I have four Tandem T16/6530 terminals. Before I recycle them, is anyone
interested in one or more? I will want a minimal amount to cover
time/packing.
Contact me off-list if you're interested. You have until May 20 before
they get turned into iPods.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
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Dave writes:
> and IBM's current large-scale
> storage technology which is also called RAMAC, which stands for Raid
> Architecture with Multilevel Adaptive Cache.
Wow, that's a backronym I never would've dreamt up!
I once contracted at a place where in the memos they actually
wrote Dazdee and Raymack. And instead of ASCII they wrote ASC2 !
If I used any of the terms correctly they made me edit them
to the approved way... it was a pretty bizarre inbred culture there!
Tim.
Date: Mon, 12 May 2008 22:13:59 +0100 (BST)
From: Tony Duell
> Actually, I htink there's a smaller one. DIdn't at least one of the
> Soviet handheld computers (Elektronika MK85 or some such) have a
> PDP11-compatible CPU chip inside?
Yeah, I missed his classifying the handhelds under "calculators"
(he's got a great collection of calculators also). The wallet-sized
MK-87 uses the same PDP-11 clone chip.
BTW, the owner of the site has a great little project he worked out--
a terminal consisting of nothing more than an ATMega16 uC and RS232
level translators to produce a composite video signal (PAL) driving a
32x29 character display. Very clever:
http://rk86.com/frolov/vi_frs.htm
Includes source code and schematic.
Text is in Russian, but is quite readable translated by Google
language tools.
Cheers,
Chuck
> Date: Mon, 12 May 2008 22:11:52 -0400
> From: Dave McGuire
> Evan wrote:
> > Dave, are you not familiar with RAMAC?
>
> Yes I am, both the first RAMAC circa 1956 which stood for Random
> Access Method of Accounting and Control, and IBM's current large-scale
> storage technology which is also called RAMAC, which stands for Raid
> Architecture with Multilevel Adaptive Cache.
This reminds me of the Monty Python Cole Porter-"Anything Goes" skit.
:)
Cheers,
Chuck
> Message: 22
> Date: Mon, 12 May 2008 11:57:16 -0500
> From: "Jason T" <silent700 at gmail.com>
> Subject: Re: Another classic comp job
> To: "General Discussion: On-Topic and Off-Topic Posts"
> On Mon, May 12, 2008 at 10:31 AM, Evan Koblentz <evan at snarc.net>
> wrote:
>> Dave, are you not familiar with RAMAC?
>
>
> Could they really still have a running RAMAC?
>
Why not? Early computers were built to last, some still are but
competitive pressure means 'commodity' machines seem to be lucky to
last more than twice their (UK) legal one year warranty period.
My (1962) 1301 can even still read the magnetic tapes which were last
written in the 1970s and the drums still had the bootstrap program on
the write protected bands (of similar age) once we had got the timing
logic adjusted back to specification.
When designing something as revolutionary as RAMAC, they would over
engineer and only in later designs start paring things down. A few
revolutionary designs do of course have weak points and they either
don't make it past prototype stage or the market soon finds the
weakness and stops buying them.
Hey,
I have such a drive. During the upcoming weekend, I'll have
a look for the parts, you're interested in.
Kind regards,
Pierre
>
> On May 11, 2008, at 11:30 AM, Tony Duell wrote:
>
> > I don;'t have this drive, but I am conserned as to why it failed.
> > Presumably it carried too much current, but why?
>
> Tony;
>
> It's part of a voltage filter circuit, yes. It failed as a result of a
> short in a capacitor elsewhere in the circuit. I know what the
> capacitor's characteristics were, so it can be replaced. I do not know
> what the inductor's characteristics were; I need to find out before it
> can be replaced.
>
> ok
> bear
>
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>Vincent Slyngstad wrote:
>Sourcing them is hard. Maybe a pull from some other board that's been
>designated "parts"? I looked at some boards I have (where some idiot
>shaved off all the metal from the edge connectors) but no 8235's there.
