-------------Original Message:
Date: Sat, 12 Jan 2008 09:37:06 -0800
From: "Chuck Guzis" <cclist at sydex.com>
Subject: Re: Creating new CP/M disks - Progress on IMSAI
> Date: Fri, 11 Jan 2008 23:50:27 -0500
> From: "Richard A. Cini" <rcini at optonline.net>
> Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb
> high-density; no schematic) drives Im using is that the motor runs all of
> the time (just like an 8 drive) but these late-model Teac drives dont
> have head relays, so the heads are engaged all of the time.
Since the 8272/765 does drive "polling", you have to connect DRIVE
SELECT/ to DRIVE SELECT/. Connecting it to MOTOR ON/ would likely
have some odd effects. Recall also, that the 765 can do overlapped
seeks on multiple drives, which requires that the DRIVE SELECT/ line
be what it says it is.
Which leaves you with connecting HEAD LOAD/ to MOTOR ON/; not a good
solution if you do a lot of multiple-drive operation (as CP/M floppy
systems are wont to do). Better would be to use a timer to monitor
the HEAD LOAD/ line and keep MOTOR ON/ active for a minute or so
after the last drive activity. A (or a couple) of NE555's should do
the trick.
Recall that with the 55GFR, as the drive will not gate INDEX/ pulses
until it's determined that the diskette's come up to speed. (This,
BTW, is why hard-sector diskettes don't work in a 55GFR). So if
you'r getting INDEX/ pulses, the drive, by definition, is ready.
That's not to say that you couldn't get a GFR with a head-load
solenoid, but they're pretty uncommon.
My take anyway.
Cheers,
Chuck
----------------Reply:
That was going to be my last-ditch suggestion for the TEAC, putting a
one-shot delay on the /MOTOR ON line (Chuck, you know how I love 555s ;-).
That delay on the 55GFR is not only a problem with hard-sector diskettes;
when I went through this exercise replacing 8" drives on my Cromemcos
(soft-sector), the GFR didn't work because the /DS -> /READY delay was
too long, even with the motor spinning. Tying /READY to ground made it
work and I suppose one could tie /READY to /DS with a diode if one
had no other drives available.
Interestingly, Andrew Lynch apparently got a different version of the GFR
(-149 IIRC) to work on his Vector with HS disks, whereas my -159 never
goes ready at all with HS disks.
The YE YD-380 does have a HL solenoid but AFAIK it's not separately
controllable; there's a pair of jumpers (HM & HS) that select whether
the head loads on /MOTOR ON or /DS. Nevertheless, it's probably
the closest to an 8" drive with a HL solenoid and constantly running
motor.
One thing I've learned from trying to use 1.2Mb HD drives in anything
other than an AT is that among the dozen or so drives I tested there's
almost no consistency at all as far as jumper options and labelling,
/READY and /INDEX logic, etc. are concerned, even with different
versions of the same make and model.
One of the most adaptable drive in my limited experience has actually
been the Panasonic JU-475 FWIW.
mike
>
>Subject: Re: Creating new CP/M disks - Progress on IMSAI
> From: M H Stein <dm561 at torfree.net>
> Date: Sat, 12 Jan 2008 12:53:13 -0500
> To: "'cctech at classiccmp.org'" <cctech at classiccmp.org>
>
>Date: Sat, 12 Jan 2008 09:23:02 -0500
>From: "Richard A. Cini" <rcini at optonline.net>
>Subject: Re: Creating new CP/M disks - Progress on IMSAI
>
>>> As a matter of fact, the motor did run constantly on many 8" drives (remember
>>> that many had 110V AC motors).
>>>
>>> m
>
>>Yes, but the heads engaged and disengaged to reduce wear. On modern drives,
>>the heads remain engaged but the motor stops.
>
>---------
>Exactly; that's why you're having problems. But A & A seem to think there's
>something wrong with /MOTOR ON being on constantly, which can be quite
>normal on an 8" FDC. Some FDCs do have an option to latch it ON with pin 16
>and turn it OFF with pin 4 BTW.
