That is my question.
I have used a couple of versions of the SCSI2SD boards in the past with
Viking, Emulex QC07, DEC RQXZ1 controllers in the past, and also direct
connections to MicroVax SCSI buss's.
There are other manufacturers of these SD to SCSI emulators now. What is
the current SOA? What works, what doesn't work with DEC hardware?
I have an ongoing project to restore a Datapoint 2200 version II and in the
process of doing so I created a small simulator for it to understand it
better. The simulator is now in the condition that it runs the cassettes
that I try on it quite well.
The simulator compiles on Macos and Linux.
A short movie clip when it is running:
Having a simulator for a 2200 if there is no software around is no point.
There are some tapes on bitsavers.org and a couple of other collectors do
have cassettes that can be read.
But is there anyone else out there that is sitting on tapes for a Datapoint
2200 (or 5500, 6000, 6600)?
Tapes can be read on a normal mono audio cassette tape recorder and fed
into a PC which samples the signal, preferably at 44100 kHz with 16 bit
resolution. It is important to not overdrive the input of the computer so
that the signal becomes a square wave.
Viewsonic 22 inch VX2262wm widescreen LCD
VGA up to 1680 x 1050 resolution, VIDEO Response as fast as 2ms.
Viewsonic LCD VX2262wm (brochure)
It was apparently indeed in a self-test mode.
When I fed it, it actually worked well.
When I looked at it using my video configuration in KDE on Debian 12,
it claims to be a Viewsonic VX2262wm.
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?
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:
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
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!
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
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.
The Old Calculator Museum
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
Sorry, my mistake - I meant the CCTALK archives at: classiccmp.org
Search "Dave's Old Computers" see "my personal" at bottom!