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A visitor from Sweden! - Crud3 - 11-07-2020

Hello everyone! My name is Anders and I live in Sweden!
For whatever reason we here in the cold north really took to the Microbee and we used it at school!
Just recently I have gotten hold of one together with a dual diskdrive and have started restoring it!
The next step is to find some documentation and software to write to disk and use the Microbee as it was intended! So i came here to find kindred spirits and get some help and also browse your repository!

Just thought I would post some pictures of my newest baby!

[Image: 357938603-caaf4449-f9c0-4d93-8ddb-ccb0a50b4195.jpg]

The rear looks a bit wonky as there are two connector holes on the left by the power/video/cassette on the top half but only one on the bottom half... unsure if this is due to a previous owners attempt to restore!

[Image: microbee-1.jpg]

And on the bottom it says Model II but this as well is a bit of a mystery to me as I have found no mention of this on the interwebs!

[Image: microbee-2.jpg]

And finally the diskdrive... Model SBC-01... 

[Image: 357938316-7c5796e4-a74f-425e-ac3a-87e1fc7a7fdd.jpg]

RE: A visitor from Sweden! - ChickenMan - 11-07-2020

Hi Anders and welcome to the forum Smile
I've seen these 2 on Tradera and have watched as the price has fallen over the past months, postage to Australia was exorbitant unfortunately so glad you have picked them up Smile Nice pictures by the way Smile

The case did go through a few minor variations and the miss-match may have occurred normally, I have seen that before but suspect the bottom part of the case is from an older Microbee. The Model II on the bottom is on EVERY Microbee case, that bit was never changed even right up to the last Premium models. Can you take the top off the 'bee and take a picture as that will tell us exactly what model you have, I suspect its a standard 128k Microbee Smile
The Floppy drive case was the first of that kind. Very heavy as power supply was built around transformers and some large capacitors, which may need replacing. Check before powering it up. Later models had switch mode power supplies.

We have everything you need in the Repository regarding software and documentation, just go here https://microbeetechnology.com.au/forum/showthread.php?tid=15 . Any problems just ask Smile

RE: A visitor from Sweden! - someone - 11-07-2020

Welcome aboard Anders.

Be prepared to to fix faulty keyswitches.

From memory, the front bezel is for Hitachi drives.
Later revisions had the disk drive cutouts changed later to accommodate other brands of disk drives such as Mitsubishi.

Be careful when servicing the power supply. It uses mains voltages.
The capacitors tend to dry out and their capacitance decrease.

All the power supply does is provide +12V and +5V for the disk drives, and +10Vish for the microbee often using a diode bridge to drop the voltage and make a small heater.



RE: A visitor from Sweden! - Crud3 - 11-07-2020

Hi all and thanks for the warm welcome and dire warnings (keyswitches are my nemesis...) and greetings from Sweden!!!
I have no idea why it came to pass that the Microbee got so popular here, on the other side of the world but there you go...
Back in 1980 I got my start on the Swedish ABC80 computer and about 2-3 years later I got my first look at the Microbee!

My plan is to start the Microbee on its own using a lower voltage power input, say 8-9 volts just to see how that goes!.
If that works then I will get started going through the diskdrive PSU... probably needs recapping!  Dodgy
I have a black belt in exchanging filtercaps though, as that has been the trend through almost all my retro computers!!

@ChickenMan - So the Model I was the kit-version and then the prebuilt version was the Model II presumably? Will snap some more pics later!
@someone - Keyswitches... have renovated many different keyboard types by now! Apple II, BBC B, ABC80 and ABC800! Next up... Microbee!  Big Grin

RE: A visitor from Sweden! - ChickenMan - 12-07-2020

The Original Kit was just referred to as that, original Kit that started Feb 82. Then by August 82 they had the new case design, which they should have printed design 2, not model 2 as the first fully assembled bees sold had the exact same components inside compared to the original Kit. There is a nice procedure on Keyswitch revival in the Repository also.

RE: A visitor from Sweden! - Crud3 - 13-07-2020

Ok... Just got the cover off and took a couple of pictures... It was remarkably clean inside and everything looks nice and neat!

First the coreboard:

[Image: 2020-07-13-11-13-58.jpg]

And then the motherboard:

[Image: 2020-07-13-11-16-50.jpg]

Note the Swedish keyboard on this one and also that the bottom part of the case is the correct one and the mismatched part is the top part with the space for what seems to be an extra DIN plug!
I will now solder up my Power/Video/Cassette cable and try to run it on 8V first and then I will have a look at the PSU in the SBC-01...  Smile

RE: A visitor from Sweden! - ChickenMan - 13-07-2020

Yes nice and clean, looks great. An early 128k SBC that matches the floppy drive box, nice Smile

We have a Swedish boot disk for that system also in the Repository.  It also has ABC80 Basic Ver 1.55 on the disk.  It runs and you can type in a simple Basic program that also runs.  BYE get you back to CP/M.  But without an ABC80 Manual, not sure it his is an un-modified version or one specially adapted to run on the Microbee.  Boots to


If your 8v power source is a switch mode variety, just be aware that some may switch off as the large orange 4700uf cap can drag so much power initially that the switch mode thinks its a short circuit and turns itself off.

RE: A visitor from Sweden! - Crud3 - 13-07-2020

So I just finished the Power/Video/Cassette cable and modified the powersupply to give out 8V!
I didn't have a composite monitor where I am at right now so I connected the Microbee to an HDMI monitor through a Composite to HDMI converter!
Then I powered it all on! I got a signal at least but the following video shows the results... not what I had hoped for!  Sad

I also tried changing the output power to 9V as 8V might not be enough but got the same result!
Any ideas where I should start looking?

RE: A visitor from Sweden! - ChickenMan - 13-07-2020

Getting the solid block top left corner is what you get when there is no floppy attached. So that indicates the unit is working and trying to boot a disk. If you hold down the M key and then use the Reset key it should jump into the inbuilt Monitor. Type in E e000 and that will Examine at address E000h which is where the boot rom resides. All that interference I doubt is coming from the bee.

RE: A visitor from Sweden! - Crud3 - 14-07-2020

Ok that is good to know! Smile
I tried getting to the Monitor by holding M and pressing Reset but nothing happens...
Makes me wonder if this is the keyswitches acting up or something else! Are there any other shortcut keys that I could try?
Otherwise I will check the PSU in the disk unit and try to write a boot disk to get somewhere were I can test the keyboard!