WOW - a lot of response in just 1/2 day!
Just a few notes to clear up a few things:
I am NOT "giving away" the collection - I will no doubt give away some
parts of it, but I know local (to me) collectors who will take those bits, so
please only ask for freebies if you are very close to Ottawa, Ontario.
It also doesn't do much good to ask me "how much do you want for xxx"
as I really don't know, as I have never made a point of placing values on
the items in the collection - better to let me know what it is worth to you.
Ultimately any particular item will go to whomever places the highest
offer, or in some cases places where I know the particular bit of equipment
will do the most good or have beneficial effect.
At present I am planning to keep at least one of the Altairs, the Imsai, the
Vector, the Horizon, the H8. one of the "chicklet" Pet 2001s the VLC VAX,
the D6809 (or course) and a probably couple of others I have not decided on ***.
*** I'll willing to entertain offers on these systems, but don't expect them
to be cheap - I'm just as happy to hang on to them.
I'm not keen to ship - I know this lets out many (most) of you, but preference
will definately be given to people who can arrange pickup or take care of
most of the shipping hassles remotely. In particular, I can't easily tell you
what shipping will cost - most of this stuff is heavy, and it is a lot of work to
pack something, measure it, weigh it and get a quote - which will likely be
too high (as you all know, much of this stuff isn't worth the cost to ship).
I'm happy to work with you to figure out ways to get things to you - perhaps
piggybacking transport on someone already planning to come here etc..
(You might be able to coordinate such things through the list as well).
Thanks,
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield
I've long thought that my pdp2011 would run just about anything pdp11.
However, it was recently brought to my attention that RSX-11Mplus will not
boot from an rp06 disk image. I mean, an rp06 image created on simh, based on
the rd54 image in rsx11mpbl87.dsk.bz2, sysgenned to support rp06 drives, and
working without any problem on simh.
The first steps in the boot on the fpga appear to work fine - several reads are
done, and the first message appears: "RSX-11M-PLUS V4.6 BL87 1024.KW
System:"RSXMPL". So far exactly the same as when I run simh on the same image.
However, after a brief pause in which the cpu is busy, a difference appears:
simh will continue with a few reads and finish the boot process; however, my
fpga will start reading sectors from each cylinder of the disk in ascending
order - ie, beginning at cyl 0 and ending at the last one. When at the last
cylinder, the message "SAV -- Cannot find Home Block" appears.
Strangely, if I google that, it comes up with a reference to Ersatz-11 from
1994 which appears to describe exactly the same behaviour - only then on RL,
apparently. See
ftp://minnie.tuhs.org/pub/PDP-11/Sims/Ersatz-1.1beta/Old/e11beta.txt
I've spent most of my free time last week chewing on this problem, looking at
many details in my controller vhdl. However, I've not come any closer to a
solution. At this point, I'm not even completely sure that the problem
actually is in the controller - since E11 had the same thing in it's RL, and
that is a completely different thing.
So, I'm hoping that someone on this list can help me understand what the
trigger(s) for the "SAV -- Cannot find Home Block" could be. Is there maybe
someone who remembers the original issue in E11, and how it was fixed? Or is
there someone with access to the source code who could explain what happens?
The long saga of making my recent KA655 acquisition work
continues! It's been mostly smooth sailing since I got
a decent Plextor drive, but there's one persistent problem.
Under VMS 7.3, after a longish period of inactivity (I've
seen it after a few hours, but I've not been able to
narrow it down beyond that), it seems to just kind of go
out to lunch. VMS is still *running*... if I have a
Telnet session running MONITOR, the clock will still update
and the activity meters still move (a little; they show
very little activity, but that's expected since there's not
a lot going on on the machine yet). But if I terminate
MONITOR (it responds interactively to ctrl-C, etc) and try
to run anything else (say, HELP), it stops responding.
Other terminals are totally unresponsive. If I try to
open a Telnet session, TCP connects but no other traffic
happens.
This also happens if I turn TCP/IP off. I'm running with
16 MB RAM, which should be enough for a machine that's not
really running much yet, and if I were having memory issues
I would expect things like existing MONITOR sessions to
have serious problems.
The only other correlation I can think of is that this
seems to happen most when I've just installed a layered
product, so it could have something to do with the CD
still being mounted. On the other hand, I tend to leave
the machine alone and unattended for long periods of time
for product installs, so correlation is necessarily not
very trustworthy here.
