-------------Original Message:
Date: Sun, 19 Oct 2008 01:29:14 -0400
From: "Roy J. Tellason" <rtellason at verizon.net>
Subject: Re: Req: Help/Advice on Cromemco System
<snip>
The catch, though, is that the System 3 needs a +24V supply as well, for
the FDD. I have one, and it uses an oddball connector, too, which is one
of the reasons I haven't gotten around to fixing the drive yet (which has
problems), I need to make an extension power cable for the drive so it can
be powered up and out in front of the case.
(Snip)
----------------Reply:
Sounds like you've got one of the later System 3's with a Tandon TM848;
the older ones used dual-slot Perscis, which used 110VAC for the motor.
And of course he could also use a 5 1/4" drive instead.
m
----------Original Message:
Message: 28
Date: Fri, 17 Oct 2008 18:01:40 -0700
From: "Chuck Guzis" <cclist at sydex.com>
Subject: Re: Req: Help/Advice on Cromemco System
On 17 Oct 2008 at 12:21, Dave McGuire wrote:
> > Since I have been unable to find any power supplies which provide
> > the +/- 8 and +/- 16 volts, I just thought of an idea the other day
> > of using a PC power supply and shorting out the on-board voltage
> > regulators to allow them to work at the +5V and +12V of the power
> > supply. In order to do that though, I would need a small (3-5
> > slot) motherboard to test a couple of cards together.
>
> I don't think it's going to be possible to short around the +5 and
> +12 regulators in a PC power supply, as they're not discrete in that
> way. Your best bet (IMO) is to surf eBay for an big open-frame
> linear power supply.
Brute-force linear is definitely the way to go.
I'd be tempted to grab a couple of filament transformers, a couple of
bridge rectifiers and some big caps. The great thing about S100
power supplies is that PSU regulation isn't important. A 6.3VAC
filament transformer hooked through a bridge rectifier and a big
electrolytic should be close enough. +/-16 could be furnished by a
small 12.6v transformer.
The real job of regulation is furnished on each board (usually
something like 78xx 79xx linear regulator ICs).
Cheers,
Chuck
--------------
-----------------Reply:
A misunderstanding, I think: he's talking about shorting out the
regulators on the *cards*, not in the PSU, and running regulated
+5 & +/-12 on the bus; should be doable with a heavy enough
bus and sufficient bypassing, in fact I think some manufacturers
did indeed do just that.
I have a Cromemco PSU BTW, but probably not worth shipping.
mike
Hello all,
This is a slightly modified version of the message that I've posted to comp.os.vms. Wanted to see if anyone here might have an idea.
I'm trying to prepare an old AlphaServer 1000a with installed video card for an installation of VMS or Tru64.
The difficulty starts when I turn it on. Sometimes the LCD on the front is active and displays the self tests and beeps once. More often than not, however, it remains blank and there is no beep.
When the LCD _does_ turn on, the blue SRM console appears _temporarily_ some moments later on the monitor. For example, I notice that the tests have been successful and the machine gives me the ">>>" prompt. Then, about 1 min later, the screen goes dark -- even if I'm in the middle of typing something!
Any ideas?
Thanks,
- Alex
I have most of the stuff to put together a System 3. I have the card cage with the 21-slot motherboard and a bunch of cards. The manuals I got with the system include the Cromix manual, I have more than 1 64-K RAM card and at least one TPU, so I believe that mine was a multi-user system. I would like to put this back to near-original, but need a case and power supply.
Since I have been unable to find any power supplies which provide the +/- 8 and +/- 16 volts, I just thought of an idea the other day of using a PC power supply and shorting out the on-board voltage regulators to allow them to work at the +5V and +12V of the power supply. In order to do that though, I would need a small (3-5 slot) motherboard to test a couple of cards together.
If anyone has any of these available, I would be interested in obtaining them. I do not have much money, but do have some other old computer stuff that I can trade: a VAX Station 2000, an old Sun workstation, many, many old PC parts and systems, lots of electronic parts, lots of microcontroller stuff including several Dev Kits.
Also if anyone has done this before please let me know how it went.
Thanks,
Art
Does anyone use the following server for newsgroups?
freetext.usenetserver.com [208.49.83.84]
I am able to ping and get a response, but for the last 2 days, when I try
to download posts from my favourite pdp-11 newsgroups, I get no reply.
Can anyone help?
Sincerely yours,
Jerome Fine
Message: 10
Date: Sat, 11 Oct 2008 15:04:00 -0400
From: "Roy J. Tellason" <rtellason at verizon.net>
Subject: Re: Looking for AT&T 3B1/UNIXPC/PC7300 software
<snip>
>I remember some of those, too, and in fact had some in the files section of
>my bbs. But I also remember stuff that would deal with "foreign" formats,
>in particular there was "Media Master" and "Uniform". The former was simply
>a file transfer program, while the latter would actually "mount" a foreign
>format disk under an otherwise unused drive letter, both of which I had
>occasion to use under CP/M. I'm pretty sure that at least MM was available
>under DOS as well, dunno about Uniform.
I have MS-DOS versions of Media Master and Uniform, if anyone is interested in a copy. As I remember Media Master, it would let you set up a drive as the foreign type, to read/write/format a disk (except you could not format a Kaypro and one other type using MM).
Bob
I have MP-F17W-50L
I've tried to use this on a PC (long time ago), and it wouldn't work.
It came out of Codex equipment...
Unsure if there is just some magic jumpers required, or this was
custom made for Codex.
So, anyone know anything about that model drive ?
-- Curt