Date : Fri, 02 Jan 1998 12:59:43 +0000 (GMT)
From : Dave Lambley <dfl@...>
Subject: Re: disk controller info
On Tue 30 Dec, Crispin Boylan wrote:
> At 21:15 29/12/97 +0000, you wrote:
> >On Sun 28 Dec, Crispin Boylan wrote:
> >> hii
> >>
> >> Does anyone have info on the 8271 and 1770 disk controllers?
> >> I'm looking
> >> for things such as pin outs, and other general data on the
> >> controllers.
> >If it helps, I have quite a few WD 1770 datasheets. Are there
> >any details you want?
> >
> Its basically the more electronic side of the info that I would
> like, such
> as the pin outs, I have info on programming it, but I need info
> about the pin outs, if you woul be so kind!
>
Actually on looking closer, it looks more like the WD 1771-01 as used
in the Kenda DMFS, but it is almost certainly the same...
_
!x = x
TABs are assumed to be at 8 chars.
Pins
1 Vbb -5V
2 !WE !Write enable A logic low copies the data
on the DAL into the selected
register when CS is low
3 !CS !Chip select
4 !RE !Read enable A logic low on this input
controls the placement of
data from a selected register
on the DAL when !CS is low.
5,6 A0-A1 Register select:
A1 A0 !RE !WE
0 0 Status register Command register
0 1 Track register Track register
1 0 Sector register Sector register
1 1 Data register Data register
7-14 !DAL0- !Data Access Lines Enabled by !RE OR !WE
DAL7
15 !PH1/STEP !Phase 1/Step If the !3PM input is low then
16 !PH2/DIRC !Phase 2/Dir three phase motor control is
17 PH3 !Phase 3 selected and !PH1-PH3 outputs
18 !3PM !3 phase motor select are used to control it.
19 !MR ??? !PH1 is active low after !MR.
20 Vss GND
21 Vc +5V
22 !TEST !Test Should be tied to +5V or
left floating.
23 HLT Head load timing When this is logic 1, the head
is assumed to be engaged.
24 CLK Clock Free running 2MHz +-1%
square wave for internal uses.
25 !XTDS !External data Logic low or open selects
seperation the internal data separator
26 FDCLOCK Floppy disc clock For external data separation
27 FDDATA Floppy disc data Raw data if !XTDS is 1 or
externally separated data if
!XTDS is 0.
28 HLD Head load Controls the loading of the
RW head against the media.
29 TG43 Track greater than 43
30 WG
31 WD Contains clock and data bits
32 READY Ready Same is !b7 in the status
register
33 !WF Write fault
34 !TR00 !Track 00
35 !IP !Index pulse Held for a minimum of 10us
when an index mark is found
on the disc.
36 !WPRT !Write protect A logic low terminates a
command and sets the write
protect bit.
37 !DINT !Disc initialisation If !DINT=0 the operation is
cancelled and the write
protect bit is set.
38 DRQ !Data request Indicates that more data is
needed in the data register,
or the data is waiting to be
taken.
39 INTRQ Interrupt request Set at the completion
(successful or otherwise) of
any operation.
Use a 10k pull resistor to
+5V.
40 Vdd +12V
--
DFL
'Our management consultants have even questioned our need to
have a pantomime horse.'