On Nov 11, 2007, at 11:21 PM, cctalk-request at classiccmp.org wrote:
> I would love to be proven wrong on this, since it would potentially
> make
> my II disk archiving a lot easier, but I have never heard of such a
> device
> for the Mac.
>
> In the case of the IIe card, this was accomplished by connecting a
> regular
> Apple II 5.25" drive to the *card*, not the computer.
AFAIK same for the DOS compatible drive (though a different card, not
the //e).
I think somebody (must not have been Apple) did make some sort of drive
that did the necessary interface juggling to do 5.25" //-series on the
Mac. I was a bit too young to remember specifics, though. Perhaps AE.
Pretty sure I've seen reference to it somewhere.
>
Dave McGuire writes:
> On Nov 10, 2007, at 1:19 PM, Scott Quinn wrote:
> > Couple of questions on old Sun machines (well, parts).
> >
> > On a Sun 4300 CPU board, I'm getting the
> > "EEPROM Write-Write-Read-Read test
> > error PA=0xF2000000 VA=0X00FF8000 Exp=0x0000005a Obs=0x00000000
> > (looping)"
> > error. Looking on the Web and Usenet seems to show that this has
> > happened a couple of times, with some reference to possibly being
> > the NVRAM (although the most comprehensive posing set was in
> > German :(). This seems a bit odd, though - on my other Suns it
> > calls the NVRAM the NVRAM, so I'm wondering if this is something
> else.
>
> It's just a terminological difference. Most of those machines (if
> I recall correctly) used 2816 NVRAM chips, which are also correctly
> referred to as EEPROMs.
Oh, so the Mostek unit isn't what this is talking about. Hmm- have to
go over the board again.
I saw the Mostek and assumed that it was the same as the 4c/m/u NVRAM
setup .
replying to ard at p850ug1.demon.co.uk (Tony Duell)
Subject: Re: Video clips (was Re: modern serial terminal)
Message-ID: <m1IrKbM-000J3RC at p850ug1>
> I am not a 'normal' computer collector, if such a thing even exists.
> For one thing I am primarily interested in the hardware design
> (if I can get a machine running properly so that it boots the normal OS,
> or runs the ROM software, or..., then I tend to lose interest in it).
> I am interested in the electronics/engineering aspects,
> the fact that the devices happen to be programmable computers is secondary to this.
I think I'm in that camp too.
I adored pulling apart old electronics to see the immense
worksmanchip and craftsmanship required just for the assembly.
Old military stuff was designed for reliability, maintenance,
repairability, upgrade/replacement, etc.
Even just verifying in-spec operation ment test points,
built-in meters, test lamps, status indicators, etc.
Things that are TOALLY MISSING from today's equipment.
Will I ever build anything that magnificent by myself?
Unlikely, but I can still aim high.
[a quick rant: I've been having problems with my cable internet.
I knew it was the modem by watching the status leds as it kept rebooting.
How's anyone to diagnose things with only a power LED?
Yea, it's sure great to buy 500+ gig hard drives for $100
but without a REAL activity LED,
how am I to assure what drive is active?
Some drives used to even blink diagnostics on their LED.
New PCs are sure fast but without activity LEDs,
how is one to isolate faults?
That's a far cry from the mainframes
with diagnostic LEDs on each card or part for fault isolation
Yea, remote diagnostics and SMART give more details
but after all that, someone still has to touch the hardware!]
> This has several implications. The first, which I think is on-topic,
> is that I am equally interested in peripherals as CPUs.
> I want to run my PDP11 with RK05s and RK07s and RL02s, and...
> Not an IDE drive pretending to be the above.
> The design of the servo system in an RK07
> is every bit as interesting to me as the processor.
I both agree and disagree.
Yes, it's amazing seeing things in motion
(particulalry linear motors) and motion control systems
where you can SEE the feedback sensors and signals
(not just a black-blob of a DSP doing all the work).
BUT - when those drives were in common use,
there was a support infrastructure.
You could buy new disks and the cleaning kits
and hire people to clean and check the disks and drives
for "preventive maintenance".
The drudgery of doing all that maintenance myself
made me give up many such projects of running old equipment :-(
-- Jeff Jonas
>
>Subject: Re: Tarbell is making me insane
> From: Grant Stockly <grant at stockly.com>
> Date: Sun, 11 Nov 2007 13:21:32 -0900
> To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
>
>Tarbell Update
>
>> >> > Also sounds like oneshot problems. Check cpu timing. Even small timing
>> >> > errors tend to magnify bus noise issues and incompability problems.
>> >>(Snip)
>> >> > Also HEAT. That thing despite a very heafty noisy fan and cover mods
>> >> > didn't like heat. FYI: the timing of the oneshots drifts with heating!
>
>I can't speak for the exact combination of the Tarbell, but the
>system has been running all day long with:
>-16k static card
>-8k static card
>-4k static card
Ok you have 28k ram. Is the image sized and booting in that?