>
Yes and when two sided drives were introduced the problem then was when the
head were lowered they could "clap" the media can sometimes bite it. Two
sided was a new set of problems.
In the 5.25"world motors were a problem as they were DC brush motors that
would wear both the brushes and the bearings (belt drive). Later drives
like the FD55s have a direct drive DC brushless motor that has none of
those problems.
Anyone ever guess at how long the media lasts with the motor turning and
head loaded in a clean environment? Months.
Allison
>m
>
>
>Subject: Re: Creating new CP/M disks - Progress on IMSAI
> From: M H Stein <dm561 at torfree.net>
> Date: Sat, 12 Jan 2008 12:53:45 -0500
> To: "'cctech at classiccmp.org'" <cctech at classiccmp.org>
>
>-----------Original Message:
>
>Date: Sat, 12 Jan 2008 09:47:58 -0500
>From: "Richard A. Cini" <rcini at optonline.net>
>Subject: Re: Creating new CP/M disks - Progress on IMSAI
>
>It must have been a fluke...I can't get the YE drive to operate reliably
>either. The drive won't recal consistently. I might try lengthening the HL
>time in software and then give it another shot.
FYI if the drive is at track 79... you MUST issue recal twice as the 765
only issues 77 steps MAX to recal. So if you get a recal fail do it again
and see if it works the second time (I bet it will).
Also if the step rate is 3MS set the 765 for 4ms. Some of the floppies
need a 6ms step rate and if stepped faster they will miss a step (or many).
There are three controls in the 765 HLT (wait for head load) for those
drives that load heads and to let the carriage settle, step rate and
head unload time (rarely important). This is set with the Specify
command.
Allison
>I may have to have to stick with the Teac drive and figure out a way to
>control the heads by software.
>
>----------Reply:
>
>If you're talking about a YE Data YD-380 (no suffix; the -B and -C are
>completely different drives), AFAIK it does not have the normal DC/RY
>option. Instead, it has an RY jumper with no pins provided which, when
>jumpered, puts out /READY on pin 4!
>
>mike
>> We have quite a bit of SEL documentation in the Computer History Museum
>> archives.
>
> SEL as Standard Elektrik Lorenz?
System Engineering Laboratories
mini/supermini manufacturer
-----------Original Message:
Date: Sat, 12 Jan 2008 09:47:58 -0500
From: "Richard A. Cini" <rcini at optonline.net>
Subject: Re: Creating new CP/M disks - Progress on IMSAI
It must have been a fluke...I can't get the YE drive to operate reliably
either. The drive won't recal consistently. I might try lengthening the HL
time in software and then give it another shot.
I may have to have to stick with the Teac drive and figure out a way to
control the heads by software.
----------Reply:
If you're talking about a YE Data YD-380 (no suffix; the -B and -C are
completely different drives), AFAIK it does not have the normal DC/RY
option. Instead, it has an RY jumper with no pins provided which, when
jumpered, puts out /READY on pin 4!
mike
Date: Sat, 12 Jan 2008 09:23:02 -0500
From: "Richard A. Cini" <rcini at optonline.net>
Subject: Re: Creating new CP/M disks - Progress on IMSAI
>> As a matter of fact, the motor did run constantly on many 8" drives (remember
>> that many had 110V AC motors).
>>
>> m
>Yes, but the heads engaged and disengaged to reduce wear. On modern drives,
>the heads remain engaged but the motor stops.
---------
Exactly; that's why you're having problems. But A & A seem to think there's
something wrong with /MOTOR ON being on constantly, which can be quite
normal on an 8" FDC. Some FDCs do have an option to latch it ON with pin 16
and turn it OFF with pin 4 BTW.
m
> Date: Fri, 11 Jan 2008 23:50:27 -0500
> From: "Richard A. Cini" <rcini at optonline.net>
> Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb
> high-density; no schematic) drives Im using is that the motor runs all of
> the time (just like an 8 drive) but these late-model Teac drives dont
> have head relays, so the heads are engaged all of the time.