I can still issue a break from the terminal and boot again
>from the console firmware, so that still seems fine.
If anyone has any idea what might be going on here, I'm
all ears.
- Dave
Hey guys.
Here are some DEC drives, among other things. Obviously someone who
selected interesting hardware and stored it rather carefully.
I was considering the Apollo or even the Technostar, but it would be an
effort for me just to get there. If anybody is closer or very
interested, tell me, so I may not bid. The seller (acting on behalf of
owner) wrote he gave the PDPs "in good hands :-)" (his own?), but his
prices are not so low, and he says he is considering 350 EUR for 8
apollos with only one Monitor, two keyboads, mice, unknown condition,
long storage...
Just wanted to point you to the auctions, just in case.
ebay auctions:
251267118551
251270611957
251268195362
251270185222 PDP RL02, some RL06 and 07 have apparently already ended.
etc. pp.
(Please look for other auctions of this seller, included completed ones.)
I think it would definitely be very sad to let these machines go to
scrap - would anybody second that? :-)
Kind regards, Joerg
>> The collection can be seen at: www.classiccmp.org/dunfield
>>
>> [Keep trying if it says "service unavailable" - the classiccmp
>> server seems to be having problems lately]
>>
>Most of the picture links appear broken. :(
The links are not broken.
The classiccmp server is broken. The photos don't work because
you browser cannot access them - try enough times and you will
usually see them (or go nuts trying).
It's not just my site - the entire classiccmp server is having problems
and has been for quite some time.
Most of you don't see it because you access cctalk/tech via email,
which gets done "in good old time", however I am not actively
subscribed to the list any more (too mucn traffic), so I read the list
via the web archives - depending on the time of day and phase of
the moon, this can be damn near impossible. Many days I just give
up.
Makes the site pretty useless I agree - If anyone can provide a better
host for the site I'm very interested, but for now I just don't have another
place to put that much material - the alternative is probably going to
be just taking it down as it really hasn't worked properly in weeks.
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield
I'm trying to install a hard drive IBM H3256-A3 (manual here
<http://www.hgst.com/tech/techlib.nsf/techdocs/7BF937434F9F7BBC86256E9000734
60D/$file/oem3fspe.pdf>
http://www.hgst.com/tech/techlib.nsf...e/oem3fspe.pdf ) in an IBM AT 286.
I state that the motherboard 286 type 1 with a controller AB-862G SUPER
MULTI I/O CARD and a pair of drive performs the correct boot of the dos 4.0
(with no hard disk connected and configured), and that the alone hard drive
works and has been perfectly formatted in dos way on another P3 machine.
I replaced the original U27 and U47 with the bios
BIOS_5170_30APR89_AMI_D286-1277-043089-K0 (downloaded the AMI BIOS FOR 5170
at the bottom of this page <http://www.minuszerodegrees.net/bios/bios.htm>
http://www.minuszerodegrees.net/bios/bios.htm) to have the option 47 user
disk.
Following the instructions given in the manual of the hard disk IBM H3256-A3
fields to be filled in bios are: cyl = 872, heads = 16, Wpcom = 65535, Lzone
= 0, sect / trk = 36, obtaining a total capacity of 245.205 MB
(=872x16x36x512/1048576).
After turning on the machine, however, it stops and it does not proceed
either boot from a floppy or even the keyboard responds any more. Instead
without hard drive connected and / or configured the machine works
perfectly.
Thanks for any useful suggestion.
Enrico
I've put together a small box of old TTL books, computer references
of all sorts that I simply do not want anymore. If someone really wants
to collect old databooks instead of me sending this stuff out to pulp
let me know. It would be easiest if someone local to me here in Ottawa
could deal with it. The other alternative is for me to get it moved
to Toronto for someone else to deal with it.
- Diane
--
- db at FreeBSD.org db at db.nethttp://www.db.net/~db
I acquired an Apple IIe at the dump the other day (and a pair of IIgs
machines, sans keyboards/mice - more on those later, probably).
Something heavy has been dropped on the keyboard - there's no damage to the
keytops (amazingly), but the keyboard PCB is cracked and the frame mounting
points bent, and in testing switches around the damaged area I've found
that the '=' key is permanently shorted (I assume it took the brunt of the
impact from whatever-it-was, unless the switches in these machines are
prone to decay and subsequent shorting).
