Joining the conversation

[CheshireNoir]

Well you'll never guess it, but I finally have a Microbee.
Better yet, I have a Microbee and two "for parts" units.
The "complete" unit even came with a box. It's a 32k Series 2. Looks to be in reasonable nick, although no power supply or video cables so I'll have to make those up.
I have a second unit, no idea what model or make. No top cover. Otherwise seems complete.
The third unit is just the motherboards and the keyboard. Seems to have a lot of empty sockets so it may have been "pillaged" in the past.

I can see I have a lot of fun ahead of me :-)

Chesh

[ChickenMan]

Well done and welcome to the Microbee owners family at last The 32k Series 2 are great unit, plenty of spare sockets to put in EPROMS with some of your favorite games that can be instantly played rather than wait for them to load via cassette.

The other 2 units will be great for spares, particularly the key switches that notoriously fail with time. Post a pic the the 2nd units coreboard and we should be able to tell you what you have.

[CheshireNoir]

I dumped some pics on my Blog
https://ilike8bits.com/2021/07/20/the-new-haul/
As it says in the post, I guess I have a visit to Jaycar in my near future :-D

Chesh

[ChickenMan]

The uncased unit is a 32k and if I can read the coreboard model as 8328-4, that makes it a late model PC85 and missing a few roms. The part cased one is an early 16k unit with one Basic A rom missing. What freq is on the crystal just above the 9 key ? If its 12.0, as I suspect, it an early 2mhz bee rather than all the others that followed that were 3.375mhz.


Edited.

[CheshireNoir]

... the part cased one is an early 16k unit with one Basic A rom missing.  What freq is on the crystal just above the 9 key ?  If its 12.0, as I suspect, it an early 2mhz bee rather than all the others that followed that were 3.375mhz

The crystal seems to be 12 MHz, so yes. 2MHz Model. (At least, all I can see poking out is the 2.00 with the rest cut off by the Keyboard)

Cool! Thanks for that! Interesting to know.

Chesh

[ChickenMan]

I edited my earlier post, the loose bee board appears to be a PC85b which is a much better and later unit than the Series 2.

[CheshireNoir]

Well the good news first. Making the cable was relatively easy...
Initially I couldn't get any of the three to boot at all, which was a bit disappointing. I ended up opening up the sealed unit, which also turned out to be a good thing as the battery inside was just starting to corrode. This also revealed the top board had come loose from the baseboard. I reseated the baseboard and it booted! The keyboard is... about what i was expecting. All the keys seem to work, with a bit of force, so that's something :-)
I still haven't got any life out of either of the other boards. (No beep, no signal) I suspect I'll need to break out either the logic probe or the 'scope to get any further with them.

How do people work on these with the two boards? I can't possibly probe out the lower board with the upper board in place... Lots of Dupont leads?

[RedskullDC]

How do people work on these with the two boards? I can't possibly probe out the lower board with the upper board in place... Lots of Dupont leads?

Hi Chesh, et al.

Glad you're having fun with them!
There are some right-angle adapter boards which allow you to have the coreboard sitting vertically, so as to work on the baseboard.

Other than that, yep, a lot of dupont leads!

Cheers,
Leslie

[ChickenMan]

Arr some success, great.  As mentioned before the 16k bee in the 1/2 case is missing a BASIC rom therefore will NEVER boot until its replaced.  You may be able to get the Monitor if you hold worn the M key while using the Reset key held down for a few sec.

As for the Right-angle adapter, check out 8307_4_expansion_board_set_pcb.zip in the Documentation/PCB folder, you might be able to build your own

[ChickenMan]

I've split out the PC85 discussion to a new thread in the Hardware folder - see https://microbeetechnology.com.au/forum/...hp?tid=367