If the image is sized for say 32 or 48K it will crash, likely
as a bounce back to rom monitor.
>-2SIO
Is the boot image set up for MITS 2SIO and does it set it up?
>-1k ROM
>-8k Byte saver
I assume thse are in high memory and not below the address the image will
try to boot to. CP/M wants from 0000h to system size as configured.
When working on FDCs I load the system with a single known good RAM16,
Ram17 or similar 64k static card that can kill the last 4 or 8k. I use
a CPU with resident monitor and local ram (compupro CPU Z) and an
CPro Interfacer for IO. At that point I know I have a known IO,
known CPU and a monitor at F000h with POJ to F000h and ram at F800h.
Any time there is doubt about these they get a quick retest in a
known backplane (NS*Horizon). This means the system will be 4
boards max with the 4th being the FDC in question. I keep a CCS
terminator card handy as it seemed to work the best of all of them.
Things I've found in old backplanes.
Staples under the S100 connectors.
Metal under the backplane shorting to chassis.
Terminators with burned off tracks.
Metal bits in the connectors
Bits of nonconductor in the connectors.
Green cruft in the connectors (corrosion)
Black card edge connectors (gold over copper
without nickle flash, a bad thing)
Power supplies with excessive ripple. (tired caps)
Power traces fried on the backplane (altair 4slots)
Signal traces missing... from a former short?
That doesn't even touch on cards that just didn't play
well in some machines or with certain other cards.
Heres an example of a machine.
I have two explorer 8085s. One I built back when
and another aquired. They are identical as best as
I can see or test. Mine runs perfect, always did
with any card I've tried. the second is flaky,
won't run any S100 card without a bus terminator
and even then it's fussy. I've gone as far as to
completely swap every chip (they are fully socketed)
between the one that is cranky and my old one is
still happy and the newer one not. I've even swapped
PSs ( uses s100 style unregulated) and no dice. All
on board (there are a few) regulators replaced on the
bad one. No help. After a LONG time of testing and
all the problem was a high resistance trace on the
faulty board. I can see the signal at the source IC
solder side but between there and it's terminus it's
a 1000ohm resistor! One of the S100 status signals
was not quite there and floating. I bridged the
trace with blue wire between the two solder pads
and it's solid now. I cannot even with a 10x scope
see where the apparent crack is. That's chasing a
phantom.
But I do find the oddest of the odd.
>-Tarbell FD
>
>It has been running solid a 4K ROM monitor from Dave
>Dunfield. Floppy interface still doesn't work on either card, and
>these cards were tested by someone else on an IMSAI with an Altair CPU card.
If it's the monitor I think, it doesnt stress ram just sitting there.
You need a memory exerciser running at a minimum to be sure.
>>Some Z80 cards complicate the issue. They have different timing and at 4mhz
>>some ram MAY NOT be fast enough. Either slow the z80 to 2mhz or more wait
>>states from ram.
>
>The card I have has a switch for 2MHz. The tarbell with the reduced
>clock speed will not work at anything higher like you suggested. I
>have confirmed (from the person who shipped me the tarbell cards)
>that the tarbell card with a reduced clock speed works normally with
>a Z80 at 2MHz.
Doesnt assure the FDC is set right for the drive and media.
Also doesnt assure the media is SD or even bootable.
Further is the media is not using a 2sio as the IO the system could
boot and crash or appear to.
>
>I attached a logic analyzer to the drive and watched all of the
>signals. Every thing looks normal to me. I hooked it to a 5.25"
>drive and then to a 3.5" drive. The drives are sending everything
>that they should.
Then the FDC is potentialy not decoding the data.
>
>>Shows how rough the bus timing and noise can be. Is that a one piece
>>backplane of the two sided variety or the one of the earlier Altair
>>4 slot chains or single sided backplane? The reason is the earlier
>
>2x4 slot motherboards, but all of the wires are the same length
>(there was a tip on that to reduce noise)
ICKPOO. Those were the worst for ringing and bus power sag. Poke a
scope at it, it's nasty.
>I'm going to let the thing heat soak and then check the bus with an
>oscilloscope and the CPU clock.
if the oneshots are good ones once set they should say put. Then again
there was lore and fact about what was and wasn't good.
>You know, I'm worried that the reliability issues aren't related to
>the Altair, but to a heavily modified tarbell card trying to write a
>Tandon SSSD 5.25" onto a 3.5" disk???
Likely if the data rates are not set right for the FDC and it's data
seperator (usually also oneshots) is not set right it will fail.
Could even be a simple bad IDC crimp on the cable.
>
>Would any of you like to see the data coming out of the disk
>drive? I can upload the logic analyzer data to my web site...
Not I. If I did at the very least I'd also need to see the schematic and
jumper info for the tarbel. Other wise it's just a pretty picture.
>I will never be happy until I find the problem. I'd like to think
>that with all of the information we have that I can make the Altair
>as reliable as any other S-100 system. I have collected a lot of
>errata and have applied it all to my system... That's why I won't
>give up with this setup. : )
Most of the erata is lore not hard tried fixes. Most fall in the
"it worked for me" realm.
