>From: ard at p850ug1.demon.co.uk
>
>Certainly the double-density controller in my MDS800 is 3000-based. But
>the microcode is not given in the manual.
>
>-tony
Hi
When I worked for Intel ( years ago ) I knew the fellow
that wrote the micro code for the double density controller.
The sequencer for the 3000 series was not the easiest to
work with. Unlike the 2900 stuff, it didn't just sequence
to the next address ( like most uP ). Each instruction
had an indiction as to what the next address was. The micro
code is organized as rows and columns. One could jump
conditionally or not to another location in a row or
column. There were special jumps to the first row or column.
Filling the micro code ROMs was something like learning
to play a good game of chess. If one wasn't careful, one
would work themselves into a corner that you couldn't get
to the empty space you wanted to use ( other than an
additional clock cycle ).
Dwight
On Dec 31 2005, 0:56, Roger Pugh wrote:
> could this be a ram problem. wasnt the rca 1802 used a lot on
> satellites due to its reliability
It was used because there was a rad-hard silicon-on-sapphire version,
and then some people used the standard versions so they could use the
same code and tools.
--
Pete Peter Turnbull
Network Manager
University of York
Yes, and I seem to remember that an other reason to use the 1802
was because RCA exactly specified what the CPU would do on *any*
"opcode", even for the codes that were not actually instruction codes?
- Henk, PA8PDP.
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Pete Turnbull
> Sent: maandag 2 januari 2006 14:51
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: 1802 problems
>
> On Dec 31 2005, 0:56, Roger Pugh wrote:
> > could this be a ram problem. wasnt the rca 1802 used a lot on
> > satellites due to its reliability
>
> It was used because there was a rad-hard silicon-on-sapphire
> version, and then some people used the standard versions so
> they could use the same code and tools.
>
> --
> Pete Peter Turnbull
> Network Manager
> University of York
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Hi.
Just found this in my spares box. I was going to salvage the display but its not big enough for what I wanted it for.
It seems to work fine, so if anyone wants to add it to their collection make me an offer.
-A
Does anyone have a user manual for a Microwriter MW4 chording keyboard-thing?
If so, is there a procedure given to do a hard reset if the batteries
have gone totally flat and you've recharged them? I have one of these
devices which I am currently running off my bench supply (4.8V) in place
of the NiCd. It seems to power up OK, and you can type exactly 8
characters befroe it locks up.
Before I start testing the processor (1802), RAM (6116s), etc, I wondered
if it was simply not initialised correctly and I needed to do some kind
of hard reset.
-tony
I hear everyone talking about storing their collections and whatnot.
But what about HOW they're stored?
Or, if not collections, how you keep your equipment...
I've been doing housekeeping with my equipment all week, and I've finally
got it sorted thus far -- http://www.tehproxy.com/room/
How's everyone else keep their stuff? Hopefully a little better then I.. :)
> From: M H Stein <dm561 at torfree.net>
>
> A couple of years ago I met a couple of people on here that had
> Burroughs L-series computers, but lost track of them in the meantime.
> (I think there's an L5000 at Bletchley, but they probably don't need
> or want anything).
>
> I'm about to toss out the last remnants of my L stuff (programming
> manuals, memory cards, tape drive, TD-700 display, etc.)
>
> If there's anyone out there still interested, send me an email off-list
> before they go into landfill.
>
What are the Burroughs L-series computers? I started working for
Burroughs just before the Sperry merger and I guess I missed the
L-series.
I collect B1000 stuff (or, I would collect it if I could find anything)
and acquired a bunch of B20 systems a couple of years ago, so I collect
them now.
Other than a museum that asked me if I ever found a B1000, I haven't
found any other collectors of Burroughs stuff.
alan
Chuck Wrote:
>I've got the full set of SCO Xenix System V disks for the Wyse PCs, but
>I've installed it on other systems. The documentation makes references
to
>both the 286 and 386 versions of Xenix, however--and I don't know if
this
>was a "both in one set" package or some other deal. Short of pulling
out
>an 286 AT and trying an installation, is there any way to tell? The
install diskettes were all 96 tpi 5.25", but I've since transferred them
to
>3.5" DS2D. I should probably archive them to CD-ROM.
>Cheers,
>Chuck
Chuck - I'm curious. There was an independent, i.e. not SCO, version of
Unix that Wyse shipped in the late 80's/early 90's for their 7000/9000
systems. It IS labeled as SCO Xenix then?
For that matter - does anyone have any info or actually OWN a Wyse 9000
(an up to 8 processor tower machine with SCSI I/O based on the Sequent
bus.)????
Steve Wilson
Since we are proposing alternatives...
There is a port of Venix (SVR2-ish Unix variant targeted for RT use) for the
8086 and 80286 PC-type machines. I reeeeally vaugly recall the 8086 version
ran in 512KB of memory. It was a pretty decent system for the time; Xenix
makes me itch.
Where you would find Venix/86 or Venix/286 these days, I have no idea.
Someone has Venix for the DEC Pro on-line, so anything is possible.
If you aren't tied to Unix-like systems, earlier versions of OS/2 did very
useful things on i286 machines.
Ken
While not directly germane to vintage computers, I can see that this might
have some real interest for those restoring old displays.
I've got an old (1990) 120w-per-channel receiver in which I've just
replaced the hybrid power amp module--I think I can expect another 15 years
or so of life out of it. What bothers me is that some of the incandescent
12vdc back-of-panel lamps are starting to go.
They're soldered onto small PCBs and are the small 25 ma variety. They
illuminate the back of small LCD displays that have an orange filter on
them, so the color is basically that of an NE2 neon.
I was thinking of replacing the lamps with high brightness LEDs and current
limiting resistors--since the bulbs are paired up, I'd put the 2 LEDs in
series with a single resistor.
Now for the questions:
1. Has anyone tried to do this?
2. Will LED's have sufficient brightness and dispersion to substitute for
incandescents in this application?
3. What would the best LED to use?
Cheers,
Chuck