Since the 8272/765 does drive "polling", you have to connect DRIVE
SELECT/ to DRIVE SELECT/. Connecting it to MOTOR ON/ would likely
have some odd effects. Recall also, that the 765 can do overlapped
seeks on multiple drives, which requires that the DRIVE SELECT/ line
be what it says it is.
Which leaves you with connecting HEAD LOAD/ to MOTOR ON/; not a good
solution if you do a lot of multiple-drive operation (as CP/M floppy
systems are wont to do). Better would be to use a timer to monitor
the HEAD LOAD/ line and keep MOTOR ON/ active for a minute or so
after the last drive activity. A (or a couple) of NE555's should do
the trick.
Recall that with the 55GFR, as the drive will not gate INDEX/ pulses
until it's determined that the diskette's come up to speed. (This,
BTW, is why hard-sector diskettes don't work in a 55GFR). So if
you'r getting INDEX/ pulses, the drive, by definition, is ready.
That's not to say that you couldn't get a GFR with a head-load
solenoid, but they're pretty uncommon.
My take anyway.
Cheers,
Chuck
Cheers,
Chuck
20 or so years worth of stuff needs to be gotten rid of NOW in Pasadena
California. I can't take this one due to time and space issues. Email me
at the below address or my ACM address (my first and last name followed by
acm.org).
Here are the highlights:
* A mostly full set of Byte Magazine.
* First and second year of PC Magazine.
* An Altair with a homebrewed front panel.
* Several PCjr keyboards still in boxes.
* An external 8-inch floppy drive.
--
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?
http://www.sciencedebate2008.com/www/index.php
This is a petition to urge all of the US presidential candidates to have a
debate about scientific policy.
(Just fyi, since cctalk is NO place for political talk.)
>
>Subject: Creating new CP/M disks - Progress on IMSAI
> From: M H Stein <dm561 at torfree.net>
> Date: Sat, 12 Jan 2008 09:14:09 -0500
> To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org>
>
>-----------Original Message:
>Date: Fri, 11 Jan 2008 23:50:27 -0500
>From: "Richard A. Cini" <rcini at optonline.net>
>Subject: Creating new CP/M disks - Progress on IMSAI
>
>All:
>
> I?ve been busy lately rebuilding the floppy system on my IMSAI. I
>scrapped the Frugal Floppy 8? in favor of a CompuPro Disk 1 using 5.25?
>disks to emulate 8?. This has been a long running project, but with the
>assistance from someone on comp.os.cpm who went through the exact same
>process with nearly the same hardware, I?ve been able to create a brand new
>CP/M 2.2 master disk. Yeah!
>
> Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb
>high-density; no schematic) drives I?m using is that the motor runs all of
>the time (just like an 8? drive) but these late-model Teac drives don?t have
>head relays, so the heads are engaged all of the time.
>
> I?m looking for some advice/whatever on engaging the motor when needed.
>The Disk 1 is based on an 8272 controller chip and it has a HDL (head_load)
>signal which, through jumpers can be made to appear on the *MOTOR signal pin
>of the standard IBM floppy disk interface. I tested the HDL signal and it
>activates at the right time, so its following the 8? sequence, but the pulse
>width leads me to believe that it?s too short to let the motor spin-up and
>go ?ready?.
Cannot use that as the HLT parameter is soo short for adaquate spinup time.
You might get away with it though as the FD55GFRs do spinup fast.
The Disk1 Didn't have a direct motor control port like the 1A but it did
allow for using the latch used for serial output to be used as a general
motor on. Find MotorENA on the schematic.
> There is a way to control this with software...and I may go that route
>anyway...but has anyone done this sort of thing < used a 5.25? HD drive to
>simulate an 8? drive and if so, which drives did you use?
The DISK1 serial port if not used as boot console is a 1 bit port that
can be controlled with software. It's in the manual, switch S1-3. The
manual covers all the things for 5.25" floppies.
To do a read or write you set motor enable, wait 1sec then read or write
and reset motor enable. To minimize starts and stops a timer of 10seconds
or more is desireable.
