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SEP DATAl
6B pin 6
READ BIT· SHIFT
2A pin 15
SAVED READ DATA
9G pin 9
READ SHIFT REG
SE pins 3,4,5,6
10,11,12,13
always high
.Sus pulse every 8us
.Suspulse every 7.Sus
.Sus pulse every 8us
always low
8us period square wave
always low
always high
6. This step checks-out the timing signals for reading and·
writing.
For this step the drive should have its power on and
the ribbon cable should be connected between drive and
controller.
The following program (valid for standard version
only) should be entered into memory and run starting at
address 2000 hex.
19
21000
20103
2006
2008
200B
200E
3A14EB
3A10EB
E680
CA0320
3A04EB
C30020
GO
WAIT
LDA EB14
LDA EBlfO
ANI 80H
JZ WAIT
LDA EB04
JMPGO
CLEAR SECTOR FLAG
READ A-STATUS
WAIT FOR SECTOR FLAG
SET WRITE REO
with the scope positive edge-triggered on the signal SECTOR
FLAG (6A pin 8) the following signals should be observed.
SECTOR FLAG
6A pin 8
WINDOW
9F pin 6
TRANS
9F pin 9
HUNT
9E pin 6
WRITE REQ
9G pin 6
WRITE
9E pin 10
WRITE DATAl
8B pin 6
High for 30-40us then low
High for 96us then low
One 8us positive pulse after 96us
Low for 480us then high
Low for 6S-7Sus then high
Low for 104us then high
High for l04us then 8 negative pulses at
8us intervals then random negative pulses
at 4 or 8us intervals
North Star MICRO-DISK System
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