At 05:48 PM 1/10/2012, Terry Stewart wrote:
>I've recently had some discussions with someone who collects a particular
>brand of classic computer from the early 1980s. He has a few of these but
>they are never, ever switched on or tested. He doesn't want to test them
>as he feels doing so may damage the old electronics.
Aldo Leopold said "The first prerequisite of intelligent tinkering is
to save all the pieces."
- John
A few days ago I announced that this year's VCF East 8.0 Day 1 keynote is Tom Kurtz, the co-inventor of BASIC. Now I'm happy to announce that the Day 2 keynote is Dan Kottke. Dan was a college buddy of Steve Jobs. They went to India together and sought enlightenment. Dan assembled Apple 1 boards in Jobs' parent's garage, and was officially employee #12, although in reality he was in the first five or so. He speaks on Sunday, May 6, at 12:30. Details to be posted at http://www.vintage.org/2012/east and http://www.facebook.com/vcfeast8.
Pontus writes:
>On Tue, Jan 10, 2012 at 04:14:25PM +0000, Mark Benson wrote:
>> Begin forwarded message:
>>
>> > Hi folks - I thought this was interesting and at least *somewhat* OT...
>> >
>> > http://hackaday.com/2012/01/10/help-chris-boot-his-cray-1-supercomputer/
>>
>> Dunno if anyone saw this - looks VERY interesting - can anyone help this guy??
> Doesn't the Cray-1 run of an Eclipse front end. So he is really asking
> how to boot an Eclipse?
Other brand front ends were used too... Cray themselves used an Eclipse, but some
customers used DEC or (ack!) IBM front ends.
If someone wants to understand booting RDOS on a Nova or Eclipse, this is the best start:
http://bitsavers.org/pdf/dg/software/rdos/093-000188-02_Load_and_Generate_R…
----- Original Message:
Date: Tue, 10 Jan 2012 14:50:29 -0000
From: "James Attfield" <james at attfield.co.uk>
To: <cctech at classiccmp.org>
Subject: RE: Cromemco FDC
> Date: Mon, 09 Jan 2012 14:53:19 -0500
> From: "Bill Sudbrink" <wh.sudbrink at verizon.net>
> Subject: RE: Cromemco FDC
>
> I have always found it interesting how quickly people will go chopping
> up circuit boards. Before you do this, consider chopping up a ribbon
> cable instead. Ribbon cables are cheap and easy to replace if you
> later change to a different make of drive or if you simply screw up
> making the modification. I run SA-851's on my 16FDC with a simply
> modified ribbon cable.
Bill, the Tandon 848's look like they have a pretty similar interface to the
SA-851. I have two TM-848-2's I would like to hook up - what chance do you
think that your modified cable might work (I'm with you on this one rather
than board cut'n'shut) and if so could you kindly email me the layout
off-list?
Jim
------------------------------- Reply:----------------------------
I'd be interested as well!
Quinnteam used to make and sell something called a Top Hat which consisted
of a pair of TM-848's mounted side-by-side horizontally across the top of a
Z-2; this was before the 64FDC came out so they made a number of mods to the
*drives * in order to work correctly with the 16FDC.
I've still got TM-848s out of scrapped Top Hats and they work well with the
16FDC, as well as unmodified TM-848s out of scrapped System 3's which work
with the 64FDC, but I've never taken the time to investigate just what's
involved in getting either drive type to work with the other FDC; this
thread has kind of reawakened my curiosity.
Maybe some folks on the Cromemco mail list have more information...
mike
At 3:54 am +0000 2012/01/09, Evan Koblentz wrote:
>Perhaps quite a lot, but not $800,000. :)
>
>Ebay #190404561375
I still think Intel should issue a commemorative 4004 in 22nm. Or failing
that, easter-egg one (or a few thousand) into Haswell somewhere.
--
Kevin Schoedel <schoedel at kw.igs.net> VA3TCS
----- Original Message:
Date: Mon, 09 Jan 2012 22:29:10 -0800
From: Josh Dersch <derschjo at mail.msu.edu>
To: General Discussion: On-Topic and Off-Topic Posts
...
> I've created a few floppies from my PC on a 5.25" drive using ImageDisk, I
> have been unable to get the FDC to read them (or boot, obviously). I
> wasn't 100% sure it wasn't just the setup I have on my PC getting in the
> way, hence my latest attempt to use the FDC itself to write the disks.
You don't say which images and whether you're talking about a DD drive or an
HD drive emulating an 8" disk.