Its the way I'd do it using the DISK1 and have done it with the DISK1A.
The disk1A has a differnt specific port for that which is part fo the 1 to
1A differences.
Allison
>
> Any input appreciated. Thanks.
>
>
>Rich
>
>---------------Reply:
>There are several different OEM versions of the FD-55GFR with
>various jumper options.
>
>If yours has one, put a jumper on the ML position and isolate the
>/MOTOR ON signal somehow (tape over pin 16).
>
>You will also have to change the DC jumper to RY in order to get
>a proper /READY signal.
>
>Whether it will ultimately actually work will depend on the controller;
>there are more issues with 1.2HD drives than one would expect.
>
>mike
>
Date: Sat, 12 Jan 2008 09:22:38 -0300
From: "Alexandre Souza" <alexandre-listas at e-secure.com.br>
Subject: Re: Creating new CP/M disks - Progress on IMSAI
>> I?m looking for some advice/whatever on engaging the motor when needed.
> How is DS0 line activated? As far as I know the sequence should be:
> - Activate DS0, motor starts to run
> - Activate "head load" so the heads can do their job
> - Read/write
> Since your motor is always on, seems that you have DS0 activated
>permanently. Isn't something wired wrong?
---------
As a matter of fact, the motor did run constantly on many 8" drives (remember
that many had 110V AC motors).
m
>
>Subject: Re: Creating new CP/M disks - Progress on IMSAI
> From: "Alexandre Souza" <alexandre-listas at e-secure.com.br>
> Date: Sat, 12 Jan 2008 09:22:38 -0300
> To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
>
>> I?m looking for some advice/whatever on engaging the motor when needed.
Forst if you running motor only when needed you need a delay in software
for the motor to come up to speed (1 sec does it).
> How is DS0 line activated? As far as I know the sequence should be:
>
> - Activate DS0, motor starts to run
> - Activate "head load" so the heads can do their job
> - Read/write
>
> Since your motor is always on, seems that you have DS0 activated
>permanently. Isn't something wired wrong?
It's possible the connector is upside down. The other is the drive in
use has a jumper for motor always on.
Also DS0 (thats a zero right?) needs to be selected to read or write
to the the zeroth drive.
Allison
-----------Original Message:
Date: Fri, 11 Jan 2008 23:50:27 -0500
From: "Richard A. Cini" <rcini at optonline.net>
Subject: Creating new CP/M disks - Progress on IMSAI
All:
I?ve been busy lately rebuilding the floppy system on my IMSAI. I
scrapped the Frugal Floppy 8? in favor of a CompuPro Disk 1 using 5.25?
disks to emulate 8?. This has been a long running project, but with the
assistance from someone on comp.os.cpm who went through the exact same
process with nearly the same hardware, I?ve been able to create a brand new
CP/M 2.2 master disk. Yeah!
Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb
high-density; no schematic) drives I?m using is that the motor runs all of
the time (just like an 8? drive) but these late-model Teac drives don?t have
head relays, so the heads are engaged all of the time.
I?m looking for some advice/whatever on engaging the motor when needed.
The Disk 1 is based on an 8272 controller chip and it has a HDL (head_load)
signal which, through jumpers can be made to appear on the *MOTOR signal pin
of the standard IBM floppy disk interface. I tested the HDL signal and it
activates at the right time, so its following the 8? sequence, but the pulse
width leads me to believe that it?s too short to let the motor spin-up and
go ?ready?.
There is a way to control this with software...and I may go that route
anyway...but has anyone done this sort of thing < used a 5.25? HD drive to
simulate an 8? drive and if so, which drives did you use?
Any input appreciated. Thanks.
Rich
---------------Reply:
There are several different OEM versions of the FD-55GFR with
various jumper options.
If yours has one, put a jumper on the ML position and isolate the
/MOTOR ON signal somehow (tape over pin 16).
You will also have to change the DC jumper to RY in order to get
a proper /READY signal.
Whether it will ultimately actually work will depend on the controller;
there are more issues with 1.2HD drives than one would expect.
mike
Hello!