Anyway, is it just a case of desoldering the switch and prying it out of
the metal frame, or is there more to it than that? I did try a little
careful coaxing and it didn't want to move, but I don't want to try more
force if it's the wrong approach.
cheers
Jules
I'm in the process of trying to resurrect a MicroVAX-II system.
I have a RRD50 cd reader and the associated KRQ50 controller. What I'm
missing is the cable between the cabinet kit and the drive.
I've tried various incantations, including a AUI cable (DA15 to DA15)
and what I think is a straight-through cable. I also hooked the cabinet
kit DA15M direct to the drive with no success.
In most cases the drive spins up but when I try to boot it, the red
error LED on the drive blinks then it spins down.
So, I've got to build a cable. Does anyone have documentation of the
pinout of what I need to build?
Thanks,
-Rick
one of the guys at my hackerspace has a intel mds 225 its power up to diag
mode when the board is pulled from the back plane but when inserted the
screen goes all fuzzed and crazy never been able to trouble shoot it gone
over it with a meter pulled all cables boards out put them back in
has pile of software and manuals and drawings to go with it
and a prom rom programer reader and a another device of some sort
http://www.flickr.com/photos/1ajs/6171038488/lightbox/
funds going to supporting a community hackerspace.
if i was not broke i would just buy it myself to add to pegcity bits
i can get a video of it powering up if anyone wants to see
make offers
o its located in winnipeg canada
They just had an e-waste recycling event in town; different company to the
one that did such an event once before. Last time I was allowed to check
for vintage systems, but there wasn't anything useful there - just
few-years-old PCs.
This time around there was an entire dumpster full of vintage Apple
hardware, but I wasn't allowed anywhere near it - it all goes back to
Wisconsin for "processing". Apparently they do occasionally ebay some
vintage items, but the way this lot had just been tossed into the dumpster
makes me think that it's all off to the crusher. (and of course there was
the Disk II drive that I need, sitting right on the top of the pile!)
Of course it's their right to do what they want with it - it's just
frustrating not being able to save any of it.
Jules
---------- Forwarded message ----------
> From: "Zane H. Healy" <healyzh at aracnet.com>
> To: "General Discussion: On-Topic and Off-Topic Posts" <
> cctalk at classiccmp.org>
> Cc:
> Date: Wed, 1 May 2013 14:48:41 -0700
> Subject: Re: Multicians wonder what terminal this might be
> At 2:37 PM -0700 5/1/13, Jim Stephens wrote:
>
>> imgur is a bit confusing. try this.
>>
>> http://imgur.com/a/6FnnP
>>
>
> Is it sitting on something, or is the base part of it?
>
> If the base isn't part of it, it reminds me of the TEMPEST terminals from
> Honeywell that I used on a DPS-8.
>
> Zane
>
We had hundreds of those VIP screen-mode terminals connected to a Honeywell
DPS-8 in Cambridge. The big blue box had a synchronous RS-232 port to
connect to a multi-drop synchronous modem and eventually to the Datanet
front-end processor. The serial protocol was special for the VIP. There
were two COAX cables from the big blue box to the terminal, one for the
keyboard and one for video. Some of the really old versions had mercury
delay lines for the video memory.
--
Michael Thompson
All;
I'm curious as to what other manufacturers/systems supported the use of
block-oriented magnetic tape media along the lines of the DECtape (TU56)
and DECassette (TU60) drives.
In particular, what about the use of standard 1/2" tape media under such
circumstances? A wear-n-tear problem given the multi-pass nature of this
use (especially if being used to store temp-files for the OS), but if that
scenario were avoided ...
I'd like to play around with some, but acquiring either a DECtape or
DECassette unit looks to be somewhere between impossible and merely
seriously unaffordable -- not to mention obtaining media for use with
either. So I'm thinking about whether there are possibly other drives out
there for which I might construct a suitable controller to mediate between
the raw(er) mechanism and the OS.
Unlike a streaming tape unit I'd expect that a major consideration would be
keeping the moment-of-inertia of the reels as low as possible, consistent
with holding a sufficiently long tape at sufficient bit-density to achieve
an economically-viable amount of storage per tape (*e.g*., 256Kb --
DECtape was 184K 12-bit words or 144K 18-bit words).
DEC managed it; did anyone else?
(Of course, if anyone has a lead on a DEC unit -- DECtape preferred -- I'm
very interested.)
Thanks for your thoughts!
-----
paul
As mentioned in my post about IIe keyswitches, I acquired a couple of IIgs
machines at the same time as the IIe (along with an AppleColor RGB monitor)
- but no ADB keyboards or mice.