Let me say it again: very few PCs will reliably write the Cromemco 360K DD
format, but 8" images written to a 1.2M HD drive (on 1.2MB disks!) are
usually quite reliable. See below.
>> You are aware that using a 5.25HD drive as an 8" requires a jumper to
>> connect /READY to the FDC's 5.25" interface?
> I was not aware, but the 16/64FDC has connectors for both 5.25" and 8"
> drives, I've been using the 5.25" connector and the controller seems to be
> able to communicate with it OK -- it has no trouble seeking and formatting
> tracks... it just can't read or write them at the moment...
Umm... if you can't read it how do you know it was formatted correctly?
The 5.25" connector normally only supports DD drives/formats (which, as I
said, are notoriously unreliable reading disks made on a PC) because the
/READY signal needed for 8" drives is not available on that connector. To
use the more reliable 1.2M HD drives (360RPM with 1.2M HD disks) (or
3.5" HD drives for that matter) connected to the 5.25" port as 8" you need
to connect pin 34 to /READY (and jumper the drive to supply /RY instead of
/DC). Incidentally, that also avoids the 8" drive issues that Bill and
Amardeep are arguing about.
So, frankly, I'm very skeptical that your 1.2M HD drive is working at all
*as an 8" drive*. BTW, your 300RPM HD drive is also going to be troublesome
if not completely useless.
And of course you have to select the correct drive type in RDOS with one,
two or three semicolons.
I'd be surprised if the 1793 were the problem, especially both of them. The
4FDC had a bad reputation for that, but out of the 20+ Cromemco systems that
I supported (and still have most of) only ONE ever developed problems
reading disks and I never did investigate what the cause actually was.
No offence, but most likely you're doing something wrong; image/disk
incompatibility, wrong type selected, etc. etc.
Good luck!
> Date: Mon, 09 Jan 2012 14:53:19 -0500
> From: "Bill Sudbrink" <wh.sudbrink at verizon.net>
> Subject: RE: Cromemco FDC
>
> I have always found it interesting how quickly people will go chopping
> up circuit boards. Before you do this, consider chopping up a ribbon
> cable instead. Ribbon cables are cheap and easy to replace if you
> later change to a different make of drive or if you simply screw up
> making the modification. I run SA-851's on my 16FDC with a simply
> modified ribbon cable.
Bill, the Tandon 848's look like they have a pretty similar interface to the
SA-851. I have two TM-848-2's I would like to hook up - what chance do you
think that your modified cable might work (I'm with you on this one rather
than board cut'n'shut) and if so could you kindly email me the layout
off-list?
Jim
On Mon, 9 Jan 2012, Bill Sudbrink wrote:
> Bill Sudbrink wrote:
>>
>> I have always found it interesting how quickly people will go chopping
>> up circuit boards. Before you do this, consider chopping up a ribbon
>> cable instead. Ribbon cables are cheap and easy to replace if you
>> later change to a different make of drive or if you simply screw up
>> making the modification. I run SA-851's on my 16FDC with a simply
>> modified ribbon cable.
>>
> By the way, based on your description of the symptoms, I still suspect
> the 1793 is going bad.
Unicorn Electronics may have stock on the 1793 -
http://198.170.117.30/IC/CRT.html it's listed for $4.99.
g.
--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.diy-cockpits.org/coll - Go Collimated or Go Home.
Some people collect things for a hobby. Geeks collect hobbies.
ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://www.scarletdme.org - Get it _today_!
Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a turd
by the clean end.
----- Original Message:
Date: Mon, 09 Jan 2012 08:13:10 -0800
From: Josh Dersch <derschjo at mail.msu.edu>
...
Right now I have both a 16FDC and a 64FDC to play with (one is on
loan). I'm using Dave Dunfield's RDOS transfer utilities to upload the
"INIT" software into RAM from a PC.
...
I'm wondering if there's some fundamental problem with my current set-up
that's causing issues here...
- Josh
----- Reply:
Have you tried creating a bootable Cromemco format disk (CDOS or CP/M) from
an image? Even if it's a configuration that doesn't match yours, you could
at least run some diagnostics on the diskette using RDOS.
The 5.25DD format can be troublesome to create, but generally an 8" image on
a 5.25" HD disk & drive is no problem, especially if you can use the same
physical drive in the PC and the Cromemco and avoid any alignment issues.
You are aware that using a 5.25HD drive as an 8" requires a jumper to
connect /READY to the FDC's 5.25" interface?
mike