The problem is you have a lot of still possibles lurking.
Oh, SA400 drives... had a problem with them and all that used
that frame (sa400, 400l and 450). Seems if the spindle bearings
go bad the amount of jitter on the data can exceed that of simple
data seperators used with 1771 (especially RS early TRS80 with
early EI). I'm sure it's possible to have the same problem with
other drives. Showed up best with the SA alignment disk and
a dual trace scope set up for data read EYE pattern.
Allison
>Thanks,
>Grant
-------------Original Message:
Date: Sun, 11 Nov 2007 19:32:38 -0500
From: "Richard A. Cini" <rcini at optonline.net>
Subject: Re: S100 Floppy Controller Question
Yes, I understand the 5-for-8 substitution. One of the challenges I'm having
is finding a suitable disk image to try. If I get an 8" image I plan on
jamming it onto a 5.25" HD disk and giving that a whirl.
I made the "8"-only" distinction because one of the boards I have (the
Versafloppy) has both connectors. It just saves a little time in not having
to make a cable.
------------Reply:
This is quite possibly not relevant to _your_ controller, but FWIW my
Cromemcos have both the DD and the HD drives on the same cable,
and the 50 pin connector is only used for the 'real' 8" drive.
Although some of the signals have separate drivers/receivers, the
5 1/4 and 8" drives are effectively on the same bus; the only difference
is that the 8" drives supply (and the FDC expects) a /READY signal on
pin 22 (?) whereas the TM-100s did not supply that signal and the FDC
does not look for it on the 5 1/4" cable; I suspect that's how the system
distinguishes between the drives in order to select the correct speed.
Modern HD drives _do_ supply a /READY signal on pin 34, although you'll
probably have to change a jumper since PCs use it for Disk Change; the
jumpers are in fact often labelled DC and RDY.
Therefore all that is required is a jumper on the FDC from pin 34 of the 5"
connector to pin 22 of the 8" (and of course any DD 5 1/4 drives must
have their /READY signal disabled if it's active).
The only other FDC I have any experience with is a Micropolis, and it
_does_ use the /READY signal from its DD drives (although it looks for
it on pin 6, which is normally DS3 or 4), so this wouldn't work.
m
Hi Henk,
I'm in the Netherlands and I would like to have the unit as well.
We are still using it in a sort of test environment and we have a defect power supply in one of them.
We are willing to pay the shipping and additional costs.
Regards Rinaldo
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Henk Gooijen
Sent: zondag 11 november 2007 13:02
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: VXT2000+
Hi ?ngel,
I checked the TPG website. Pity that the unit is just over 5 kilos,
that would have saved 5 euro. Shipping inside Europe will be 24 euros.
I have to find a good box to ship it safely ...If you are interested, send me an off-list e-mail.
BTW, I have been in Granada and seen the beautiful Alhambra!
thanks,
Henk
> Date: Sun, 11 Nov 2007 12:47:38 +0100> From: ama at ugr.es> To: cctalk at classiccmp.org> Subject: Re: VXT2000+> > Hi Henk,> > On Sun, Nov 11, 2007 at 11:45:56AM +0100, Henk Gooijen wrote:> > I am about to throw out a complete VXT2000+> > Shipping overseas is probably not worth it> > (I am in The Neterlands), but if somebody> > needs a specific part, I am willing to disassemble> > the VXT before it becomes landfill. The VXT is> > in good shape AFAIK, but can not test it ... > > I might be interested on the terminal if shipping price permits :-)> > How much could it be to ship to Granada, Spain?> > Thanks and greetings,> ?ngel> > -- > Angel Martin Alganza Tel +34 958 248 926> Departamento de Genetica Fax +34 958 244 073> Universidad de Granada mailto:ama at ugr.es> C/ Fuentenueva s/n http://www.ugr.es/~ama/> E-18071 Granada, Spain JabberID alganza at jabber.org> PGP Public key: http://www.ugr.es/~ama/ama-pgp-key> 3EB2 967A 9404 6585 7086 8811 2CEC 2F81 9341 E591> ------------------------------------------------------> () ASCII Ribbon Campaign - http://www.asciiribbon.org/> /\ Against all HTML e-mail and proprietary attachments> Please avoid sending me Word or PowerPoint attachments> http://linux.sgms-centre.com/advocacy/no-ms-office.php
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> Does MUSIC 4B still exist?
Barry Vercoe at the Media Lab might know. I don't think CHM has a copy.
From memory, MIT's MUSIC 11 has roots in the Bell program.
> if someone has service
> manuals for the C it would be nice if scans could eventually find their way to bitsavers.
I have a lot of material for the C as well as B from a large collection I obtained a few
years ago. The only thing I don't appear to have are the schematics for the 2116A.
All this needs to get sorted out to be included with material available through the HP/CHM
agreement.
