>
>Subject: RE: CompuPro floppy controller differences
> From: "Chuck Guzis" <cclist at sydex.com>
> Date: Sun, 17 Sep 2006 11:32:01 -0700
> To: cctalk at classiccmp.org
>
>On 9/16/2006 at 4:30 PM Allison wrote:
>
>>Ah, it's using the definitive PC FDC. It was developed well before
>>PCs standardized. PCs however don't offer much choice and if they did
>>keep all the FDC features you could put a 8" on a PC and read SSSD!
>
>You could?!? (if I'm parsing your statement correctly). IIRC, the original
>PC FDC card had IBM's proprietary data separator on it (several hybrid
>packagaes) and couldn't read SD/FM to save its life. It also had the 8272
>(non "A") part, so it had other problems with "alien" formats.
Many can. The original IBM PC version was a an abortion. I'd always felt
they worked hard making that mess.
As to the A/nonA part thats less a problem than often thought. If it
really was a problem you could change out the part.
I have a few mid range ISA-8 FDC boards that use the 9216 data sep and
they do read SD 8" and a bunch more.
>Unless, of course, we're talking about PCs in the generic sense and not the
>5150 per se. There, it's a crapshoot as to what capabilites any given FDC
>card has.
In my original statement I was refering to the generic and as "Standard"
its still anything but. When you consider the number of drives and
configurations the floppy whent though on PCs over the years it's a big
mess. It's only that it's all behind us that was know where the bodies
lie and we can assemble it from known history. but it lead to 3.5" drives
with out drive select jumpers/switches and other "innovations".
Over the lifetime of PCs I've worked with:
5.25 180k single sided
5.25 360k 2 sided
5.25 720k 2 sided 80 track
3.5" 720k
3.5" 1.44mb
3.5" 2.88mb
Syquest, Zip, Jazz and other higher density removeables
The only thing they didn't do stock was 8" SSSD and 8"DSDD, and
hard sector! The aftermarket added those!
Standard, really, more like a computer version of a leatherman.. ;)
Allison
For a while, I thought it was a requirement that the laser be turned off at least when the drive was open,
so power-down circutry was required. Not sure if this requirement was relaxed.
So, I'm fooling around with my Tandy PT-210 printing terminal again.
Upon disassembly, these switches are revealed to have rubber domes inside
that electrically connect two isolated semicircles by pressing a circle of
conductive rubber. Wiping with alcohol and blowing them out gives a
closed resistance of around 300 ohms, which is good enough to trigger the
keyboard circuitry. I've come to one that refuses to work at all,
regardless of how I clean it.
So, I have two choices:
1) Glue tiny discs of aluminum to the bottoms of the rubber domes. A
preliminary test of this using water as "glue" suggests this won't work
for long.
2) Find some switches with the same footprint, height, and cross-shaped
acutator. The first two seem easy to get. Mouser lists absolutely no
switches with a cross top.
So, has anyone here any pointers?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
>
>Subject: Re: Bet you didn't know...(PDP-11)
> From: "Zane H. Healy" <healyzh at aracnet.com>
> Date: Tue, 19 Sep 2006 08:30:40 -0700
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>,
> cctech at classiccmp.org
>
>At 7:09 AM -0400 9/19/06, Allison wrote:
>> >
>>>Subject: Bet you didn't know...(PDP-11)
>>> From: Julian Wolfe <fireflyst at earthlink.net>
>>> Date: Tue, 19 Sep 2006 00:07:49 -0500
>>> To: "General Discussion: On-Topic and Off-Topic Posts"
>>><cctalk at classiccmp.org>
>>>
>>>As of September 30, 2006, the last PDP-11 that rolled off the line
>>>will finally be 10 years old.
>>>
>>>The PDP-11 EOL was actually September 30,1996.
>>
>>Mentec continued it and you can still buy new 11 based boards.
>>
>>Allison
>
>Is Mentec still selling them? From the last time I looked at the
>website, it looked like they were only reselling emulators instead of
>real hardware now.
>
>Still up until recently they were selling new boards.
>
> Zane
They may well have stopped cpu production but only recently.The only CPUs
that have been around near as long in production are:
PDP-8 (cmos 6100 and 6120)
1802
Z80
Allison
Found a USIIi/440, went to put it in, my PROM didn't support it, had to have an update using a 300-333 MHz CPU.
So it goes.
Anyway, that's not a problem. I took a second look at the old card and got it working. For some computers that are almost
on topic now, there's a bit of a hidden catch on the CPUs- they aren't firmly attached, and on some of them (I know that
SGI PMT5 modules do not fall into this category, but HP PA-8000s and USIIis do) the connection is effected with a sheet of
something with conductive rubber blips on it (sound familiar? Wonder how these will work in ~20 years). If you are
not careful to go round-and-round the merry-go-round with the device to snug up the heatsink, the processor becomes canted
and does not make good contact, and becomes generally unhappy and huffy and will not work (how's that for a run-on!)
End of story- I now have an OT Sun Ultra 10 440MHz with Solaris 10 on it- Solaris is much happier on SPARCs than PCs.
Western Digital IDE drives from the late '90s to early 2000s seem to be going bad at shocking rates now, also. Beware.
>
>Subject: Bet you didn't know...(PDP-11)
> From: Julian Wolfe <fireflyst at earthlink.net>
> Date: Tue, 19 Sep 2006 00:07:49 -0500
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>As of September 30, 2006, the last PDP-11 that rolled off the line
>will finally be 10 years old.
>
>The PDP-11 EOL was actually September 30,1996.
Mentec continued it and you can still buy new 11 based boards.
Allison
> > > Does anyone know what sort of interface the AT&T 3b2 uses for its mouse?
> > > I found one which is missing its mouse.
> Sorry. I meant the 3b1 (aka Unix PC)
I think it was a logitech two button rectangular wedge shaped mouse
used by lots of vendors. They came in both serial and parallel, I
think the AT&T one was serial. It has been a long time. Both had a D 9
pin connector.
A picture search on google "3b1" brought up a poor picture of the
mouse with one. Hard to see what it actuually is.
I had several 3B1s go through my hands in the early 1990s.
>
>Subject: Re: CompuPro floppy controller differences
> From: "Dave Dunfield" <dave06a at dunfield.com>
> Date: Tue, 19 Sep 2006 05:45:43 -0500
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>> >> You would need quite the desktop case to house an 8" floppy
>> >> drive! :)
>
>> What is more interesting is what a PC with two 8" drives would
>> weigh in at! Most of the good 8" drives were a very solid hunk
>> of aluminum.
>
>There *IS* a (somewhat) PC with dual full-sized 8" drives mounted
>in it - the Nec APC:
>
> http://www.classiccmp.org/dunfield/nec/index.htm
>
>I can tell you that this thing is big and HEAVY - especially the
>color one.
Having used a color one it was a much better machine than the PCxt
(this is back when they were both new).
The Color CRT besides being big was way over my lift limit!
Allison
>
>Subject: CP/M for Fairchild F8 ?
> From: Jos Dreesen / Marian Capel <jos.mar at bluewin.ch>
> Date: Mon, 18 Sep 2006 20:15:05 +0200
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>
>I found a scrapped box today at work :
>
>2 8" floppydrives , RS232 and printer interfaces. Internally an F8
>chipset ( F3850 / F3852 / F3854) with a WD1771 fdc.
>Strangely enough a set of floppies lay on top, labeled Cp/M, Basic CP/m
>Pascal etc.
>
>Was there ever a CP/M version for the F8 ??
>
> Jos Dreesen
No. The F8 at best was a microcontroller. If anything the unit was a smart
floppy controller for a CP/M system.
Allison
