IBM 5150 - Page 181

LoC oBJ
LINE
SOURCE
F3Ee
F3Ee aOFC04
F3EF n08
F3Fl sOFC07
F3F4 7403
F3F6 E97FOI
F3F9
F3F9 50
F3FA SI
F3F8 E6AOFF
F3FE BBFB
F400 59
F401 58
F402
F402 88166300
F406 83C206
F409
F409 EC
F40A A801
F40C 7SFB
F40E
FA
F40F
F4,OF EC
F410 A801
F412 74F8
F414 8AC3
F416 AA
F417 Fe
F418 47
F419 E2f7
F418 E9A7FD
F41E
F4lE f83100
F421 2:66A04
F424 22C4
F426 02EO
F428 SACE
F42A 02eo
F42C E996FD
F42F
F42F
50
F430 SO
F431 ESlEOO
F434 02E8
F436 22C4
F438 268A.OC
F438 58
f43C F6C380
4165 (Al) = CHAR TO WRITE
4186 IDS) == DATA SEGMENT
4187 (E5) == REGEN SEGMENT
4188 ; OUTPUT
4189 NOHE
4190 ; ------------- --------.--------------------------
4191
4192
CMP
AH,4
I
IS THIS GRAPHICS
4193
JC
Pl.
4194
CMP AH,7 IS THIS BW CARD
4195
JE
Pl.
4196
JMP
GRAPHICS_WRITE
4197 PIO:
4198 PUSH
AX I SAVE ON STACK
4199
PUSH
CX
I
SAVE WRITE COUHT
42:00
CALL
FIND_POSITION
42:01
MOV
DI,BX ; ADDRESS TO 01
4202
POP
CX J WRITE COUNT
4203
POP
ex
I BL HAS CHAR TO WRITE
4204 PH;
• WRITE_LOOP
4205
42:06
;----- WAIT FOR HORIZONTAL RETRACE
4207
4208
MOV OX , ADOR_6845
; GET BASE ADDRESS
4209
ADD DX,6
; POINT AT STATUS PORT
4210
P12:
4211
IN Al,OX
I GET STATUS
4212
TEST
Al.!
;
IS IT LOW
4213 JNZ
Pl2
I WAIT UNTIL IT IS
4214
Cll
; NO I10RE INTERRUPTS
4215
PI3:
4216
IN Al,OX
;
GET STATUS
4217
TEST
.U,l
J
IS IT HIGH
4218
JZ
P13 I WAIT UNTIL IT IS
4219 HOV
Al,Bl ; RECOVER CHAR
4220
STOSB ; PUT THE CHAR/ATTR
4221
sn
J
INTERRUPTS BACK ON
4222
INC
01
I BUMP POINTER PAST ATTRIBUTE
4223
LOOP
PH
J
AS MANY TIHES AS REQUESTED
4224
JMP VIDEO_RETURN
4225
4226
; ------ -------------------------------- -------------- ------ ------
4227 ; READ DOT -- WRITE DOT
4228 TlfESE ROUTINES WILL WRITE A DOT, OR READ THE DOT AT
4229 THE na::m:ATED LOCATION
4230 J ENTRY --
4231 OX = ROW (0-199) (THE ACTUAL VALUE DEPENDS ON THE HOOE)
4232 ex = tOLUNN ( 0-6391 1 THE VALUES ARE HOT RANGE CHECKED)
4233 AL = DOT VALUE TO WRITE (1,2 OR 4 BITS DEPENDING ON HODE,
4234 REQ'O FOR WRITE DOT ONLY, RIGHT JUSTIFIED)
4235 BIT 7 OF AL= 1 INDICATES XOR THE VALUE INTO THE LOCATION :
4236 OS = DATA SEGHENT
4237 ES = REGEN SEGMENT
4238
4239 l EXIT
4240
4241
AL = DOT VALUE READ, RIGHT JUSTIFIED, READ ONLY
1----------------------------------------------------------------
4242 ASSUNE CS:CODE,DS:DATA,ES:DATA
4243
READ_DOT PROC NEAR
4244 CALL R3 ; DETERMINE BYTE POSITION OF DOT
4245 MOV
AL,ES:[SIJ
GET THE BYTE
4246 AND
AL.AH
I HASK OFF THE OTHER BITS IN THE BYTE
4247
SHL AL,Cl I LEFT JUSTIFY THE VALUE
4248
MOV CL,DH
I
GET NUMBER OF BITS IN RESULT
4249 .OL
AL.CL
J RIGHT
JUSTIFY THE RESUlT
4250 JMP
VIDEO_RETURN
;
RETURN FROH VIDEO 10
4251
ENDP
4252
4253 WRITE_DOT PROt NEAR
4254
PUSH AX I SAVE DOT VALUE
4255
PUSH AX I TWICE
4256
CALL R3 I DETERMINE BYTE POSITION OF THE DOT
4257 SHR AL,CL I SHIFT TO SET UP THE BITS FOR OUTPUT
4258
AND AL.AH J STRIP OFF THE OTHER BITS
4259
HOV Cl.ES:(SI]
; GET THE CURRENT BYTE
4260
pop BX
I
RECOVER XOR FLAG
4261
TEST Bl.SOH
I
IS IT ON
5-88 System BIOS