8-bit IDE

From: Richard Erlacher <edick_at_idcomm.com>
Date: Tue Apr 18 01:14:42 2000

There's no real difficulty involved in making the interface work. The one
thing I get out of doing this sort of thing myself is that I get to decide
how it SHOULD be done and the do it that way if possible. It's not
difficult with today's technology to build a simple IDE interface that
handles the bytes and words correctly.

However, it seems to me that, if there is supposed to be a means built into
the "standard" interface by means of which I can avoid having to deal with
the conversion to/from words on the data port, I should exploit that
feature. Finding the drives that support that feature is then the crux, but
it should be achievable. In no case will it be of any significant economic
value.

Unfortunately, there seems to be precious little information around about
whether this feature is available, and if so, on which drive models.

Dick

----- Original Message -----
From: Jim Strickland <jim_at_calico.litterbox.com>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, April 17, 2000 11:58 PM
Subject: Re: 8-bit IDE


> I know someone has made an ide hard card for the 8 bit apple 2 bus that
takes
> modern IDE drives, including the 1 inch notebook drives. I'm unclear how
it
> was done, but you can buy one at www.allelec.com/harddiap.htm .
>
>
> >
> > Well, I've got one drive, an ST351, I think it is, that responds to the
> > 8-bit conditioning. It's a 1.25"-tall 3-1/2" drive, of 44 MB capacity.
> > That's not what I want for the "hard-card" on the S-100.
> >
> > All your assertions about the relative folly of expending
effort/resources
> > to make the drive talk-8-bits wide has no real purpose except to bind it
to
> > its historical roots. I'd bet that the logic in the 1003-WAH uses the
> > data-width bit to enable the IOCS16- signal and thereby lets the AT bus
> > control whether the transfer is 8 or 16 bits wide, since the AT bus is
> > required to do that.
> >
> > The early IDE drives made for COMPAQ by Seagate, were half-high 5-1/4"
> > drives from which I've saved one or two of the PCB's. These have all
the
> > same logic on them that I recognize from the 1003-WA2 which is a WAH
with
> > the FDC missing, I think. Maybe it's the other way around . . .
> >
> > Those guys undoubtedly supported the 8-bit mode, since their host was,
in
> > some cases, an XT-class machine.
> >
> > Dick
> >
> > ----- Original Message -----
> > From: allisonp <allisonp_at_world.std.com>
> > To: <classiccmp_at_classiccmp.org>
> > Sent: Monday, April 17, 2000 8:22 PM
> > Subject: Re: 8-bit IDE
> >
> >
> > > > "Has anyone got sufficient experience with the IDE in
> > non-PC-compatible
> > > >applications to say, unequivocally, whether the 8-bit operating mode
> > > >described in section 6 of the standard for the ATA (IDE) interface,
yes
> > > >SPELLED OUT, actually exists in drives of the pre-1996 vintage?" It
was
> > > >dropped from the standard in 1996. There seem to be many folks with
> > > >suggestions about how to implement this extremely elementary
interface.
> > > >There seem to be few who know whether the standard was every full
> > > >implemented.
> > >
> > >
> > > Why would they include that? NONE of the PC hardware they were
intended
> > > for wants to run as 8bit bus. Even the crippled SL/SLC run as 16bit
> > busses.
> > >
> > > >Allison seems to be the only one who's tried this, and, I fear, it
may be
> > > in
> > > >a PC-compatible, where all bets are off as to what really happens.
> > >
> > >
> > > Obviously visually impaired! I don't hack IO in PCs nor have I tried
that
> > > yet.
> > > I may add why even bother, IDE works there as is.
> > >
> > > ALL of the IDE work I've done was with 8085, z80s either stand alone
> > > (bus less) or S100 Z80s. Further I'm currently working on a Z280
system
> > > with IDE (Zbus 16bit). This is where I need interfaces and so I can
> > replace
> > > older MFM or non-existent hard disks. I currently have one S100
system
> > > running a connor3044A (40mb) IDE that will be upgraded to a ST3250
> > > (250mb) as it's a better drive.
> > >
> > > The drives I've tried include:
> > >
> > > Connor 2022
> > > Connor 3044
> > > WD2120
> > > WD2420
> > > St3096A
> > > St3144A
> > > St3250A
> > > St3660
> > > Fijitsu 528mb
> > > Quantum LPS 80 and 120
> > > Maxtor 124mb
> > > and afew other sub 60mb WD, NEC, Seagate drives.
> > >
> > > I now have two 2.5mb IDE in the 700-800mb region I may try one day.
> > >
> > > I do have two WD PS/2m30 compatable 8bit IDE 20meg drives.
> > >
> > > I think this is a good cross section
> > >
> > > Allison
> > > >
> > > >Dick
> > > >
> > > >----- Original Message -----
> > > >From: Mike Ford <mikeford_at_socal.rr.com>
> > > >To: <classiccmp_at_classiccmp.org>
> > > >Sent: Monday, April 17, 2000 7:22 PM
> > > >Subject: Re: 8-bit IDE
> > > >
> > > >
> > > >> I don't know a hoot about this, but I wonder if taking a look at
the
> > > >> Sequential Systems Focus card for the Apple II might be instuctive.
Its
> > a
> > > >> controller and notebook IDE drive that all fits on a Apple II slot
> > card.
> > > >>
> > > >>
> > > >
> > >
> >
>
>
> --
> Jim Strickland
> jim_at_DIESPAMMERSCUMcalico.litterbox.com
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Received on Tue Apr 18 2000 - 01:14:42 BST