Same here - I already checked my collection of UNIBUS and OMNIBUS boards
(at least the ones I was willing to scrap) and no 8235s. I think there's a
couple on the M8330 PDP-8/E TG board, but I'm not willing to kill one of
those :-)
>Are you looking to repair a TD8E, specifically? Those look like simple
B/!A
>switches, activated by SDRD and SDRC instructions.
Yep, I've got a real TD8E to fix that has two bad 8235s on it. Both chips
have one output that's stuck low and right now I can't even plug the TD8E
into the machine - it hangs the OMNIBUS when you do. The board looks nice
and clean, though, so I'm hoping that's all that's wrong.
I did a little research and the 74xx TTL family has many AND-OR-INVERT
type gates (e.g. 7451, 74S64, etc) but even ignoring pinouts and output
drive capability, none of them are equivalent to the DEC8235. The DEC part
has active low inputs (it's really an "INVERT-AND-OR-INVERT" gate) that
nobody else seems to have, so replacing 'em with off the shelf parts would
take at least another chip.
Does anybody know if the DEC8235 is the same as the National DM8235? I
don't have a source for the DM8235 either, but at least that sounds easier
to find. The chips on my board look like they have National logos on them,
but they're house marked with the DEC part number. They're also stamped
"7419", but that's almost certainly a date code - a real 7419 is an inverter
of some kind.
Thanks,
Bob
>
>Subject: Re: Minimal CP-M SBC design
> From: Dave McGuire <mcguire at neurotica.com>
> Date: Sun, 11 May 2008 08:23:13 -0400
> To: General Discussion: On-Topic Posts Only <cctech at classiccmp.org>
>
>Chuck Guzis wrote:
>>> I dunno Chuck...the only reason more CP/M systems weren't ROM-
>>> resident back in the day was due to convention, not technical
>>> restrictions. I (personally) don't think there's anything
>>> non-"period" about ROM-ing CP/M.
>>
>> It's not the ROM-ing of CP/M that disturbs me, but rather the
>> "disklessness" of the thing. Wasn't the whole idea of CP/M
>> originally to give you something to manage files on your floppy
>> drives? I mean, that's what the bulk of the code in CP/M is for--
>> heaven knows, the support for other I/O is nothing to write home
>> about.
>>
>> If one wants to enjoy a "vintage" experience, what sense is there in
>> being diskless? At any rate, even something as simple as a WD1770-
>> type controller added to the design would give that capability with a
>> minimum of support "glue".
>>
>> Alternatively, one could stay diskless and add a sound-effects module
>> to emulate the "chunk" and "grrr" of a head-load and seek--and the
>> "thunk-click" of a drive door being opened and a floppy inserted.
>
> Well I wasn't talking about a diskless system...only one in which
>CP/M itself was in ROM.
When I mentioned it I wasn't running CP/M from rom which by the way
takes recoding of the CCP, BDOS and BIOS to make all the data areas
external. What I was refering to is simply booting it from a rom rather
than off the system tracks. The result of that is then ANY formatted disk
is a boot media and makes the system a bit more bullet proof as a
common fault (STILL) is trying to boot a nonsystem disk or worse having
a power glitch kill the system tracks.
When done that way CP/M is still in ram, can be overlayed, and even
patched. Boot from rom also solves the chicken/egg paradox as the
the system disk does not have to have data/programs.
>> I still don't have the hang of this "vintage" thing yet, probably
>> because I'm vintage myself. Please forgive my density...
>
> I often suffer from the same problem. I think very few of us, even
>here, actually used stuff like CP/M and PDP-11s when they were
>considered current technology.
Speak for yourself. I wish that were true. The first version of CP/M
I ran was 1.3 When it was available and 1.4 was much better and useful.
I had access to PDP-8 ion 1969 and PDP10 in 1971 and got my first PDP11
in 1980(still have it too!). PDP11 stopped being current in the 1990s
when DEC sold the tech and licenses. Up till then you could buy it new
and faster (and then from mentec for years after that).
Allison
>
> -Dave
>
>--
>Dave McGuire
>Port Charlotte, FL
