I was given a 22-inch Viewsonic monitor. The label had been scratched
off. It has four switchesd below the screen, labeled 1, 2, an up arrow,
and a down arrow.
When I plug it in, it flashes Red, Blue, Green, White at about one-
second intervals. Pushing the buttons doesn't affect it.
I haven't attached a VGA or DMI to it.
Is it irreparably broken?
Van Snyder
Hello,
As some may recall I have been working on getting a VT100 going again. I
have made good progress and I think the main board is probably OK now (see
here if you are interested:
https://robs-old-computers.com/2023/11/19/vt100-keyboard-constant-clicking-f
ault/). Possibly I still need to replace the NVRAM, but I am leaving that
until I fix the problem I want to describe next.
The problem is that there is no image on the screen. This is because the
monitor board is not doing anything, there is no glow from the neck of the
tube etc. I have found that this is because the fuse on the 12V input to the
monitor board is open circuit.
Of course the worry is, why? There could be a fault on the board. I have
tested the transistors in circuit with a multimeter and they appear to be
OK. I used a bench PSU to give the board 12V and it drew no current (with
all connectors disconnected). I tried again with the round connector
attached to the end of the tube and it drew about 100mA and there was a
faint glow from the neck of the tube.
I am hesitant just to replace the fuse and try it. I am hoping for some
suggestions on how to test this safely (in particular without involving the
flyback transformer) to find if there is a fault.
For information, the monitor is an Elston and I pre-emptively replaced all
the electrolytics on the monitor board apart from the non-polar one. Some
details of what I did are here
https://robs-old-computers.com/2023/10/01/vt100-ram-fault/. Although I have
since realised that I didn't replace two of them because they looked like
diodes. I don't think the board I have is the one in the available
printsets.
Thanks
Rob
On Nov. 15, 1971 Intel commercially released the 4004 microprocessor which
some consider to be the first. Nonetheless, even if not in agreement, it
made possible the instrument which drives the classic-computing industry or
at the very least our hobby!
Happy computing.
Murray 🙂
Steve Lewis wrote:
> then like the 4004, we're struggling to find evidence of actual products that
> made use of them. Wasn't the 4004 used in some cash registers, street lights, or > some weighing machines? (I don't have any specific references, just recollections > from past reading)
The major (and primary reason for the 4004 and the MCS-4 family existing in the first place) was Nippon Calculating Machine Co and their Busicom 141-PF electronic printing desktop calculator. NCM went to the US looking for a chipmaker (the capability for the level of integration required to make such a chipset did not exist in production form anywhere else in the world at the time), and two companies were engaged to develop a chipset for NCM, one being Intel, and the other being Computer Design Corporation.
As history clearly points out, Intel won the competition, developing a chipset based on the 4004 CPU, and some peripheral chips (RAM, ROM, I/O) that ended up being the operating element of the NCM/Busicom 141-PF
Calculator.
The 141-PF is a very famous calculator for this reason, but is otherwise (by appearance and function) a very ordinary calculator for the time. The fact that it had "Intel Inside" (though the term didn't exist at the time), using the world's first commercially available microprocessor chipset made with MOS Large Scale Integration technology, makes the 141-PF (and the OEM copies; the NCR 18-36 and the Unicom 141). Two versions of the machine were made, one that was a four-function machine, and another that added an extra ROM that added a square root function.
Other devices were subsequently developed that used the 4004 as their computing core, such as digital scales, electronic cash registers, and various other electronic devices.
This was only possible because initially, Nippon Calculating Machine Co. had exclusive rights to the use of the chipset. Due to some financial difficulties, NCM renegotiated the contract with Intel, removing the exclusivity clause in return for Intel forgiving some money owed on the development of the chips. This allowed Intel to sell the chipset to the open market. Once this occurred, Intel aggressively marketed the chipset as the MCS-4 microprocessor system, providing extensive documentation, development tools, both hardware and software, and lots of support for anyone wishing to develop an electronic system based on the 4004.
The Busicom 141-PF calculator and its OEM versions were the first commercially-available electronic devices that had a general-purpose microprocessor with firmware implementing the machine’s logic, and thus represent the historical benchmark.
These were actual products that were sold under the Busicom brand as well as NCR and Unicom. It isn’t known how many of these machines were actually made, but enough were made that they can still (rarely, though) be found today. Nippon Calculating Machine Co. in Japan manufactured and distributed them under their Busicom brand name, as well as providing the machines with subtly changed color schemes for cabinet/keyboard to OEM customers, which would market, sell, and service them under their own brand names.
