North Star RAM-16-A Manual page 35

0036 *
0036 *WE HAVE COMPLETED A READ AND WRITE PASS
0036 *NOW TEST BACKWARDS TO CATCH ADDRESSING ERRORS
0036
0036 69
0037 IB WBL DCX D
0038 7E
0039 12
0 03A 2C
003B C24100
003E 21ED00
WBI MOV A ,D
0041 7 A
0042 E60F
0044 B3
0045 C23700
0048 7 A
0049 C610
004B 57
004C 69
034D IB RBL DCX D
004E 46
004F 1A
0050 B8
0051 C46700
0054 2C
0055 C25B00
0058 21ED00
005B 7A RBI MOV A ,D
005C E60F
005E B3
005F C24D00
0062 0C
0063 C20400
0066 C9
*
00 67
DECR RAM PTR
MOV L ,C
BEGIN BACKWARDS WRITE
LOAD NEXT BYTE OF PATTERN
MOV A ,M
STAX D WRITE IT TO RAM
INR L STEP PATTERN PTR
SKIP IF NOT AT END OF TABLE
JNZ WBI
LXI H,PATTERN RESET PATTERN PTR
GET MSB OF PTR
END OF 4K BOUNDARY?
ANI 17Q
i i
ORA E
LOOP IF NOT AT BLOCK BEGINNING
JNZ WBL
MOV A ,D RESET PTR TO END OF BLOCK
ADI 20Q
MOV D , A
RESTORE TABLE PTR
MOV L,C
READ PASS (BACKWARDS)
PATTERN
MOV B ,M
LDAX D DATA
CMP B COMPARE
CNZ ERROR
INR L STEP TABLE PTR
JNZ RBI SKIP IF NOT AT END OF PATTERN
LXI H,PATTERN RESET PATTERN TABLE PTR
STEP RAM PTR
ANI 170 BEGIN TEST
ORA E CONTINUE TEST
JNZ RBL LOOP IF NOT AT END OF 4K
INR C CHANGE PATTERN
JNZ PASS
ALL DONE WITH TEST
RET
North Star 16K RAM Board
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