GLUK VG_93
ZXNet echo conference «code.zx»
From Konstantin Verbov → To ALL 18 January 1998
├┤i,ALL!
I was once experimenting with
LOADER and came across a strange thing;
ORG #6000
LD A,8:CALL SEEK1
CALL RS
LD A,40
CALL SEEK
CALL RS
LD A,8:CALL SEEK1
RET
RS CALL L9; INTERRUPT #D0
LD A,#D8
CALL SEEK1; INTERRUPT #D8
RET
L9 LD A,#D0;INTERRUPTION
L10 LD C,#1F
L11 LD IX,#2A53
L12 DB #DD
L13 PUSH HL
JP #3D2F
SEEK SRL A
LD C,#7F:CALL L11
LD A,(#5D16)
RES 4,A
JR C,L15
SET 4,A
L15 AND #13:OR #2C
LD C,#FF:CALL L11
LD A,#18; POSITIONING
SEEK1 CALL L10
LD HL,#3FE5
JR L13
After starting it, the head should
first move to TR_00, then
to TR_40, then back to TR_00.
But in fact, she only goes to
TR_00, (I don’t know how long it goes
at the end of the program on TR_00), but on
TR_40, she is clearly not getting there!!!
If we now change the subroutine
"RS":
RS CALL L9
LD A,#D4; AFTER IP
CALL SEEK1
RET
This item first resets and then
sets INTRQ, but is now set
-it will be poured after arrival
index pulse.
The following program works with the old one
p/n "RS":
ORG #6000
LD A,8:CALL SEEK1
CALL RS
LD A,40
CALL SEEK
LD A,8:CALL SEEK1
RETAfter it starts, the head will move
to TR_00, and then will still go to
TR_40.
I am unable to explain this anomaly!!!
Or maybe it's just me? for this
In case I give the name of my microcircuit:
W.D.
FD 1793A-02
With best wishes, Konstantin Verbov.