I've just checked over both systems; one has an Apple memory expansion
board fitted (2MB, I think) and the other has a Harris GS Sauce memory
expansion board (also 2MB via a pair of 1MB simms) and what I think is an
Apple SCSI board (nifty!).
Both seem to power up OK and sit there trying to boot from non-existent
media (display via composite; I don't know if the CRT monitor works - it's
on the to-do list to make a cable).
Anyway, the machine with the SCSI card looks to be an earlier board, and
has a keyboard socket soldered to the PCB. Wikipedia seems to suggest that
this should accept the keyboard from my IIe, albeit with reduced
functionality over a genuine ADB keyboard - however, is it as simple as
plugging it in, or are there other tweaks that are necessary for it to
work? (e.g. perhaps worst-case a ROM change for a ROM that I don't have!).
Although I'd like to get an ADB keyboard and rodent, I'm curious to see if
the IIe keyboard will work in the meantime...
cheers
Jules
Anybody need actual official data cassettes? I've got two (2) free to
anybody who wants to pay the cost of shipping - I'll use bubblewrap and
toss them in the smallest USPS flat rate box, that's $5.80 last I checked.
"Maxell High Density Data Cassette
- 183 m / 600 ft.
- 16,000 ftpi.
- D/CAS-86 COMPATIBLE
CS-600XD
Made in Japan"
Labels are blank, write-protect switch is in the protected position.
Excellent condition, clean, not sure where I found them. PayPal preferred.
--S.
Long shot, but does anyone have any documentation or software for the Imlac
PDS-4? I'm working on an Imlac emulator/simulator (for the -1 and -1D) and
I'd like to support the -4 as well, as it appears to add some interesting
options; problem is I'm not finding a lot of detailed information about
what and how it works :).
(Hardware documentation/schematics would also be interesting - I have a set
of what appear to be PDS-4 core memory boards and I'd love to be able to
debug them since they're in rough shape...)
- Josh
>>> When you create 360/1.2M disks by formatting on the PC - can you then
>>> read and recreate those disks with IMD?
>> I tried reading and then recreating a DOS 360K disk. Worked fine.
>>
>> It even seemed to read a known good Kaypro disk. But, I tried writing
>> it out with no luck. It did, though, write it out with no errors, so
>> I think I have two issues. One is that the K10FLOAD.TD0 file that I
>> converted to an IMD did not convert correctly, and the other is a lack
>> of correct settings on IMD.
>>
>> When I read my known good DSDD Kaypro boot disk, I set tracks to 80,
>> stepping to double, and sides to 2. But, IMD tries to read all the
>> way up to track 80, when I thought it would stop at 40 (80 tracks,
>> double stepped).
>Update: I was able to copy a known good Universal ROM boot disk and
>boot it on the K1. So, at least I know my setup works. I still don't
>understand why the read of the disk tries and fails to read tracks 41-80
>with doublestepping on. I also don't understand why running td02imd on
>k10fload.td0 didn't create a good imd file I can use with the utility.
If you take the time to read/understand the IMD docs and/or help screens,
you will note that I explicitly state that IMD does not make ANY assumptions
about your drive. It simply uses the capabilities of the controller to see what it
can find "out there". The point of note here is that it supports up to the theoretical
maximum of 255 cylinders that the 765 controller architecturally supports. So
why would it assume that your drive cannot have more than 80 physical cylinders.
It has no idea what type of drive you have.
Sure, drives with more than 80 cylinders aren't common, but sometimes extra
data is hidden in an extra track beyond the end... Some times two tracks ... why
may any such assumptions - At one time 8" drives with 77 cylinders were "as big
as it gets" - so NEC designed a 77 step limit into the original 765 ... which means
they fail on long seeks on more modern 80 cylinder drives - requiring software
workarounds ... IMD makes no assumptions about the drive - it simply does what
you ask it to do.
When you set double-stepping, you are simply telling IMD to send two step
pulses for each cylinder it wants to move the head. It will try to read the number
of cylinders that you specify. It does not "guess" that your drive may not be big
enough to contain those cylinders because of other settings that you have made.
IMD is about doing what you ask it to do, not trying to "fix it up for you".
If you want to read a 40-cylinder disk --- set it to read 40 cylinders.
It defaults to 80 cylinders because that will read most comon disk types
without the user having to actually know what he is doing.
