IBM 5150 Technical Reference page 128

LOC OBJ
LINE SOURCE
3.3
ROS CHECKSUM TEST I
3.4 J DESCRIPTION
3.5
A CHECKSUM IS DOHE FOR THE 8K RDS ttODULE
36. CONTAINING POO AHI) BIOS.
367
;-------------------------------------------------------­
EOAE
368 CI0:
369
; ZERO IN AL ALREADY
EOAE £6AO 370
OUT OAOH,Al ; DISABLE HHI INTERRUPTS
~
EOBO E683 371 OUT 83H,Al
; INITIAlZE DHA PAGE REG
E082 BA0803
372 MOV eX , 3DSH
fOBS EE 373
OUT
OX.Al I DISABLE COLOR VIDEO
E086 FEeD
374 INC Al
fOBS 8288 375
I10V OL,OBSH
EOBA EE
37.
OUT OX,Al ; DISABLE BIW VIDEO, EN HIGH RES
fOBS 8099
377 MeV Al.99H I SET 8255 A,t-INPUT ,S-OUTPUT
EoeD E663 378 OUT
CHO_PORT .Al I WRITE 8255 tHO/MODE REG
E06F BOFt 379
MeV
AL,OFCH
; DISABLE PARITY CHECKERS AND
fOCI E661 380
OUT PORT_B,Al
,
GATE SNS S~S.CASS MOTOR OFF
EOC3 8CC8 381
MeV
Ax.es
I SETUP S5 SEG REG
EatS 8EOO 38.
"OV
55,AX
EOC7 8E08
383 MOV OS.AX • SET UP DATA SEG TO POINT TO
. .4
I
ROH ADDRESS
385
ASSUME SS:COOE
EOC9 B7EO 38. MaV BH,OEOH J SETtJP STARTING ROS AODR (EOOOO J
EOCB BC16EO 387
MOV
SP,OFFSET Cl ; SETUP RE11.JRN ADDRESS
EOCE E97BOB
388
J"P
ROS_CHECKSUM
E001 389 Cll:
EOOI 750A 390
IN'
ERROl ; HALT SYSTEM IF ERROR
391 1---------------------------------------------------------------­
39. 8237 OMA INITIAlIZATION CHANNEl REGISTER TEST
393
I DESCRIPTION
394
DISABLE THE 8237 OMA CONTROLLER. VERIFY THAT TIMER 1
395
FUNCTIONS OK. WRITE/READ THE CUPR'ENT ADDRESS ANO WORD
39. COl.tIT REGISTERS FOR All CHAWHElS. INITIALIZE AND
397
START OMA FOR MEMORY REFRESH.
398
1---------------------------------------------------------------­
EOD3 8004 399
MOV AL,04 ; DISABLE OHA CONTROllER
EOD5 E608 400 OUT
OMA08,AL
~
401
4"
; ----- VERIFY THAT TIMER 1 FlNCTIONS OK
403
E007 8054 404
I10V AL.54H I SEL TIMER l,lSB.HOOE 2
EOD9 E643 405
OUT TIMER+3,Al
EODB 8ACI 40. tlDV
AL,CL I SET INITIAL TIMER CNT TO 0
EODO E641
407
OUT
TIMER+1,AL
EODF 408 Cl,:
i TIMERl_BITS_ON
EODF B040 40.
"OV AL.40H
I LATCH TIMER 1 COlNT
EOEI E643 410
OUT TIMER+3,Al
Eon 80F8FF
4" C"P
Bl.OFFH
I YES - SEE IF AlL BITS GO OFF
EOE6 7407
41.
J'
C13
; TIMER I_BITS_OFF
EOE8 E441
4"
IN
AL.TIMER+l
I READ TIMER 1 COlNT
EOEA OAD8 414
OR Bl,Al
; AlL BITS ON IN TIMER
EOEC E2Ft 415
lOOP
CI' I TIMER CBlTS_ON
...
EOEE F4
HlT
1 TIMER 1 FAILURE, HALT SYS
EOEF
417
en:
; TIMERl_SITS_OFF
EOEF 8AC3
418
Al,Sl
"OV ; SET TIMER 1 CNT
EOFt 28C9 419
SUB CX,CX
Eon E641
4'0
OUT
TIMER+l.AL
EOF5
4.,
C14:
; TIMER_LOOP
EOFS B040
4"
MOV
AL,40H I lATCH TIMER 1 COUNT
Eon E643
4" OUT
TIMER+3.Al
EOF9 90
"4
NOP
I DelAY FOR TIMER
EOFA 90
425 NOP
EOFB E441 4 ••
IN
Al, TIMER+l i READ TIMER 1 COUNT
EOFO 2208
4'7
'NO
BL,Al
EOFF 7403
428
JZ CIS
I GO TO WRAP_DHA_REG
EIOI E,F2
429 lOOP
CI4
i TIMER_LOOP
EI03 F4 430
HlT
; TIMER ERROR - HALT SYSTEM
~
431
432
;----- INITIALIZE TIMER 1 TO REFRESH MEMORY
4"
EI04
"4
CIS:
; WRAP_DHA_REG
EI04 BOl,
435
NOV
ALol8 I SETUP DIVISOR FOR REfRESH
E106 E641
436
OUT TIMER+I.Al
; WRITE TIMER 1 CNT REG
EI08 E60D
4"
OUT
OMA+ODH.AL ; SEtil HASTER CLEAR TO OHA
438
System BIOS 5-35