< Does anybody have any information on a North Star Horizon? I may be
< acquiring one of these soon but don't know much about it except that
< it has wooden side panels and used to support a half-dozen terminals.
< Is it a S-100 bus?
Yes, I have one I built (and still use!) 20 years ago! Exteremely sold
piece of s100 hardware.
The top is wood too! Z80/S-100. Support for more than one user means
it was running a timeshare version of NS* Basic.
Allison
Hello,
I just joined the list. While I don't have any specific questions
_at_this_point_ :-) I have quite considerable experience with
electronics and am willing to help out where I can (time permitting)...
Of course I am always interested in software for my collection.
A quick list:
ZX81 with "real" keyboard, and of course 16k pack
TRS-80 model 1
Vic 20
C64
SuperPET with 4040 drive
Rainbow with 10Meg drive
Northstar Advantage
Bits'n'pieces of 2 PDP-11's (-23 and -73(?))- enough to have one
working in debugger mode
- no drives or anything
MicroVax II with periphials, had it running Ultrix and NetBSD
HP 75D and a few old HP calculators
128k Mac and Mac Plus
The next two are my everyday use computers. Dubious if they count as
"classics"...
Amiga 3000 (AmigaOS 2.04, and NetBSD until the HD with the root
partition went south...)
SparcStation 1+ running NetBSD
(NOTE: those are my home computers. Needless to say here at work I use
the usual unspeakable... though occasionally I do reboot my computer
into FreeBSD - but then I can't receive mail from the $%#& exchange
server)
I am hoping to aquire a (brand unknown) S100 Z80 box in the next few
days...
Joachim.
jpero(a)cgo.wave.ca wrote:
>Early high end Dell series (I think!) had this dot matix that glows
>yellow and rare motherboards that had POST display built in.
Back in those days, they were known as PCs Ltd. I had a 286 like that.
- John
Jefferson Computer Museum <http://www.threedee.com/jcm>
Here's a couple more for the TRS knowledgeable.
>from a TRS novice.
1. Among the various TRS stuff I picked up recently was a
TRS-80 monitor. It has a similiar connector coming out
the front as the Model II. Was this the for the std. M.1
and M.3 ?
2. Included with a TRS CoCo 1 I picked up last summer was
an adapter plugged into the cass.port. a label "TotalCommunications"
on one side and "Telelearning" on the other. Into this was plugged
another M/M adapter labelled " RS232 Gender Changer" Was this for
hooking up a fdd and/or modem ?
ciao larry
lwalkerN0spaM(a)interlog.com
> Could you tell me just a bit about the DL8? What does it look like, does
it
> work, any software... manuals?
I have no Doco or software for the DL8a, from memory there may be something
in
ROM, but I know that some of the ROM sockets are empty. It is contained in
a
single 19" rack mount case, mainly made from aluminium. On the back panel
there
is the fan, the power connector and a single female 25 pin D connector (I
think
it's a current loop port). The front panel is white with black lettering.
All
switches are toggle swicthes, some have red hoods, some have blue. I think
there are seperate banks of switches for address and data as well as the
usual
halt, run, examine, etc. All the LEDs are red. I have powered it up and
watched it count in binary, but as I don't know 8080 and have never
programmed a
front panel system I haven't done anything else
Does this ring a bell for anyone?
A
<Pardon my ignorance, but what's an R6500? That wouldn't be an IBM
<RISC machine, would it?
No, non-ibm as it comes. It was the series of chips starting with the
6502 that wree used in the apple series, AIM, KIM, PET and Commodore
machines. The number of hands the licensed 65xx chip design passed
through is somewhat record as well!
Allison
<a) What should I be looking for in a logic probe. Any recommended model
<(say, <$100)
Unless the logic is fast (altairs arent!) any will do.
<b) Ditto for multimeter.
My favorites are a fluke m12 (digital) and a triplite-160(analog).
<c) Where can I find a brain? :)
think about it for a while ;)
<I have it firing up and basically behaving, but some LEDs don't light whe
<they should, but are definitely able to light when they want to.
