G'day!

[Darren]

Hi Folks. I was an old Pulsar electronics tech back in the day, but that was a few decades ago now  . Actually ended here looking for a photo of the Pulsar LBB - not something that really seems to be anywhere. I do/did have one in storage. I left a working LBB system, hard disk, and 8" floppies, but I later found out later my mother in law tends to "clean up" and tends to throw out things she doesn't understand (!) so I don't have much hope of ever seeing it again.

It was definitely a blast working there!

[MbeeTech]

G'day Darren.
Welcome to the forum.

You will find that we have a number of items in the Repository (access granted this morning) in the Vintage->Pulsar section. In particular, we have photos of the LBB (top and bottom)
in the Vintage -> Pulsar -> Pictures folder.

I never had one, but was always impressed with the LBB in the adverts etc.

[Darren]

G'day Darren.
Welcome to the forum.

You will find that we have a number of items in the Repository (access granted this morning) in the Vintage->Pulsar section.  In particular, we have photos of the LBB (top and bottom)
in the Vintage -> Pulsar -> Pictures folder.

I never had one, but was always impressed with the LBB in the adverts etc.

Thanks! it was one of those weird things. Me (17yo) built the LBB from the articles in ETI (hey, maybe where that's where I can a photo!). Built it and it ... didn't work in any visible way!

Turned out they were renting a space in the old 'Chicko' foods plant in Tullamarine, VIC - just up the road from home and near my favourite fish&chip spot! I gave them a call begging for help and they asked me to bring it in for a look. I have no idea at the time this was finding a unicorn - they must have had hundreds of people calling for help, but they were willing to help. Anyhow, I took it in, they looked for a few seconds said "Nice idea using sockets, but those sockets are crap! Pull them out and solder the chips in".

So I did (remove several dozen wipe sockets, used machine pin for the Z80 and eeprom) and everything works! A massive load of my extremely poor student mind. I'd turned my old RCA COSMAC 1802 into a terminal for the LBB (wirewrapped 80x24 video card!) and going back would be difficult). So I gave them a call and said thanks. They said they'd like a look at the LBB if I was in the area. Dropped in and showed them the board. They offered me a job on the spot - finding people who could solder cleanly and needed part time work must have been hard. 'Lucky' Phil Delacrataz I think. Best boss ever!

Having said that, this is your forum - so I have a quick Microbee-related question. Turns out I do have a distant Microbee connection. Back in the late 80's I was working for a company in Carlton VIC doing theater ticketing systems as a programmer. They needed an computer to embed in the system and, by this time, Pulsar was history. So I suggested we get you guys to do a partial depop of the keyboard (ISTR) for the production hardware because we'd written the app using it as a dev system and that solved a whole lot of effort for our tiny company. Anyway, turned out they were dodgy and I ended up resigning soon after. I should have known any company run by an ex-Collingwood president was likely to be a problem  . 

Do you recall if they ever got anything done by you?

Also I liked your hardware more than Pulsar's in general. The LBB memory timing being set by a cap on a TTL output. SMH.

[ozholmes]

Perfect timing....

I've been trying to resurrect my LBB system (along with a home brew S-100 system) for a few weeks now and we ran into the dynamic CAS timing being set by a capacitor (or spikes on the CAS being removed by the same capacitor !) - we had to increase the cap by 100pf as the new (much faster) RAM was being trigged by the logic spikes that were being created by the address decoding..... Several days later I twigged that sticking the oscilloscope probe onto the CAS line was stopping the random memory errors, as away we went

Only now I am stuck with the Floppy Disk Controller. I think the WD1691 Floppy Support logic chip is misbehaving - it's not changing the read clock frequency when switching between single and double density modes, and hence the FDC cannot get a good read of the flux transitions. But I don't what to go searching for this (relatively rare) IC unless I know it's the problem. It's a pity you don't still have an operating LBB, as it would be helpful to see some oscilloscope traces of the read clock and VCO control during normal disk operations

we should probably move this thread over to the "Non Microbee Vintage discussion" forum

OzHolmes