Rick
--
The Old Calculator Museum
https://oldcalculatormuseum.com
P.S. If anyone out there has one of these calculators lying around gathering dust, working or not, and would like to have it see new life as part of a museum exhibit, please get in touch with me.
>>[anyone know if there's a usable web interface to CCTALK? I browse it
>>through the ARCHIVE on CCTALK.COM
>KenUnix - 27 Nov 7:13 p.m.
>When I try and connect to it I see in the tab chinese verbiage
>CCtalk ???????????-?????????????? and it tries to send me to
public.hujia.104.cdn20.com
Sorry, my mistake - I meant the CCTALK archives at: classiccmp.org
Dave
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>26 Nov 8:14 p.m.
>I was trying to format an HP LIF disk from IMD (77 tracks, 30 sectors,
>5 interleave, 512 MFM encoding, 256 bytes per sector). Which I can
configure
>IMD for using the interactive user interface. EXCEPT it won't
>accept entering sector numbering starting from 0 to 29. It always wants to
>start at 1.
>So it looks like it's just a trivial bug in the interactive user interface.
Hi Marc,
I'll look into it - it will take me a while as I have to dig out and set up
a real DOS IMD system...
[anyone know it there's a usable web interface to CCTALK? I browse it
through
the ARCHIVE on CCTALK.COM - it's a web interface which presents "reply"
button
- but it doesn't work - so I have to cut/paste/edit the existing post and
send
it back by email - and HOPE that it finds its way to the proper thread!]
Dave
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Search "Dave's Old Computers" see "my personal" at bottom!
Please fill out this pre-event survey for VCF East 2024:
https://bit.ly/vcfe2024pre
Thanks!
Jeff Brace
VCF National Board Member Chairman & Vice President
Vintage Computer Festival East Showrunner
VCF Mid-Atlantic Event Manager
Vintage Computer Federation is a 501c3 charity
Hi, this is "Dave Dunfield" - best known here for being the site owner of
"Daves Old Computers" and the author of "ImageDisk"
No longer have the email I used to use to access cctalk... (hence the
change)
Just in case anyone is interested:
I've been working on a "retirement" project:
I am publishing some 40+ years worth of source code to "stuff I've written".
This includes my DDS products, lots of "internal tools and utilities" and
other misc. "stuff". Of special interest to cctalk members, this include my
Altair, Horizon, H8, D6809, MOD8, ImageDisk and some other related
material.
Most of it is C (mainly for my own compiler - one of the items), some in
assembly, and a few "custom languages".
Available from my personal site:
https://dunfield.themindfactory.com
or go to: "Daves Old Computers" -> "Personal"
Please note that I no longer monitor these forums on a regular basis.
Anyone wishing to reach me, please see the "contact" link on my site.
Dave
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Search "Dave's Old Computers" see "my personal" at bottom!
Sorry if not linked correctly - looking through the list via the archives..
"reply" option doesn't seem to work (at least for me - older Chrome)
>but my understanding was that the 4004 and 8008 were effectively developed
>at the same time? And were announced or available about within one month
>of each other?
I believe they were, although I never had much experience with the 4004...
I did play a bit with the 8008 - and wrote a simulator/emulator for the
8008 system I had, a Canadian:
MIL (Microsystems International Limited) MOD8 (Modular-8)
it was also available as:
GNC8 (Great Northern Computers) 8008
You can get MOD8 simulator from "Daves Old Computers" and actually
experience
using an 8008 based system including the built in "MONITOR-8" ROM software
as
well as "Scelbi 8008 BASIC" (one of the earliest) - source to both
provided.
If you care to, I included ASM88 (my 8008 cross assembler) so you can try
writing and running 8008 code!
-Be aware that MOD8.COM itself is pretty old and is 16-bit DOS software.
This means it WON'T run under modern Windows, but it does work well in
DosBox (I recommend the one I have on my site)
Dave Dunfield - https://dunfield.themindfactory.com
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Search "Dave's Old Computers" see "my personal" at bottom!
Folks,
While looking for something else I found few iPaqs. There are two later
models, mud coloured with plastic screen covers both work fine. Sadly the
silver one with the battery has a broken clip, so you need to secure it some
how works if you do this. The one with the missing door does nothing. There
are two power bricks, one USB lead, one docking station. No stylus. Can't
remember when I last looked at these. Free collection from Manchester.
Dave
