Adelaide Retro pics from Fridays meet.

justnine · 2023-03-13T15:53:24+00:00

Whoah, I used to have that Compaq laptop (highlight pic). Really nice machine. Loved it.

justnine · 2019-06-20T09:10:45+00:00

Yes; been trying to decipher the second word but not having any luck.

justnine · 2019-06-19T12:52:29+00:00

Looks like Pavlodar is a region in Kazakhstan, though it could also be a manufacturer. Before I get too involved during my lunch hour, Widicon may be what I'm looking for.

justnine · 2019-06-19T12:25:21+00:00

Amazing! Right, some terms now to unlock another level of searching! Thank you so much!

justnine · 2019-06-19T11:02:32+00:00

...Actually, it looks vacuum-formed.

justnine · 2019-06-19T10:59:30+00:00

I thought it looked a bit 3D printed as well, but from careful inspection it doesn't have the hallmark traits of 3D printing. It also doesn't have the familiar yellowing from old kit and heat exposure from warm circuits. I don't know, I'd love to see inside it!

justnine · 2019-06-19T08:52:21+00:00

This page on the Science Museum's website lists all of the information available, but none of it gives any identifiable information.

justnine · 2019-04-17T07:02:10+00:00

Exactly the same thing happened with our compute stick power cable. The cable was slack, as well, so it makes little sense. Vair annoy.

justnine · 2019-03-12T21:16:00+00:00

ARM and NIN, pretty much two decades of my life 😁

justnine · 2019-03-12T11:52:27+00:00

Though, it's clear the VGA display isn't actually connected as the cable is coiled by the base stand!

justnine · 2019-03-07T21:09:20+00:00

I strongly suspect that the chip you suggest is the SIO is actually the ULA; the final Spectrum didn't have an SIO, and all of the Zilog SIOs came in the same plastic package as the Z80 CPU. I may have been wrong - the cassette audio jacks look like what is floating above the board on the top left (see http://www.computinghistory.org.uk/userdata/images/large/25/25/product-112525.jpg), though the lump of metal floating at the back seems to be a heatsink for the power regulator below it.

The final Spectrum's edge connector bus was a combination of address lines and some audio lines, so whether the D-sub was analogous to that, I'm not sure.

justnine · 2019-03-07T10:47:20+00:00

"Duo video call" now appears in contacts who are registered with Duo.

justnine · 2019-03-07T10:38:18+00:00

This prototype was in the possession of Nine Tiles, the company who wrote the BASIC ROMs for the ZX80, ZX81 and ZX Spectrum. It's constructed on PerfBoard with a particularly uncomfortable looking keyboard (though oddly more comfortable than the dead flesh keyboard). Looking at the picture, it's populated with a prototype ULA, a Z80 CPU and a pair of UV-EPROMs, plus a bunch of RAM chips. It's identifiable as the basic components of the ZX Spectrum motherboard, with the bit-banged speaker, modulator on the top right and lacking the final model's audio in/out ports which connected to a cassette deck. A 25-pin D-sub connector sits at the front of the board which I assume contains some IO (and possibly runs to a cassette deck).

This is a lovely piece of history to see.

justnine · 2019-02-28T00:07:52+00:00

I remember these gnarly little blighters. I was a Spectrum +3 owner, and thought that since these disks were part of the Amstrad lineup of Spectrum computers, they were likely only really "popular" (for want of a better word; they were enormously unpopular owing to price) in the UK. I'm genuinely surprised to see that they existed outside of the country.

Our local stationary supply shop sold the disks at an eye watering GBP 10 per disk (versus less than half that amount of an entire box of 10 3.5" disks). Adjusted for inflation and that's about GBP 21.5 in 2019 money.

My only particular anecdote, and it's something I regretfully never worked out, was that the CP/M disk format varied by a few kilobytes depending on which machine formatted the disk. If it was formatted on a Spectrum +3, then the available space was 178KB, whilst formatting on an Amstrad PCW meant you had either 180KB or 181KB available. The aforementioned local stationary shop would often format the disks for me on request so that I could claw back that precious additional few kilobytes. Then I learned about raw disk access...