Most drives will allow seek a couple of tracks past the certified number
of tracks. In *MOST* disks, these "extra" tracks will not contain any
data.
At it's default settings, IMD will stop when it encounters a track with no
discernable data - in *most* cases, this signifies the end of data tracks
on the disk. So if you read a 40 cylinder disk while set to read 80, it will
read 0-39 and stop on track 40. But this is because it "ran out of tracks"
when it hit the extra track (40 = track# 41).
But... if the disk contains data in this area, IMD will happy continue reading
up until it either runs out of data, or hits the specified cylinder limit. This is
why some of my Kay disks have the extra SD track 40 -- the original disks
actually have this track one step beyond the certified limit of the drive.
It also means that if your drive does not step past the certified limit, or you
have data in all of the "extra" tracks before it hits the stop, then it will
continue to step, banging the head against the stop until it gets to the
number of cylinders you specified (because it never runs out of tracks
with data).
I designed IMD to be a fairly powerful tool, and not to limit you by making
assumptions about what you are doing - as a result, you have to know more
details about what you are doing than "other" disk archival utilities ... I do
provide a lot of useful information in my docs and help files to help you get
it sorted out, but it does require an inventment in time/effort to get there.
Which leads to the question ... if you have TeleDisk images for the disks
you want to create, and are finding IMD unsuitable - why not use Teledisk
to recreate the disks. TeleDisk is designed to "make it easy" - it looks at
the BIOS settings to see what kind of drive it is, and makes decisions
based on that - for basic operations, it will be simpler than IMD to use.
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield
>> When I read my known good DSDD Kaypro boot disk, I set tracks to 80,
>> stepping to double, and sides to 2. But, IMD tries to read all the way
>> up to track 80, when I thought it would stop at 40 (80 tracks, double
>> stepped).
>
>WHOA!
>You asked for 80, and it tried to do 80. You seem to be assuming that it
>would divide by the double-stepping and do 40. (Actually, it is prob'ly
>planning to stop at #79, V #39)
>
>1) When IMD asks "tracks", is it asking
>A. Cylinders of the disk format (AKA "tracks [per side]")
>B. number of cylinders TIMES number of heads
>C. cylinders of the DRIVE
The setting is "Cylinders" in the main settings menu, and it indicates the maximum
number of cylinders that IMD will attempt to read from the disk (when writing IMD
uses the cylinders occuring in the image - unless you use the track exclusion
feature to avoid writing certain ones).
>But, are you sure that IMD is counting both sides of a cylinder as
>separate tracks?
>When dealing with hardware, it is not uncommon [albeit inaccurate] to
>treat "track" and "cylinder" identically.
>"1.2M drives are 80 track" V "360K drives are 80 track (40*2)"
>"Directory is on track 4" usually does NOT mean cylinder#2, side B
IMD uses "Cylinder" to refer to the actual cylinders - ie: actual steps
of the head(s) - it uses the "Singe/Double sided" setting to determine
how many tracks occur in each cylinder ("as read" means it will try to
read both sides for the first few tracks to determine.
>> But, when I set retry to 0, and it goes all the way up there, I still
>> don't have a good copy.
>
>If retry is set to 0, then it won't even try again when it hits an error,
>which is VERY common with floppy drives.
>NOT GOOD for getting usable disks. A good default is 5 - 10
>In SOME programs, NO RETRIES is useful for TESTING, as ANY error, no
>matter how soft will be reported.
>In SOME programs, 1 - x are the normal values, and 0 is treated as a
>special case, either as '0' means "never stop trying until you succeed",
>which is useful for desperate recovery, or
>in SOME programs, '0' is a special case, and just means 256, 65536, or
>4294967296 (DEC CX JNZ...)
In IMD 0 is a special case, but it means to quickly scan the disk getting
what it can on one read and NOT to re-analyze the disk if it cannot read
data from a track - in doing so it also prevents the automatic stop when
data runs out ... it's just a quick way to scan the whole disk to check a
particular format. Agreed is it not recommended as a way to get reliable
disks.
>BTW, Kaypro puts an INCORRECT value in the "Head Number" field of the
>sector headers of all of the sectors on side B. Fortunately, like the
>extraneous SD track that Dave encountered on the 41st cylinder (#40), it
>is ignored in use. Both are irrelevant to the current project, but quite
>important if you want to use INT13h to read, write, or format Kaypro
>diskettes.
