IBM 5150 Hardware Reference Manual page 252

lOC OBJ LINE SOURCE
FS6B F3 4287 REP MOVSB
; MOVE THE ODD FIELD
FS6C A4
FS6D SF 4288 POP
or
FS6E SE 4289
rop
5r
; POINTERS BACK
FS6F
C3
4290 RET ; RETURN TO CALLER
4291
R17
ENOP
4292
~
4293 ;------ CLEAR A SINGLE ROW
4294
F570 4295 R18 PROC NEAR
F570 6ACA 4296
MOV Cl,Dt
; NUMBER OF BYTES IN FIELD
F572 57 4297 PUSH
or
SAVE POINTER
F573 F3 4298 REP STOSB STORE THE ~lEW VALUE
F574 AA
FS7S SF 4299
POP
or
POINTER BACK
F576 61C70020 4300 ADO OI.2000H i POINT TO 000 FIELD
F57A 57 4301
PUSH
or
FS7B 6ACA 4302
MOV
Cl,DL
F57D F3 4303 REP STOSB FILL THE ODD
FIlElD
FS7E AA
F57F SF
4304 POP
or
FS80
C3
4305 RET ; RETURN TO CALLER
4306 Ria ENOP
4307 ; -----------------­ -­ -­ ----­ ----------------­
4308 ; GRAPHICS WRITE
4309 THIS ROUTINE WRITES THE ASCII CHARACTER TO THE CURRENT
4310 POSITION ON THE SCREEN.
4311 ENTRY -­
4312 Al
=
CHARACTER TO WRITE
4313 Bl
=
COLOR ATTRIBUTE TO BE USED FOR FOREGROUND COLOR
4314
IF BIT
7 IS SET
I
THE CHJ\R IS XOR
'0
INTO THE REGEN BUFFER
4315 (0 IS USED FOR THE BACKGROUND COLOR)
4316 CX
=
NUMBER OF CHARS TO WRITE
4317 OS
=
DATA SEGMENT
4318 ES
=
REGEN SEGMENT
4319 EXIT -­
4320 NOTHING IS RETURNED
4321
4322 GRAPHICS READ
4323 THIS ROUTINE READS THE ASCII CHARACTER AT TIiE CURRENT ClrnSOR
4324 POSITION ON THE SCREEN BY MATCHING THE DOTS ON THE SCREEN TO THE
4325 CHARACTER GENERATOR CODE POINTS
4326 ENTRY -­
4327 NONE (0 IS ASSUMED AS THE BACKGROUNO COLOR
4326 ; EXIT -­
4329 Al ; CHARACTER READ AT THAT POSITION (0 RETURNED IF NONE FOUND)
4330
4331
I
FOR BOTH ROUTINES, THE IMAGES USED TO FORM CHARS ARE CONTAINED IN ROM
4332 FOR THE 1ST 128 CHARS. TO ACCESS CHARS IN THE SECOND HALF, THE USER
4333 MUST INITIALIZE THE VECTOR AT INTERRUPT lFH (LOCATION 0007CH) TO
4334 POItn TO THE USER SUPPLIED HBlE OF GRAPHIC IMAGES (6X6 BOXESL
4335 FAILURE TO 00 SO WILL CAUSE IN STRANGE RESULTS
4336 ; ----------­ ------­ ---­ -----­ - - -­ -----------­
4337
ASSUME CS: CODE ,DS:DATA. ES : DATA
FS81 4338 GRAPHICS_~?ITE
PROC NEAR
F581 B400
4339 MOV AH,O ; ZERO TO HIGH Of CODE POINT
F583 50 4340
PUSH AX
i
SAVE CODE POINT VALUE
4341
4342 ;------ DETERMINE POSITION IN REGEN BUFFER TO PUT CODE POINTS
4343
FS84 E88501
4344
CALL S26 ; FINO LOCATION IN REGEN BUFFER
F587 8BF8 4345
MOV DI,AX
i
REGEN POINTER IN 01
4346
4347 ;------ DETERMINE REGION TO GET CODE POINTS FROM
4348
~
FS8958 4349 pOP AX RECOVER CODE POINT
F58A 3C80 4350 eMP AL,80H IS IT IN SECOND HALF
F58C 7306 4351
JAE
51
YES
4352
4353
j------
IMAGE IS IN FIRST HALF, CONTAINED IN ROM
4354
F58E BE6EFA
4355
MOV SI,OFA6EH OFFSET CRT_CHAR_GEN-OFFSET OF IMAGES
F591 OE
4356 PUSH
e5
; SAVE SEGMENT ON STACK
F592 EBOF
4357
JMP SHORT S2 ; DETERMINE_NODE
4358
A-59