol
F703 DJE9
4619 5HR CX,! , MOVE THE MASK TO THE RIGHT BY 2 BITS
F705 73F2 462.
JNe 52. ; DO IT AGAm IF MASK DIDN'T FALL OUT
F707 885600 4621 MOV
[BPl,DL ; STORE RESULT IN SAVE AREA
nOA 45 4622 It~C
BP
; ADJUST POINTER
F70B C3 4623
RET
; ALL DONE
4624 S23
ENOP
4625 ; - - -- --- - - --- ---------------- ----- ----- - -­
4626 ; V4_POSITION
4627 ; THIS ROUTINE TAKES THE CURSOR POSITION CONTAINED IN
4626 THE MEMORY LOCATION. AND COtNERTS
IT
INTO AN OFFSET
4629 I INTO THE REGEN BUFFER, ASSUMING ONE BYTE/CHAR.
4630 FOR MEDIUM RESOLUTION GRAPHICS, THE NUMBER MUST
4631 BE DOUBLED.
4632 ENTRY -- NO REGISTERS,MEMORY LOCATION CURSOR_POSH IS USED
4633 EXIT-­
4634 AX CONTAINS OFFSET INTO REGEN BUFFER
4635 ; --- ----- ------------------------ - -------­
F70C 4636 52.
PROC NEAR
FlOC A15000 4637
HOV AX.CURSOR_POSN ; GET CURRENT CURSOR
F70F
4638 GRAPH_POSH LABEL NEAR
F70F 53
4639
PU5H
BX I SAVE REGISTER
F710 8808
4640
HOV BX,AX
; SAVE A COpy OF CURRENT CURSOR
F712 8AC4 4641
HOV
AL.AH I GET ROWS TO AL
F714 F6264AOO 4642 HUl
BYTE PTR CRT_COLS
; NULTIPLY BY BYTES/COLUMN
F7l8 DIED 4643 5HL AX'! ; MULTIPLY
*
4 SINCE 4 ROWS/BYTE
F7lA DIED
4644
SHl
AXd
F71C 2AFF
4645 SUB BH,BH
; ISOLATE COLUMN VALUE
F7lE 03C3 4646
ADO AX,BX
; DETERMINE OFFsET
F720 56 4647 POP
BX
; RECOVER POINTER
F721 C3
464&
RET ; ALL DONE
4649
526
ENDP
4650
;------------------------------------------- ­
4651
4652 , THIS INTERFACE PROVIDES A TElETYPE LIKE INTERFACE TO THE
4653 VIDEO CARD. THE INPUT CHARACTER IS WRITTEN TO THE CURRENT
4654 ClJ;!SOR POSITION. AND THE CURSOR IS MOVED TO THE NEXT POSITION.
4655 IF THE CURSOR LEAVES THE LAST COLUMN OF THE FIELD, THE COLUMN
4656 IS SET TO ZERO. AND THE ROW VALUE IS INCREMENTED. IF THE ROW
4657 ROW VALUE LEAVES THE FIELD. THE CURSOR IS PLACED ON THE LAST ROW.
4658 FIRST COLUMN, AND THE ENTIRE SCREEN IS SCROLLED UP ONE LIUE.
4659 WHEN THE SCREEN IS SCROLLED UP. THE ATTRIBUTE FOR FILLING THE
4660 NEWLY BLANKED LINE IS READ FROM THE CURSOR POSITION ON THE PREVIOUS
4661 LINE BEFORE THE SCROLL. lH CHARACTER MODE. IN GRAPHICS MODE,
A-63