In an attempt to resurrect an old Mitsubishi MR535R (RLL) drive, I managed to
pick up an ST11M controller by accident - it was advertised on eBay as "MFM or
RLL".
Two things:
1) Does anyone have a spare set of control and data cables? I'm willing to
pay for 'em, or visit Maplin for components to make up a set, since they're
probably easy to make with IDC connectors and ribbon cable.
2) Does anyone happen to have a suitable RLL controller they're looking to
get rid of, or could let me have access to one for a few hours? The 60Mb drive
possibly contains some very old RM Net 3.1 software which I'd like to archive
off, as there doesn't seem to be anyone at all - even at RM - who has any
software left. I'd be happy to travel (within reason, I'm in London, UK) and
exchange use of a controller card for beer/alcohol :)
Cheers
Peter
--
Peter Hicks | e: my.name at poggs.co.uk | g: 0xE7C839F4 | w: www.poggs.com
A: Because it destroys the flow of the conversation
Q: Why is top-posting bad?
Hi,
I recently received a Commodore A2024 monitor. This is a 15" monochrome/
grey-scale monitor which has a special converter board inside, that
converts the 15kHz video output by an Amiga computer to 31kHz. It also
supports a "tiled" mode, whereby Amiga video frames are combined to
produce a 1024x800 or 1024x1024 pixel image.
Unfortunately the monitor was damaged in transit and the tube is
cracked. However the converter board should be usable. I want to make an
adaptor to connect the converter board to a standard VGA/multi-sync
monitor.
Has anyone on the list connected an old workstation (or maybe an Atari
ST?) with monochrome output to a modern monitor? Those should be
similar.
There should be no problem with the horizontal and vertical scan rates.
I need to look at the board circuitry, but I'm pretty sure the
horizontal and vertical sync signals will be at TTL levels, which is
fine for connection to a VGA monitor.
The monochrome video signal is output on a phono/RCA socket. Inside the
monitor, a coaxial cable goes from that to the PCB at the end of the
tube.
I need to determine the video signal level. Apparently VGA uses 0.7V
p-p, so I might need to add a resistor in-line to reduce the voltage if
it's any higher. Unfortunately I don't have access to an oscilloscope.
Could I just arrange for a full-screen white image to be shown, measure
the voltage using a normal DC multimeter, and multiply up the value
shown to account for the proportion of each scanline corresponding to
sync/flyback?
Once that issue is solved, I should be able to connect the video signal
to the green signal pin of a VGA monitor and get a green picture. In
order to get a grey-scale picture, can I simply connect the video signal
via resistors to each of the R, G and B pins on the monitor connector?
If so, what resistor values would be needed? If not, I guess I could use
or build a 1-to-3 splitter/amplifier circuit, then connect the 3 outputs
of that to the R, G and B lines.
-- M
I'm hoping somebody might have some old issues of Datamation from the
late 60's.
Somewhere around '68 there was an Ad by Fairchild semiconductor showing
a SEL minicomputer.
Hopefully I could get the original, or perhaps a scanned copy.
I'm trying to locate this for some old friends, we all worked there,
they were there from the very beginning.
I/we would be grateful for any help.
thanks,
=Dan
On Jan 11, 2008 10:00 PM, Zane H. Healy <healyzh at aracnet.com> wrote:
> same reasons the author gave, ergonomics. But then in the 80's this
> kind of thing was normal and none of us gave it a second thought.
Yeah, maybe that's the problem I had with it. And I have to give him
credit for mentioning the holy Model M as one of the best :)
OK, there are a couple that belong there and were expected, but a few
missing, and some that make no sense at all. The C64?? Sure, I still
hit Shift-2 on occasion for a quote, but I learned my mighty speed
typing skills on that 'board.
I think maybe the author(s) were raised on the Microsoft Ergonomic
keyboard, which IMHO should have been on the list:
http://www.pcworld.com/article/id,139100-page,1-c,keyboards/article.html
What model, and where in LA?
