I have a 1977 SWPTC floppy disk system that uses the FD1771 controller. It
came with Shugart SA400 drives and I upgraded to TM100. The stock controller
card was single sided and it worked OK, You could use an existing latch on
the SWTPC card to do side select.
You can also use current production 3.5 inch drives with it.
http://www.swtpc.com/mholley/35disk/Disk.htm
Michael Holley
www.swtpc.com/mholley
> From: "Richard A. Cini"
> Subject: Building new S100 floppy system
>
> I have several random parts I'm going to pull together to build
> a "new" floppy system for my IMSAI. I have an SD Sales Versafloppy
> controller card (which used the FD1771B controller) and several 5.25"
> floppy
> drives (all soft sectored). The Versafloppy manual indicates that it will
> work with a Shugart SA400/450. When I look up the specs on the SA400, it
> indicates that the unformatted capacity is 109.6k and the formatted
> capacity
> is 81k. I didn't read the entire manual but this look like SSSD specs.
>
> I of course don't have any floppy drives like this but I have
> several original PC drives (TM-100 and others) and several 360k drives of
> various types.
Someone just forwareded two scans of M9312 boot prom listings. The second
one K-SP-M9312-0-7_Aug78.pdf fills in a couple of missing ones, if someone
feels like entering the data and forwarding it to Jay to add to his prom
archive.
The listings are under dec/unibus on bitsavers.
I've been slowly acquiring operating system media as I find it,
trying to archive it where possible. Unfortunately, I've only just
gotten around to trying to make backup images of my OS/2 2.1
installation diskettes.
One of them is bad, and I can't get a good image from it. If anyone
has this disk, and would be willing to send me an image (I've been
using dd on FreeBSD to make byte-by-byte dumps), I would be very
grateful!
The disk I need is:
IBM OS/2 2.1
Display Driver Diskette 2
61G0808
Version 2.1 (c) International Business Machines
Yes, I do own the original box and disks. I just want to replace a
disk that has failed.
Thanks everyone,
-Seth
They
take up roughly 30 sqft of floor space (each unit is no more than 3x3 feet
>from what I can tell).
--
Nice to see someone is getting the Litton ABS
Where did you hear about it?
Not a "rescue" per se -- it's already been rescued by Sellam - he just needs
help with it.
-----Original Message-----
From: Evan Koblentz [mailto:evan at snarc.net]
Sent: Saturday, May 20, 2006 5:48 PM
To: 'General Discussion: On-Topic and Off-Topic Posts'
Subject: Rescue opp near Jacksonville, FL
Sellam asked me to forward this message to cctalk. Reply to him, not me, at
sellam at vintagetech.com.
- Evan
---------------------------------
Subject: Need help with large mini-computer near Jacksonville, FL
I've acquired a largish mini-computer near Jacksonville, Florida, and need
help moving it. I plan to ship it to California via freight, and am hoping
to make the trip out to Florida so I can pack it myself, but in the meantime
I may have to get it moved from its current location to somewhere nearby.
Is anyone near Jacksonville that can help me with this? A pickup truck and
a couple sets of strong hands is all that's required to move them. They
take up roughly 30 sqft of floor space (each unit is no more than 3x3 feet
>from what I can tell).
I may even just go ahead and rent a small storage locker until I can get out
there to prep the machines for shipping.
Any help will be appreciated and rewarded with some goodies. Please reply
to me directly <sellam at vintagetech.com>.
Thanks!
Sellam asked me to forward this message to cctalk. Reply to him, not me, at
sellam at vintagetech.com.
- Evan
---------------------------------
Subject: Need help with large mini-computer near Jacksonville, FL
I've acquired a largish mini-computer near Jacksonville, Florida, and need
help moving it. I plan to ship it to California via freight, and am hoping
to make the trip out to Florida so I can pack it myself, but in the meantime
I may have to get it moved from its current location to somewhere nearby.
Is anyone near Jacksonville that can help me with this? A pickup truck and
a couple sets of strong hands is all that's required to move them. They
take up roughly 30 sqft of floor space (each unit is no more than 3x3 feet
>from what I can tell).
I may even just go ahead and rent a small storage locker until I can get out
there to prep the machines for shipping.
Any help will be appreciated and rewarded with some goodies. Please reply
to me directly <sellam at vintagetech.com>.
Thanks!
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org]On Behalf Of Chuck Guzis
> Sent: Friday, May 19, 2006 8:14 PM
> To: cctalk at classiccmp.org
> Subject: Re: ST-412 interface specification
>
>
> Your biggest problem is going to be providing the serial raw data stream
> support. That is, taking fully-decoded data and providing a high-speed
> serialized MFM signal for reading and doing the reverse for writing. It's
> usually a lot simpler if you can ditch the old MFM controller and tie in a
> modern IDE drive directly.
Here is the situation. I have many older systems that only support the ST-412 standard drives. Most use a WD-1005HDO style controller to talk to the machine's bus. I also have several that use a custom controller to interface the system bus directly to ST-412 (without the WD-1005HDO). I'd like to continue using these systems, but I'm quickly running out of working drives.
I do have the specifications for the system bus, but most of the software interface is not documented. I would need to dissasemble the executables to figure out what is going on.
What I interpret what you said above to mean is that the interface between the controller card and the ST-412 drive is not simply a digital interface. It is acutally the MFM stream bi-directionally, and that the controller is what converts this to the system required digital stream, and the systems digital stream to the MFM stream.
Is this essentially correct?
I did find the OEM manual for the 412 on the bitsavers archive. I'll start reading it over tonight.
Kelly
"Kelly Leavitt" wrote:
>
>What I interpret what you said above to mean is that the interface between the
> controller card and the ST-412 drive is not simply a digital interface. It is
> acutally the MFM stream bi-directionally, and that the controller is what con
>verts this to the system required digital stream, and the systems digital stre
>am to the MFM stream.
>
>Is this essentially correct?
This sounds right to me. It would not be hard to make something in
hardware to pull the clock and data back out. You'd then have (as I
recall) the raw bytes for each sector (i.e. header + data + trailer).
If you knew how the controller was programmed you could then easily find
the data. It should also be reasonble to create the stream in the
opposite direction. Some simple tests should prove it out.
I have not done the math but it seems like a PIC or one of the low end
ARM chips should be able to do this... worst case add a small CPLD to
aid in the serial in/out.
In other words, a ST-506 emulator. I'm pretty sure they exist as
commercial products. (but for some reason I never see them ebay or other
on-line auctions)
ps: I found this for any Apple Lisa Profie users
http://john.ccac.rwth-aachen.de:8000/patrick/idefile.htm
-brad
