FreeBee Premium, a free open source Microbee Premium clone

[Suzyj]

If you're Australian, and a codger like me, you'll probably remember the Microbee, a little Z-80 machine with a really good basic, reasonable graphics, and (in later models) CP/M.

They're ridiculously rare and expensive these days, not to mention clapped out and unreliable.

To fix both problems I've developed a new one. It's 100% through-hole, with no special PLDs or other mechanisms to lock it down. It runs all Microbee software just like a later one, in full and glorious 16 colours. There's a design for a multi-rom board (SuperPAK) if you prefer a ROM based machine, plus a board with Compact Flash that runs CP/M, treating the CF card as a hard disk.

It's really easy to build, made with parts that aren't super hard to get, and heaps of fun.

Go check it out at the Microbee Software Preservation Project:

https://www.microbee-mspp.org.au/forum/viewtopic.php?f=96&t=3130

[Suzyj]

The construction notes do a pretty good job of describing what it's all about:

https://drive.google.com/file/d/1Y0UfahO4kn7-HrOwvS-JiWSZYfDxNQId/view

[Halcyon]

Thanks for sharing!

I remember my cousins had a Microbee (can't remember what model) but it ended up getting tossed in the bin. I look back at all the old computers I had that just got thrown out and it makes me sad. Old Sharp Z80 machines, an IBM PC, etc...

[Suzyj]

Yes it's amazing the things that we chuck out. In the very early nineties I extended my microbee at the time (a 32K one with tape storage) as a tech project with 512K RAM, a floppy disk controller, and real time clock by building and hand etching a new coreboard. I remember hand-drilling every single via, and threading wire through the holes that was soldered both sides. Then I grabbed a disk drive unit from a Dulmont Magnum, of all things, and had a CP/M machine.

A couple of years later that all went in the bin during a house move. If I knew then how nostalgic I'd be in thirty years I'd have kept it.

Not that it really matters so much. Real microbees are getting almost impossible now to use, as the keyboards have little conductive rubber bits that just don't work any more.

[CatalinaWOW]

I face the alternative to chucking that "too good to trash" stuff out.  Literally hundreds of kilograms of stuff that I will never have time to play with, and the few times that I have gone back a revived one, it isn't as much fun as I remembered. 

[Kean]

Very cool project Suzy.  I'm certainly interested in PCBs, and I should have at least some of the parts already.

I have some ex-school Microbees in a box under the house that must be 40 years old now.  I have not checked on them in a while, and I recall they were not in very good condition when given to me.

I also have one of the Premium Plus kit I bought from Ewan in... wow 2012!  So that has been sitting in its box for over 10 years and I still have not got around to assembling it.

[cfbsoftware]

I have some ex-school Microbees in a box under the house that must be 40 years old now.  I have not checked on them in a while, and I recall they were not in very good condition when given to me.

Now would be a good time to check on them - nine different lots have actually sold on eBay in the last 3 months for an average price of about $550 per system.

[Kean]

Now would be a good time to check on them - nine different lots have actually sold on eBay in the last 3 months for an average price of about $550 per system.

Yeah, the sold price is pretty amazing for some listings.

These are what I would consider "barn finds", and were not well stored even before I got them.  I am pretty sure all of them are non-disk low-end models (ex classroom), but I think I may have a "computer-in-a-book" system stashed away as well.

My TRS-80 collection is in better shape, and I have various other devices of that era like a Sharp MZ-something.  I've been kind of hanging onto them for my "retirement", but I probably have collected a few too many...

[Suzyj]

It might be best to sell the parts rather than the whole systems.

The later school systems were generally a non-premium (monochrome) main board with a stripped-down floppy coreboard, without the floppy controller. They ran code that booted from a server using a parallel port connection. They won't do much without the server.

In order to make them work, there are a couple of options:

1. add the missing parts to the coreboard (WD2793 FDC and support bits) which will make it into a normal CP/M system, and boot from a floppy drive.
2. replace the coreboard (the one on top) with something that works. I developed SuperPAK and the Freebee CF coreboards for just this.

Even so, the keyboards will be completely cactus, so there'll be a bit more work.