Gary
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org]
> On Behalf Of Mo
> Sent: Friday, January 11, 2008 1:47 PM
> To: Gary
> Subject: Free Pet / CBM and Disk Drive in Los Angeles
>
> No, not a 2001.
>
> Pickup only. No shipping.
>
> Inquire within.
>
>
>
>
>
________________________________________________________________________
__
> __________
> Looking for last minute shopping deals?
> Find them fast with Yahoo! Search.
> http://tools.search.yahoo.com/newsearch/category.php?category=shopping
>
>
>
> Message: 7
> Date: Thu, 3 Jan 2008 23:58:20 -0500
> From: "Andrew Lynch" <lynchaj at yahoo.com>
> Subject: inexpensive prototype boards with 22/44 pin edge connector
> To: <cctalk at classiccmp.org>
> Message-ID: <000e01c84e8e$6d61aee0$a903a8c0 at andrewdesktop>
> Content-Type: text/plain; charset="us-ascii"
>
> Hi,
>
> Does anyone know where to get some inexpensive prototype boards with the
> 22/44 pin edge connectors?
>
> I am looking for something like DATAK or VELLEMAN boards preferably under
> $10 a piece.
>
> I have looked but have not been able to find any. Any hints would be much
> appreciated.
Well, these boards are a bit over USD 10 each, but if you're after a
versatile prototyping board that was edge connectors for the VIC 20, the
C64, the C16/C116/Plus-4 and the Apple II line of computers, you might
want to check out the '8 Bit Baby' at:
http://www.protovision-online.de/catalog/product_info.php?products_id=97
You might find them a bit on the pricey side, but given the scarcity of
these type of boards and the fact that you can use them to interface to
several different types of computers, I reckon they're pretty good value
for money.
If you want to re-use them across projects, you can even solder strips
of IC-style sockets to the 8 Bit Baby and build your circuits on
daughter-boards instead.
Hope this helps,
Pete
No, not a 2001.
Pickup only. No shipping.
Inquire within.
____________________________________________________________________________________
Looking for last minute shopping deals?
Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping
Hi All,
I have an Atari SM124 mono monitor with the crazy 13pin DIN plug.
My investigations via google suggest it will take composite video on
pin 2 - anyone know if that's right, and if so, could I use it with
this Superboard II I've just been asked to revive? I'm assuming here
the TV modulator on the Superboard takes a composite input, slap me if
I'm wrong.
Does anyone have a source for the female 13pin connectors, outside of
gutting an ST?
Cheers,
Pete
--
Pete Edwards
"Prediction is very difficult, especially if it's about the future" - Niels Bohr
> On Jan 5, 2008, at 12:39 PM, Roy J. Tellason wrote:
>
>
>> On Saturday 05 January 2008 03:50, David Griffith wrote:
>>
>> And while we're on the subject of Imsai, does anybody have part
>> numbers handy
>> for those switches? I have several that are broken to replace.
>>
>
> They are made by C & K. The 2-position ones are P/N 7101 and the
> momentary are P/N 7105. You can order them from www.IMSAI.net for
> between $11.00 and 12.00 a piece.
Wandering through my inventory I came across a couple of dozen P/N
7101 SPDT (shown: <http://elipsoid.home.comcast.net/~elipsoid/
IMG_5567.JPG>). It appears that these switches have the attachment
for paddles, but are missing said ingredient. However, there are
lebenty-leben varieties of these switches (see: <http://
www.ittcannon.com/media/pdf/catalogs/Leaf/7000toggle.pdf>).
Are these the switches used in the IMSAI and if so how many per unit?
CRC
Hi all,
does anyone have any print sets, schematics, maintenance manuals, operation
manuals, or anything for the Comdyna GP-6? I just got one but need the docs
for it.
If you would be so kind as to CC me in your reply; I'm no longer a regular
subscriber to cctech...
Thanks!
Cheers,
-RK
--
Robert Krten, PARSE Software Devices, http://www.parse.com/resume.html
Wanted: DEC minis, see their good home at http://www.pdp12.org