Peter's z80.eu site blog
New toy: Texas Instruments LED/VFD Display Calculators (1972 - 1980) 
Sunday, October 27, 2013, 04:14 PM
Posted by Administrator
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<.
add comment ( 162 views )   |  permalink   |  related link   |   ( 3.1 / 2338 )
Successor of Kryoflux - the new SuperCard Pro from Jim Drew ? 
Tuesday, October 1, 2013, 11:00 PM
Posted by Administrator
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.

5 comments ( 283 views )   |  permalink   |  related link   |   ( 3 / 2869 )
Notebook floppy disk drive repair - an impossible mission... 
Saturday, September 7, 2013, 12:00 PM
Posted by Administrator
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)...
add comment ( 165 views )   |  permalink   |  related link   |   ( 3.2 / 3415 )
Interesting Z80 project using a real Z80 but for all I/O using an MCU 
Tuesday, August 6, 2013, 09:19 AM
Posted by Administrator
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") !
add comment ( 136 views )   |  permalink   |  related link   |   ( 3.2 / 3479 )
NSA compatible devices/software .... easier for customers to get them now ;-) 
Friday, July 19, 2013, 07:50 PM
Posted by Administrator
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 !

add comment ( 137 views )   |  permalink   |  related link   |   ( 3.1 / 4841 )

<<First <Back | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | Next> Last>>