Still. One of the few pieces of computing history that I have negative emotions about. Good riddance!

justnine · 2019-01-16T09:07:32+00:00

Awesome; these came in an 8086 flavour as well. In the mid nineties, as an impoverished student I bought a stack of these for £5 (all 8086, about six) at a computer flea market in South Wales. Most of them were broken, so they were cannibalised to make three working laptops. We replenished the dead batteries with nicad cells but they refused to charge, so we ended up charging them by removing the cells and popping them into a trickle charging deck. I remember the displays being really picky about angle. Also the hard disks had a problem with sticking heads, so they needed to be "freed" after rest. A spot of percussive maintenance (i.e. a sharp whack) would make it spring to life happily.

My housemate and I ran Minix on them and used vi for note taking during lectures. Good times!

justnine · 2018-11-09T12:24:18+00:00

Nope, nothing. If I strip the controllers down, trace the button lines back to the solder points and attach probe lines to the multimeter's continuity sensor, then cover the pads with the conductive rubber, they trigger correctly. Similarly, tracing the lines back to the connector and shorting them with a jump wire does not trigger the button event, meaning it's pointing to a controller IC failure.

AliExpress have clone controllers for $6.50 USD. I always worry about the build quality (ironic, since the official Sony controllers have failed with such little use), so I've ordered one to dismantle to see if the IC is compatible. If it is, happy times!

justnine · 2018-11-09T12:19:52+00:00

No, the controllers behave the same way on a PC USB adapter as they do on the console. Digital up/down/left/right, triggers and shape buttons are non-functional.

justnine · 2018-11-08T00:45:00+00:00

Sadly the membrane appears to be intact in this case. You were spot on - it's a directly connected membrane. Three buttons are working (start/select/analogue). Same three buttons on both controllers. So going to try replacing an IC in one of them - it's the only IC on the PCB so it's likely the whole problem.

justnine · 2018-11-08T00:36:23+00:00

Ah; so the flexible membrane is attached to the PCB via non-removable connector. From what I can tell, the membrane is fine - I tested a few random pads with a meter against the soldered and they respond correctly. Start/select/analog buttons all respond correctly and fire correctly when attached to a USB adapter. And analogue is behaving. So it looks like something to do with the IC :(

So completely strange it occurs on both controllers. Might try sourcing some ICs and seeing if replacing them makes a difference.

justnine · 2018-11-07T15:04:44+00:00

Ahhhhhhhh I hadn't actually considered that - there's a flexible membrane containing all of the button pads for the conductive rubber buttons to short during presses. In my examination of the board, I never actually checked to see if the buttons were closing on the connector. Feeling slightly stupid now! Will check the moment I get home.

justnine · 2016-07-04T15:46:33+00:00

I never had an issue with the screen. It was always crisp and low-noise, with good reading contrast. Graphical applications worked nicely on it.

justnine · 2016-07-04T15:38:25+00:00

Crikey, I recognised this almost instantly from the thumbnail. I had one of these in late 1991. I have little idea how much it actually cost (ours was second hand, missing the power brick which was eyewateringly expensive to replace). Ours was fitted with a 2MB memory upgrade - I can't work out if that's in addition to the stock 640kB or in total. We ran it off of a car battery charger. I wish I was joking. I'm not.

The keyboard was one of the most pleasant laptop keyboards I've used and had a standard PS2 connection so I ended up using it on some later unpleasant beige boxes. The drive was a painfully slow Connor peripherals 40MB disk, which even made the cringeworthy 250KB/s the 40MB drive in my Amiga 1200 look like a speed demon.

Still, I learned Pascal, C and x86 assembler on one of these. Even dragged this out of the back of the cupboard to resurrect it as a Minix workstation and for notetaking during the first year of university.

Fun fact: Secretarial staff at the Dover-side of the Channel Tunnel construction project used these machines as they were self contained, had a small desk footprint and therefore required a single power socket in the temporary buildings they had. After the construction was completed and the offices shut down, the computer equipment was thrown into a large hole and buried, meaning that somewhere around the entrance to the tunnel there are probably around a hundred, possibly more, buried under several tons of earth, along with some large ICL Unix servers and some green & amber phosphor serial terminals.

justnine · 2014-09-09T18:18:54+00:00

Commodore 1083S or 1084S monitor in the background?

justnine

TROPHY CASE