IBM 5150 Hardware Reference Manual page 253

LOC OBJ
LINE SOURCE
4359
j------
IMAGE IS IN SECOND HALF. IN USER RAM
4360
F594
4361 51:
F594 2e60
4362
SUB AL.SOH
j
ZERO ORIGIN FOR SECOND HALF
F596 1E
4363
PUSH OS
SAVE DATA POINTER
F597 28F6
4364
SUB SI.SI
F599 BEDE
4365
tIDV OS.SI ESTABLISH VECTOR ADDRESSING
4366
ASSUME OS:ABSO
F598 C5367COO
4367
LOS SI.EXT_PTR
GET THE OFFSET OF THE TABLE
F59F BCDA 4368
MOV OX.OS
GET THE SEGMENT OF THE TABLE
4369 ASSUME OS : DATA
F5Al IF
4370
POP OS
; RECOVER DATA SEGMENT
F5AZ S2
4371 PUSH OX
l SAVE TABLE SEGMENT ON STACK
4372
4373 ; ----- ­ DETERMINE GRAPHICS MODE IN OPERATION
4374
F5A3
4375
52 :
; DETERMINE_MODE
FSA3 OlEO
4376
SAL AX,! I tlULTIPLY CODE POINT
F5A5 OlEO
43n
SAL
AX,! ; VALUE BY 8
F5A7 OlEO
4378
SAL AX.!
F5A9 03FO
4379
ADD
SI.AX ; SI HAS OFFSET OF DESIRED CODES
F5AB 803£490006
4380 CMP
CRT_MOOE.6
F580 IF 4381
POP DS
j
RECOVER TABLE POIHTER SEGMEHT
F581 7:2C
4382 JC 57
; TEST FOR MEDIUM RESOLUTIOH MODE
4383
4384
1------
HIGH RESOLUTION MODE
F5B3 43~5 S3:
j
HIGH_CHAR
F583 57
4381:>
PUSH ['II
j.
SAVE REGEN POINTER
F584 56
4387 PUSH
51 ; SAVE CODE POINTER
FSB5 6604
"388
MOV
OH,4 ; HUl'18ER OF TIMES THROUGH LOOP
F587
4389
54:
F587 At 4390
Loose
; GET eYTE fROM CODE POINTS
F586 F6C360
4391 TEST eL,S"1-I
; SHOULD WE USE TKE FUNCTION
F5BB 7516 4392­ JNl 56
; TO PUT CHAR IN
F580 AA
4393
STOSB STORE IN REGEN BUFFER
F58E AC 4394
Loose
F5SF
4395
$5:
F5BF 266885FFIF 4396 MOV ES: (DI+2000H-l
J
.AL ; StORE IN SECONO HALF
F5C4 83C74F
4397 ADD
01.79
j
MOVE TO NEXT ROW IN REGEN
F5C7 FEtE 4398 DEC DH
j
DONE WITH LOOP
F5C9 75EC 4399 JNZ
54
F5CB 5£
4400
POP
51
F5CC SF 4401
POP
01
; RECOVER REGEN POINTER
FSCD 47 4402
INC 01 ; POINT TO NEXT CHAR POSITION
FSCE EtEl 4403
LOOP S3
j
MORE CHARS TO WRITE
F500 £9F4F8 4404
JMP
4405
F503
4406 56:
F503 263205 4407 XOR AL.E5:tOIJ i EXCLUSIVE OR WITH CURRENT
F506 AA 4408
STOSB ; STORE THE CODE POINT
F507 At
4409 LeDse ; AGAIN FOR ODD FIELD
F508 263285FFIf 4410
XOR AL.ES:IOl+2000H-ll
F50D EBED 4411 JMP
55
; BACK TO MAINSTREAM
4412
4413 ; -----­ MEDIUM RESOLUTION WRITE
F50F 4414
S7:
F5DF 6A03 4415 MOV OL.eL ; SAVE HIGH COLOR BIT
F5£1 D1E7 4416 SAl 01,1 ; OFFSET*2 SINCE 2 BYTES/CHAR
F5E3 £80100 4417 CALL 519 ; EXPAND BL TO FULL WORD OF COLOR
F5£6 4418
S8:
; MEO_CHAR
F5£6 57 4419 PUSH 01 ; SAVE REGEN POINTER
FSE7 56 4420 pUSH SI
j
SAVE THE CODE POINTER
F5£6 6604 4421
HOV OH.4
; NUMBER OF LOOPS
F5EA 4422
59:
F5EA At 4423 Loose
j
GET CODE POINT
F5EB £80EOO 4424 CALL 521 ; DOUBLE UP ALL THE BITS
F5EE 23C3 4425
AND
AX.BX
; CONVERT THEH TO FOREGROUNl) COLOR ( 0 BACK
J
F5FO F6C280
4426 TEST oL,BOH ; IS THIS XOR FUNCTION
F5F3 7407
4427 JZ 510 ; NO, STORE IT IN AS IT IS
F5F5 263225
4428 XOR AH,ES:tDIJ ; DO FUNCTION WITH HALF
F5F8 26324501 4429 XOR AL,ES:IDI+ll ; AND WITH OTHER HALF
FSFC
4430
S10:
,
F5FC 268825
4431
MOV ES:[OIJ.AH I STORE FIRST BYTE
F5FF 26884501
4432 MOV ES;[oI+1J,AL ; STORE SECOND BYTE
F603 AC 4433 LOOSS ; GET CODE POUlT
F604 E8t500
4434
CALL 521
A-60