They also use different sector numbers on side 1 - in fact, they logically
number both sides as if it were a single side (head 0) with ascending
sector numbers through the sectors on both sides.
IMD simply records the cylinder, head and sector numbers found in the
sector headers of any given physical track and recreates them as it
writes the disk - it does not expect them to contain any particular value,
so it reads/writes kaypro disks with no problems.
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield
I have a broken SGI Indigo I'd like to fix, but I have no idea where to start.
The most obvious problem is that shortly after power on - two seconds, maybe
three - a noise starts coming from the internal speaker. The sound becomes
louder and louder with every second. No startup chime, no output on serial
console.
My initial thought was a broken power supply, but a PSU repair guy I've found
claims that power supply is ok and voltages are correct and clean. He also
says that he tried to bend the "mainboard" - probably the CPU board - slightly
and this sometimes leads to the startup chime.
Any suggestions are welcome. Thanks :-)
--
If you cut off my head, what would I say? Me and my head, or me and my body?
Anyone have a listing of shows coming up in the NY/NJ/CT area...
Anything for computers and/or videogames...
I would like to see about getting a vendor table to sell copies of the
Atari Inc. book and to also sell my USB joysticks and my newer versions
that are ready May 1st.
Thanks.
Curt
>Booted to DOS 5.0, on AT class machine, drive B set to 1.2MB, formats
>and writes/reads disks fine. imd has been copied to HD, as well as IMD
>image.
>>
>> If you are booting to real/raw DOS ... does the drive work under DOS.?
>Yes
>> Can you FORMAT 1.2M and 360k disks under DOS and read/write
>> them.? If not, you have a hardware problem (for DOS, make sure it is
>> configured correctly in BIOS - IMD doesn't use BIOS settings though).
>Works fine
When you create 360/1.2M disks by formatting on the PC - can you then
read and recreate those disks with IMD?
If yes, then likely your hardware setup is working. If no, then you may have
some compatibility issue with the mainboard controller. (IMD does direct
access to the FDC hardware)
Fred's post below also reminded me that Kay disks are 10x512 - this can
be "a bit tight" for some PC controllers. 765's and derivitives have a "blind
spot" just after the index hole - and some versions are worse than others.
Once you try to recreate a Kay disk and it fails ... try reading the first track
back. Does it get most of the sectors. If the first or last sector is missing,
then it likely held off writing the first sector long enough that the whole track
with the "extra" sector didn't fit in the remainder of the track.
If this happens, you could try slowing the drive down slightly ... you may be
able to create a readable disk that way (I almost always have to slow my
drives by a few rpm to write Cromemco disks for example). You might also
make readable disks by reducing the gaps from the precalculated values..
a little experimentation may be in order.
IIRC you indicated that you were using a Teac 1.2M drive - it might be
jumperable for 300rpm ... if so, try that - running the controller at 250kbps
might improve the situation. I find that generally recreating DD disks can
be a little more forgiving with 300rpm drives.
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield
>> >A further tip: when writing new floppies with IMD (to generate original Kaypro bundled
>> >software for example), I found it easiest to Format the floppy under 22DISK first, as it
>> >knows the correct settings for a Kaypro floppy, then use IMD to write to the formatted
>> >floppy. Doing this meant the only setting I had to set on IMD is the Double Step (as I
>> >have a 1.2MB (80 track) drive, not a 360KB (40 track) drive.
>> Makes no sense. IMD knows the exact format of the particular disk that it is writing
>> as this was determined at the time it was read, and is represented in the metadata
>> of the IMD file - it also formats the disk as it writes it, removing any previous formatting.
>> And ... if he's writing on a 1.2M drive (presumed in a HD controller) , he WILL need to
>> set a 250->300kbps translation in addition to double-stepping in order to write the disks.
>Could part of the confusion there be that
>SOME 1.2M drives are 360RPM only, and therefore require the 300kbps
>data transfer rate, and
>SOME 1.2M drive are 360RPM/300RPM, and when in a 300RPM mode can use the
>250Kbps data transfer rate?
Is there a "standard" for setting drive speed? - I don't think I've encountered an actual
dual speed HD drive setup in a PC (except for some of mine which have a manual
"speed switch" on the front panel added by yours truly :-). IMD doesn't know anything
about changing the drive speed as I have not seen documentation on this so if this is
possible on some drives/controllers, then it might explain it - if 22disk had changed the
speed of the drive.
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield