General Stuff(tm)

[rubber_jonnie]

Sometimes the system needs a soft reset to get itself working for some unknown reason with the PiStorm in the Lazarustorm, but after that it's completely stable.

Working fine now so I'm not overly worried :)

I may even get another A500 as I intend to keep my current one with the PiStorm as internal :)

I had to test the Larustorm out though :)

[stephen_usher]

Over the last week I've been doing model railway stuff rather than retro computing and today I've been trying to reproduce a station building by counting bricks in photos I took last December.

Looking up on Google apparently standard bricks with mortar are 225mm wide and 75mm tall...

Now, using that measure I then had to... (no. of bricks) * 223 -> convert to Imperial feet -> times by 4 to get 1:76 scale (4mm to the foot).

Trying to do this for all the dimensions just gave me lots of rounding errors and other scaling errors to the point where I was tying myself up in knots in Fusion 360.

Then I realised that 225mm is actually almost exactly 9 inches, which is 0.75 feet... which scales to precisely 3mm. Add to that, 75mm is near as damn it 3 inches, which is 0.25 feet, i.e. 1mm.

Suddenly all the calculations became simple. *sigh*

I can rejig all the Fusion 360 models tomorrow and reprint the "steel frames" with the correct dimensions this time!

[stephen_usher]

Well, it looks as though my Sinclair QL diagROM is coming in useful at last.

Someone on the QL forum has a machine which has a black screen when he turns it on. He's install my ROM and that's outputting a memory error with all bits bad at the beginning of memory, which is highly unlikely to be true. However, this does show that the ULAs are good, the CPU is running and the data bus transceiver is working.

Giving a memory error with all bits bad, with a working transceiver points to a RAM address multiplexer(74LS157), either IC19 or IC20. With some experimentation on my test machine this morning I can replicate the person's issue by removing IC19.

Of course, there may be other issues with the machine but I'm guessing that IC19 is the problem stopping the machine from displaying anything.

[PhilC]

Well, it looks as though my Sinclair QL diagROM is coming in useful at last.

Someone on the QL forum has a machine which has a black screen when he turns it on. He's install my ROM and that's outputting a memory error with all bits bad at the beginning of memory, which is highly unlikely to be true. However, this does show that the ULAs are good, the CPU is running and the data bus transceiver is working.

Giving a memory error with all bits bad, with a working transceiver points to a RAM address multiplexer(74LS157), either IC19 or IC20. With some experimentation on my test machine this morning I can replicate the person's issue by removing IC19.

Of course, there may be other issues with the machine but I'm guessing that IC19 is the problem stopping the machine from displaying anything.

Nicely done Stephen, I'll be sure to try it if my QL ever dies :D

[stephen_usher]

Despite a heavy cold which just won't go away I've been making progress on the model railway building using 3D printed parts.

IMG_5008.jpeg

The office windows and doors are done as are the structures behind the waiting room doors and windows. A minor issue will need to be fixed there. I can't put the windows themselves on yet as it's too windy outside to spray the glue onto the frames so that the photographic gel will stick. From the weather forecast it's probably going to be a few days until it's going to be possible.

On the retro-computing front, it looks like I may have a new project on the way, an old computer recreation, so following @rubber_jonnie a bit. :-) I'll keep it a bit of a secret until the PCB has arrived and I can start.

[rubber_jonnie]

On the retro-computing front, it looks like I may have a new project on the way, an old computer recreation, so following @rubber_jonnie a bit. :-) I'll keep it a bit of a secret until the PCB has arrived and I can start.

Sounds splendid, hope you can get well soon to enjoy it :)

[HigashiJun]

Love it !

But take care of yourself.

[mrbombermillzy]

On the retro-computing front, it looks like I may have a new project on the way, an old computer recreation, so following @rubber_jonnie a bit. :-) I'll keep it a bit of a secret until the PCB has arrived and I can start.

All these 'secret projects' everyone has going on ATM. :roll: :lol:

Hope the cold goes soon Stephen.

[rubber_jonnie]

On the retro-computing front, it looks like I may have a new project on the way, an old computer recreation, so following @rubber_jonnie a bit. :-) I'll keep it a bit of a secret until the PCB has arrived and I can start.

All these 'secret projects' everyone has going on ATM. :roll: :lol:

Hope the cold goes soon Stephen.

Damn, I don't have a secret project!

I need to get one 😁

[stephen_usher]

I need to get one 😁

Hehehe!

Mine's only secret as I don't know if it's even going to arrive at the moment... though it should, but unknown when.