>From: "Hans Franke" <Hans.Franke at siemens.com>
---snip---
> First thing would be
>to connect a logic analyzer to see if the CPU is still running
>a programm in ROM or not.
Hi
What is it with logic analyzers. Why not just an
oscilloscope. In most cases, one can be farther along
with an 'oscope in finding what is wrong by the
time one can get an analyzer connected and setup.
I've only had one time that I ever needed an analyzer
and even that time, it didn't work well because
of the complexity of the problem ( design not failure ).
I'll admit that I've often thought of making one
of those address compare circuits to trigger the 'scope
but by the time I'd get serious, I'd found the problem.
Am I alone here or does everyone else think that an
analyzer is the ultimate tool?
Dwight
>>More and more machines are showing up without physical support (ie:
>>a select) for drive B: ... I have two Intel P3 board which do not
>>drive the B: select (which is very annoying since these are two of
>>the best systems for handling oddball formats with Imagedisk).
>>
>>Floppy drives are disappearing completely from some new machines,
>>and I doubt it will be long before the controller disappears along
>>with them (if it hasn't started already).
>>
>>
>>
>That I suspect will still be built into the support chips since it will
>be too much trouble
>to remove it. Floppies are now a extra option -- I had to have new
>computer built with one.
>Everybody is going to R/W DVD's now..
First the drives/cables go, then the connectors (why pay for a connector
on the board that "nobody wants") - eventually the FDC itself may go
when new chipsets appear (next round of CPU).
Me: I hanging on to my stash of P1/P2 full ISA machines...!
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
>Well some comments. I used to have a lot of them, most all ahve died.
>I regard that particular drive as junk.
Agreed completely.
>The size problem.. I've encountered it with NS* Horizon and Advantage.
>However I put FD55BVs in the NS* after moving the rectifier as I
>prefer them for reliability.
>
>I found a few PC 360k drives (48tpi) marked Newtronics D503 which are
>Mitsumi drives that seem ok and are the shorter length (7-3/8").
>They look like the TEC drives but not quite.
>
>I have toshiba, FD55xx(B, E, F and Gs) and they are the same length.
>Older 286/386 PCs are the source of many of the TEC and mitsumi drives.
In this case the attempt is to keep the machine as original as possible.
I think replacing the drives is not too bad, however to put in a drive
with the data connector in the "wrong" place will require modification
to the interface board in the back of the disk enclosure, which I think
he would prefer not to do.
I've found a few Newtronics/Mitsumi HD drives which will fit (Data
connector is on the back left corner when drive faces you) ... one
option I am considering is to see if I can modify the motor control
board to go to 300 rpm (as far as I can tell there is no jumper) and
strap Pin2 to keep the drive in low-density mode - I can regen and
copy the disks to 80 track... But something more original would be
preferable if I can find it... Do the Newtronics DD drive have the
data connector in the position I described?
Note that it's not so much a size problem, as the fact that there is
a little board directly behind the drive with 1" cables for the data
connectors - you simply can't put in drives with the data connector
on the other side (which is where most of the drives I have put it).
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
>
>Subject: Re: Analyzer was Re: KIM-1 repair advice wanted
> From: "Jay West" <jwest at classiccmp.org>
> Date: Sat, 08 Oct 2005 19:19:54 -0500
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>Someone wrote....
>>> I've been watching Ebay for one for over a year and
>>> there have been NONE
>>> listed. I guess their owner's don't want to part
>>> with them.
>
>Actually, I saw an HP Logic Dart on ebay maybe.... six months ago or so.
>
>Jay West
My use of logic dart was not aimed at the HP device but a lesser
but similar varient. That name came from back when in a shop I ran
many years ago one of the techs like to call the logic probe a
"logic dart". Little did I know then. Tom was bit of a klutz and
could trip sitting down so.. The story behind it was that one time
he asked for "it" and ended up getting darted (stick) in the inner
upper thigh because of a fumble dropping it on his lap. The
descriptive name sorta stuck[sticks]. The one we used around the
shop for minor logic work in scanners and the like was an Eico product
had been modded with a sharp stainless point (aka Dart!).
I still remember the look on his face when it happend. Can you say
a near miss? He almost did.
Now, all the pundits can have fun. Remember _logic dart_.
Allison
I found a pair of these drives and picked them up since my reference said
that they were quad density drives AND they had DS-QD disks in them.
However I looked on the net and found that everyone including Teac's site
says that they are HD (1.2Mb) drives. Which are they? I THINK these have a
jumper that chages the speed from 360 RPM to 300RPM. Will this make the
drive a QD drive? I thought the heads needed to be differnt since the
magnetic media on the disks have different permeability.
Joe
This is a really good controller if you want to run a pertec tape deck
with a formatter.
This puts out the classic 100 pin formatted pertec that can be run by
any pertec controller.
There is a converter from this 100 pin connection to the dual 50's that
became predominate when cipher popularized them.
I have one of the pertec adapters somewhere if someone needs the
pinout if you don't already have the 100 pin cable :-)
Datum Inc. Magnetic Tape Controller 5091
Item number: 5816293974
Jim
Re: "Each track (77 tracks per side * 2 sides) can hold about 8 sectors of
1024 bytes each, or about 15 sectors of 512 bytes, or about 28 sectors of
256 bytes."
It's not a standard format, but it is actually possible to reliably get nine
sectors of 1024 bytes on each track of a double-density 8" disk. I
supported such a format in all of the operating systems that I wrote for the
Zenith Z-100. It gives you 1,419,264 bytes of formatted storage per
diskette.
pulling the thread further off....
One solution for the floppy problem in the dos/winders world is
your run of the mill 486 board with ISA bus. They do not disallow
much as it was easily done to install two floppy/ide/serial/parallel
cards using all of the available port addresses that were nominally assigned.
The result of that is a system with 4 floppies, 4 IDE drives and 4 serial
ports and two parallel ports. The motherboard is later 486/DX66 with 24mb
and ISA16 bus and a large (256k cache). I was lucky to find a large
horizontal case that allowed for a lot of drives and 300W of power. So
the result is a 3.5 (720/1.44 floppy), 5.25 (48tpi teac FD55BV) and
5.25 (96tpi teac fd55gfr) and two 3.5" IDE drives at 512mb, IDE CDrom
each plus N2000 compatable NIC and a 1mb VGA video card. The box is
still not full at this point. With this transfers from any to most is
easy, it runs any OS I'd care to use and have on hand (DOS, W3.1, W95b,
NT4[WS and server], Linux, OS/2warp3, DRI Concurrent dos386V3).
Rather than futz with the latest and greatest hardware and software
for doing stuff that is mostly routine and very nontaxing for a 486
and DOS this was the easiest solution. It's proven handy for more than
a few tasks and having most needed hardware in the box it is a workhorse.
Having at least 500mb per drive is enough for most OSs if not choked with
apps and still plenty of space for storage. CDrom makes install easy and
fast. The extra parallel port is handy with a kangaroo parallel port to
IDE adaptor. The three floppies means nothing common is likely unreadable.
It's also a respectably fast enough to run MYz80 CP/M/z80 emulator. That
is handy for pulling stuff off CP/M disks and munging it or even development.
Allison
