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Please note also - THIS BLOG ENDS HERE WITH THE LAST ENTRY FROM NOVEMBER 9th 2021.

I have prepared a new blog with wordpress at https://vintagecomputing.info !!!

Thank you.

Do you remember the time a scientific calculator was (very) expensive ?
I am not really a collector of these vintage calculators, but some are very interesting and also unique. The first mass production LED display based calculator was the Texas Instruments Datamath 2500, and luckily I own also one (which I bought at Ebay a few years ago, still not too expensive).
Later, many real famous models (also from HP) were sold, e.g. the TI-57, TI-58C and the Rolls Royce of these all, the TI-59 with magnetic stripe reader.
In the next time, I will introduce some here, starting with the TI-45, which was not too common also because it has a green VFD (Vacuum Fluorescent Display),

This one has basically a set of common scientific functions, but can't be programmed.
The calculator case is comparable to the cases of the TI-57/58/59 series.
For me, it's a very beautiful one (due to the green display).
Unfortunately most of the time you buy nowadays such a vintage calculator, the battery pack is destroyed by battery acid (from the NiCD cells).
For these who are looking for a replacement, take a look >here<.

A real interesting page is also >datamath.org<.

There will be something new I didn't expected... a new device was developed from Jim Drew (he already developed a lot of cool gadgets for the Commodores), which may supersede the Kryoflux device (you know it - the magic pcb/box which could read almost every floppy disk format).

It's much better than the Kryoflux:
It uses a 25ns capture resolution, where Kryoflux uses a 41.66ns resolution.
So, copies and images made with SuperCard Pro will be much more exact.

Take a look at his website to follow his news about it !

This is it what the new pcb looks like:


If it costs less than $100, it will be a success for sure.

I own an old but beautiful Intel 486 based notebook, a Siemens PCD-4ND with a build-in floppy drive (a Citizen W1D). This drive is removable.



Unfortunately the floppy drive is not working reliable enough anymore.
So I had the idea to repair it, and I had to open it:



You have to remove the plasic case (fixed with 2 screws), then a metal sheet (fixed with 4 very small screws)...



... and you can recognize now a missing tension for the belt:



To get the belt out of the drive, you have to lift the motor also (2 screws).
The dimensions of the belt are: 220mm circumference (110mm x2, as shown in the picture below, that means a diameter of 70mm), 1mm width and far less then 1mm thickness.



As you can see, I marked a red dot in the third picture, may be I can place there a small bumper to increase the tension of the (old) belt.

I have NO IDEA where to get such a belt. Seems to be very difficult.
If someone has an idea where to get such a plastic belt, let me know, thanks in advance.
Others already looked for some and had no success (see related link)...

Very nice project, the Mini80. A real Z80 CPU is used (this is important for speed and compatibility), but all I/O is done by a Parallax Propeller chip.

Very small footprint, simple logic board design ... what else (except a build in VGA interface) do you want ?
This is a picture from the prototype board:


And this is the related CP/M boot screen:

It can run CP/M 2.2, using disk images from a larger "pack" file.
Hopefully his transfer utilities (for single files) will be implemented soon.

Just take a look at the Micro Vibe Site and that Mini80 article
http://www.shaels.net/index.php/mini80/ ... o-overview
for an introduction.


I recommend visiting his site (see also "related link") !

Because NSA will use too much energy to wiretap aka get the data from all the people around the world (even from the ones who are NOT evil), I propose a standardized interface for all future devices, so it will be much easier to have all the data stored in Fort Meade.
This needs a logo certification program also, so we (all the people who are being wiretapped) know in advance that the devices or software solutions are 100% compatible with that above suggested interface. I also made an easy recognizable logo for this certification program:

Next time you buy electronical devices or software, be sure to get a certified "PRISM ready" one !