Spectravideo MKI, Service – Technical Manual

Page: 120 / 134

STATUS
FOR
TYPE I I AND I I I
COMMANDS
B IT
NAME
H EAN ING
S 7
NOT READY · Th i s b i t whe n s e t in d i c a t e s the drive i s no t rea dy . When
re s e t , i t i n d i c a t e s tha t the dr.i ve i s rea dy . Th i s b i t i s an
inve r t e d copy of the Ready input and ' ore d ' w i t h MR . The
Type I I and I I I Corrnnands w i l l no t execu t e un l e s s the dr ive
i s r e a dy .
S 6
WR ITE
On Read Recor d : N o t U se d . O n Read T rack : N o t U sed . On
P ROTECT any W r i t e : I t i n d i ca t e s a Wr i t e P ro t e c t . Th i s b i t i s res e t
wh en upda ted .
s s
R ECORD TYPE/ On Rea d Record
:
I t ind i c a t e s t he record- t ype code f rom data
WRITE FAULT f i e l d addre s s ma rk .
1
=
De l e t e d Da ta Mark
.
0
=
Data Mark .
On any Wr i te : I t indica t e s a Wr i te F
a
u l t . Th i s b i t i s
re s e t whe n upda t e d .
S4
R ECORD NOT Wh en s e t , i t ind icates that the d e s i re d t rack , s e c t o r
,
or
FOUND ( RNF ) s i d e we re not found . Th is b i t is re s e t whe n update d .
S3
CRC ERROR
I f
S4 i s se t , an e r ror i s found in one or more ID f i e lds ;
ot herw i se i t ind icates e r ror in data f i e ld . Th i s b i t i s
re s e t whe n update d .
S 2
LOST DATA
Wh en se t , it ind icates t he computer d i d not respond to DRQ
in one byte t ime . Th is b it is re s e t t o z e ro when update d .
S l DATA REQUES T Th i s b i t is a copy of the DRQ ou tpu t . Whe n se t , i t
indicat e s t he DR i s fu l l on a Read Operat ion o r the
DR
i s
emp t y on a Write ope rat ion . Th is b i t i s re s e t to z e ro when
upda ted .
so
BUSY Wh en s e t , command is unde r ex ecu t ion . When re s e t , no
command is under execu t io n .
4 . 87