Nominal altair misbehavour. Several problems very likely some age and
some design related. Switches are not making(corrosion internally),
operating them may clean them up or replacement may be needed. Check with
low current/voltage continuity tester(fluke m12 is good here). The pannel
uses oneshot timers by the carload (74ls123 and friends) and they can be
flakey. The mother board connections can be nasty from using solderplated
edge connector board with gold edge (electromigration). The board edges
can be cleaned with eraser but most systems with that disease end up with
shake well before using (pull boards/reinsert to wipe contacts).
I highly suggest this for any kit constructed altair pannel:
1. get drawings/schematics
2. clean well
a. remove and disassemble to just the board with no hardware.
b. Wash (yes really!) in dishwasher (best done when wife is not around)
using some of the normal dish washer soap.
NOTE: this will remove grime and any flux residues that may over time
have become conductive or corrosive! We have no way of assuring
a kit was constructed with quality solder/fluxes.
c. dry well using WARM oven at 120-140F.
(alternate is to soak in pan of 90% or greater isopropanal and air
dry. NOTE: ISOPROPANAL IS FLAMMABLE)
3. Inspect and resolder any questionalble joints, use care.
4. Reassemble partially, to allow testing.
NOTE: ONE MOD IF NOT DONE IS STRONGLY SUGGESTED... The 8800 front panel
design has 120vAC power on it and that was/is very bad practice.
As implemented it is a safety hazard and also a risk to the
hardware. It is best to keep good distances between mains power
and logic! Rewire so that the front pannel power switch is not
connected to anything and mount a replacement in a protected spot
on the rear pannel.
I feel strongly about that, even as a museam peice it should be done. The
existing switch can be left in place for appearances.
Allison
<A
<
<>Hmm... I've yet to find a classic computer fault that could not be
<>tracked down using 3 things - a logic probe, a multimeter (DMM/VOM) and
<>a _brain_. On the grounds that my brain isn't that good, I sometimes hav
<>to use other test equipment, but when I finally do track down the
<>problem, I generally realise that the symptoms were obvious from the
<>start if only I'd realised what they meant.
<
<
<I may be in the running to buy an 8800b turnkey model which (sigh) doesn'
<have the nice front panel that you describe for the 8800b. Can you tell
<me how the turnkey works? Does it have a ROM'd bootstrap loader? Will
<be able to program it if I don't have drives?
The fronpanel less version of the MITS was the 8800b (turnkey) and it was
generally configured to boot their disks. There may have been boot options
for cassette or papertape boot as well.
Allison
A few weeks ago, I turned down an offer to get an IMSAI and Altair
system, reasonably intact, both for $500. What do I know. :-)
Looks like a market ripe for wheeling and dealing.
These online auctions are an interesting phenomenon. At first I thought
they'd be a great place to pick up contemporary and antique computer
stuff at good prices, perhaps with a few "sleeper" bargains. But the
info flow is too good; it's my impression that prices are consistently
driven *higher* than I'd regard as "street" price. Good news for
people running auction services that take a percentage.
- John
Jefferson Computer Museum <http://www.threedee.com/jcm>
Did anyone besides me notice that, judging by their ad in the latest
issue of Computer Gaming World magazine, the software division of
Metro Goldwyn Mayer (MGM INTERACTIVE INC.), producer of the original
"Wargames" motion picture, doesn't know the difference between an
IMSAI 8080 and a TRS-80? Their ad goes something like "In 1983, a
teenage computer hacker almost destroyed the world with one of these:
[picture of TRS-80 Model 1, with caption reading 'TRS-80, 4K RAM, no
hard drive']". It goes on to talk about how much damage he could do
with today's computers (go figure), and introduces their new
"Wargames" computer game. Maybe the marketing department should jog
down to the film vault and watch the movie, because _it_ used an IMSAI
8080 with a piece of paper stuck over the name for the young
"hacker's" computer. Sheesh.
-Bill Richman
bill_r(a)inetnebr.com
http://incolor.inetnebr.com/bill_r
(Home of the COSMAC Elf Simulator!)
