29 Feb
2008
29 Feb
'08
5:13 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Randy Dawson
Sent: Wednesday, February 27, 2008 2:20 PM
To: General Discussion: On-Topic Posts Only
Subject: board scan, design reconstruction (was IMSAI)
> Date: Wed, 27 Feb 2008 09:48:10 -0900
> From: grant at stockly.com
> To: cctech at classiccmp.org
> Subject: Re: TTL CPU Re: IMSAI style C&K 7101 switches
>
> At 06:40 AM 2/26/2008, you wrote:
> >Grant,
> >
> > > On a side note, who here would be interested in ultra high
[snip]
1 Mar
1 Mar
7:39 a.m.
From: lynchaj at sbcglobal.net
Hi,
All those S-100 boards definitely sound interesting but here is a twist for
something I think would be highly useful for recovering data from vintage
computers using generic PCs.
How about a PCI floppy controller board? Maybe with some supplementary
logic to allow raw track reads? Possibly a BIOS to boot from? An external
floppy drive connector?
Just wondering how complicated such a thing would be. Thanks!
Hi
It would be relatively easy if you did most of the work in a DSP chip.
For the floppy end, you need a parallel port to read status and
write controls.
For reading raw data, a 7474 flipflop, an adjustable clock
and a DSP chip, such as a ADSP2118 or similar.
Then you'd need a bus interface to the PCI bus.
Dwight
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2 Mar
2 Mar
8:52 a.m.
On Mar 1, 2008, at 10:39 AM, dwight elvey wrote:
Why not just build that bus interface and put a floppy controller
chip (WD2797, 765, etc) on the other side of it? I suppose the DSP
chip would give you much greater flexibility in terms of being able to
download new code into it to support different formats (even different
types of modulation), but it's much more complex.
Hmm. Now that I think about it, a DSP-based floppy controller would
be amazingly flexible. Wow..
-Dave
--
Dave McGuire
Port Charlotte, FL
How about a
PCI floppy controller board? Maybe with some supplementary
logic to allow raw track reads? Possibly a BIOS to boot from? An
external
floppy drive connector?
Just wondering how complicated such a thing would be. Thanks!
It would be relatively easy if you did most of the work in a DSP chip.
For the floppy end, you need a parallel port to read status and
write controls.
For reading raw data, a 7474 flipflop, an adjustable clock
and a DSP chip, such as a ADSP2118 or similar.
Then you'd need a bus interface to the PCI bus.
3 Mar
3 Mar
7:22 a.m.
From: mcguire at neurotica.com
On Mar 1, 2008, at 10:39 AM, dwight elvey wrote:
Why not just build that bus interface and put a floppy controller
chip (WD2797, 765, etc) on the other side of it? I suppose the DSP
chip would give you much greater flexibility in terms of being able to
download new code into it to support different formats (even different
types of modulation), but it's much more complex.
Hmm. Now that I think about it, a DSP-based floppy controller would
be amazingly flexible. Wow..
Hi
I like the DSP over the PIC because it has several feature that make
it easier to handle this application.
My thinking is that the SPI port makes a great way to sample the
bit stream from the drive. I'd still add a flipflop in front so that one
doesn't have to sample the pulse width, only the spacing between
pulses.
The DSP comes with an efficient barral shifter that would be great
to align data for pattern matching. It is designed to talk to a host
computer with minimal external circuits and contains enough RAM
to buffer the results of a track of data. The circuit would have almost
no external components being that most of the work was software.
The code could even be easily down loaded from the PC to select
differing formats.
With a PIC is it either a bit banging or adding external components
to handle these operations.
Dwight
_________________________________________________________________
Helping your favorite cause is as easy as instant messaging.?You IM, we give.
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How about
a PCI floppy controller board? Maybe with some supplementary
logic to allow raw track reads? Possibly a BIOS to boot from? An
external
floppy drive connector?
Just wondering how complicated such a thing would be. Thanks!
It would be relatively easy if you did most of the work in a DSP chip.
For the floppy end, you need a parallel port to read status and
write controls.
For reading raw data, a 7474 flipflop, an adjustable clock
and a DSP chip, such as a ADSP2118 or similar.
Then you'd need a bus interface to the PCI bus.
6138
days inactive
6140
days old
3 comments
3 participants
participants (3)
-
dkelvey＠hotmail.com -
lynchaj＠sbcglobal.net -
mcguire＠neurotica.com