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A rare ECB System: Elzet/P (Elzet-80 series) - Z80 portable in industrial case 
Sunday, November 25, 2018, 12:00 AM
Posted by Administrator
Today I want to show you a meanwhile really rare ECB Z80 system from 1982. It has a ECB-backplane, so many ECB-cards (like the important Z80 CPU Card, the RAM and the FDC-card, and last but not least also a VIDEO-80 (terminal) card) can take place.
The systems exists also in a desktop case, but this one has a "portable" case from Schroff.
Portable means, it has a handle to carry it, but it's unexpected heavy (~20 Kg).
The Z80 CPU runs with 4 MHz, and it has at least 64KB RAM (you can add more) and two quad density floppy drives with 800KB storage capacity.
Usually it runs with CP/M 2.2, which is not extraordinary for an ECB system.

I got the system with a broken power suppy and I had not enough space and also not enough time to repair and run it, so I swapped it against two Microprofessor MPF-1(B) with someone which has space and time enough (I can ask him if you like to exchange infos/expirience etc).
To get an expression how expensive it was, see the offer also from mid 1982:


If you look (=google) for further infos about this system, you will not find so much helpful.
If you're looking for a system disk, I can send you a TELEDISK image file.

Related link points to the wikipedia entry for ECB.
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Elektor SC/MP system, now the real pictures 
Saturday, November 10, 2018, 09:10 PM
Posted by Administrator
CPU (SC/MP 8A/500D aka INS 8050)

I/O board

keypad (self made, not the original pcb)


The related link points to the Elektor site with the related article overview.

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Elektor ("Elektuur") SC/MP - the real device and the emulator 
Thursday, November 8, 2018, 12:00 PM
Posted by Administrator
Somebody told me his father had experimented with the SC/MP processor many years ago, so I pleased him to look after this again. He found the "archived" boards, and now he handed over this to me. This is great, because the CPU is already about 43 years old, and very rare.
I will try to make photos from it, and also to run it again.
Unfortunately the first thing I have to figure out is what happened with the power supply, which looks a bit exotic and perhaps the capacitors are already died, too.

While looking for documents about the SC/MP, I found some hints about a website, which offered also an emulator. Unfortunately the author of the website, Sipke de Wal, already died in 2004.
So I tried to find it on archive.org and yes, I found something about it here:
https://web.archive.org/web/20050403201729/http://xgistor.ath.cx:80/scmp.htm
But the emulator can't be downloaded anymore (written in Visual BASIC 6.0), so if anybody knows where to find "Scmp09.zip", plz inform me.

Sipke wrote about the availability of the emulator in 2001, see also
http://www.verycomputer.com/44_e9dcb0c463ab0a0c_1.htm

Picture of the emulator:


The dutch Elektuur magazine from 1977 can be found here:
https://archive.org/details/Elektuur16319775

The archived english versions can be found here:
https://archive.org/details/ElektorMagazine
Look for the issues 11-1977 to 03-1978 for the SC/MP system itself,
later issues covering cassette interface and other extensions

A really nice photo can be found here: https://www.flickr.com/photos/eveliensnel/3115361201

Some other sites also referring to SC/MP related informations, see related link.

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Raped IBM PC/XT on Youtube, ignorance for details at it's best 
Saturday, October 13, 2018, 12:00 PM
Posted by Administrator
Some people might have cool ideas, also to modify originals for a new functionality.
If someone try to modify an original IBM PC/XT to implement a new PC in it, it might be still worth to mention it, especially if the conversion to a modern PC is subtle (not intrusive).
So if someone do this but let the PC still look like the original, and make it possible to use the original floppy disk drives (but with the modern hardware inside), it would be even cooler.

The opposite is ugly. If you destroy half of the original case (e.g. the backside) and if you just use the floppy drive bezel, but remove the rest of the drive(s), it sounds like a brutal modification, without any style.
And even more worse, they use the floppy drive bezels, but mount them reverse (upside down), see the picture taken from the Youtube video:


But judge yourself about the (not well done) conversion, see "related link".

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Finally I managed to re-activate my Central Point Option Board... 
Sunday, September 16, 2018, 10:00 PM
Posted by Administrator
It works now, but it was quite a high effort to get it running.
First, I had to figure out that a Compaq Portable has REALLY not much space inside.
I added first a 256KB RAM card, because otherwise some software can't be started with only 256KB RAM (on board).
But then I recognized that the original video (CGA) card was fixed with a horizontal arranged screw, but the hole for this screw was ONLY in slot #2.
In slot #1, the original floppy disk controller resides, and guess, the cables are really short. So to connect the floppy drives to the first version of the Central Point option board, I had to look for much longer cables, but with two old style shugart connectors and with an AT style connector at controller side. Because this was a pain to arrange it, I decided to exchange the A: and the B: drive connector (so the cable didn't crossed itself). Also, the original floppy disk controller is really "full height", so no space to arrange things more flexible.

Finally it runs, at least with older TRANSCOPY versions (2.x):


This is really tricky to arrange:


And this is the resurrected card (a 16MHz crystal was broken, so I replaced it).


It is even possible to copy special Apple II floppies, see related link.

Edited later: TransCopy 4.2 seems to be the last version which works with the first version of the Option Board (not the "Deluxe" one).
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