Curses. After owning my Apple eMate 300 for 20-odd years I’ve finally found out why it won’t power up 💥 Time to find out what THIS part was before someone put too many electrons up it. Might be able to resurrect this beastie if the regulator was sacrificial and nowt else got zapped.

Woop! Battery bombed A3000 has gone from this to this to this. SO CLOSE now, just need an MB81C4256A 120ns ZIP20 RAM chip.

The latest Dino inhabitant is currently catching some rays. Impressively the whole setup is the same brown colour including the printer. It’s an M0001 ‘Fat Mac’ and it’s missing a CTRL key. Thankfully the battery hasn’t leaked outside its containment so the only thing to worry about is the RIFA.

😮 This means it's 10 years since I failed to get my 40th anniversary 6502 Badge running. It's in a drawer somewere, perhaps I should dig it out.

Y!kes! OK, if I don't fix the A3000 (Acorn not Amiga) that's currently on the bench it'll have to be parked while I run around finding stuff.

#Sharptember you say? Here’s an odd MZ700 I picked up the other week. It has what looks like an expansion slot connector and a power take off for… something. Manufacturer is “P.D.Systems Limited” in Surrey who may have been into process control, @sharpworks.bsky.social any idea?

A3000 update! One (1) vinegar bath later, a trip through the dishwasher (no detergent), IPA spray and dry in the sun and it's probably as good as it's going to get. Broken traces on the ROM lines repaired (2), ROM sockets replaced (4), bobbly capacitor replaced. Now where's my compatible monitor...

I only do old stuff, despite what happens in $DAYJOB. Can someone help Kitty?

Tis a nice day for drying motherboards and sunbrighting orange keyboards that very much should not be orange.

I'll be there! With what I don't yet know, but details schmetails. Come anyway 😁

Talking of retro shenanigans, one of the things I picked up last week was an Archimedes A3000, to replace the one I foolishly gave away 15 years ago. As usual with these machines it had been battery bombed, but not in a BAD way so a good dose of vinegar and a trip through the dishwasher will help.

Back to retro shenanigans this week, folks. It would appear that I spent most of August building the new workshop which will NOT have old machines in it. I promised Mrs Dinosaurs this 😇 Apart from these 3 monster DEC monitors which came out of the old shed. Obvs.

The Macintosh PowerBook G3 DuoWide was the ultimate writing-free distraction machine.

must... resist... reposting.

I only wanted to build a new workshop shed, not get chomped! #3DMonsterShed

Unsurprisingly, I have this book so it’s going to be fun reading the errata later to see what myths I’m still talking about that are wrong.

Apologies for lack of posts. After the Laser 200 fun the other week I've had a slightly more 'hardware' based project on the go - old shed demolition and sorting out the base for the new Megashed - my proper workshop for wood projects. I was fed up dragging the old B&D Workmate out of the garage :D

I will say the emergence of AI "art" and its constant use has made me value and appreciate the work of actual artists all the more. Art should contain something of the soul of the artist and I don't think you can inject that by saying "make me a video of a pretty lady singing about horses".

I thought I'd see if I can simplify loading via a cassette head. 'Nailed' it first go. 😂

The Gosh Wonderful ZX Spectrum ROM V1.40 is available for download along with a useful BASIC program “peeker” that I use to peek under the hood. It uses 3 routines by Steve Vickers written for other Z80 computers back in the 80s. They achieve total accuracy. speccy4ever.speccy.org/_CMS.htm

Those 1N4148 transistors eh, tricky blighters.

This is a very fine thing to see, working Torch Triple X workstations are very few and far between.

So. Laser 200 16k RAM pack, the whole reason I got this machine out in the first place. Bought as ‘new, boxed.’ Box is a little foxed which is fine given its age, but look at this! Factory sealed. Seems a shame to open it, but how will I know if it works if I don’t?

Argh! Argh! Bloody Laser 200 🤬 Perhaps the 2364-2764 conversion needs an extra step added to it, or it was already there and I missed it. I accidentally discovered eprom pin 27 (/PGM) wasn’t tied high as it should be. One bodge wire later and dead test springs to life 😳😲😆

Having a final stab at the Laser 200 after discovering that if I use a 28C64 EEPROM it gets overwritten, so something is making it scribble over 0x0000 upwards. Back to EPROMs, with a VRAM test program on a 2764A. This is the /CE line. I don’t think I’ve seen a regular pattern like this before.

Any z80 assembler types about? My cursed Vtech Laser 200 is continuing to be cursed, but I think I know what it’s doing. Trouble is, I don’t understand why.

Waiting for EPROMs to get UV blasted… Let’s make another Magic Brush™️ Bristles might not be long enough, that’s what I get for using haste. But we’ll see. Its first job is on the Laser 200 to track down what clobbers D6 on a write operation resulting in it being held low.

Look at this Lisa reproduction front panel. LOOK AT IT. I've a sudden need for £300 + shipping 😍 And then a scrap Lisa case so I can steal the back panel and top for my Mac XL, but that's a long time burner project. I've only had that machine 20-odd years so no hurry.

FAST20 eh? Must put this in my DEC Alpha DS10 next week, see if it boots.

This is fun, it's a history of a game written at Dartmouth College, the home of Dartmouth BASIC. It's called POTSHOT and it uses a teletype for input and a plotter for output.

If there are people with deeper knowledge of the QL chipset or anyone who would like to chip in with the collaborative project then that would be very welcome. Hopefully this could become a definitive diagnostic tool for the QL, in the same way as DiagROM on the Amiga.

🤬, but also 🎉 and 🥳 If anyone remembers @b3ta.com ‘Buffy’s Swearing Keyboard’ (it’s still out there) go to it and press ‘F’ then ‘Y’ Remember I couldn’t get my CST Thor to play nice before and during RetroFest? I thought RAM was at fault. This is what ICE looked like.

Morning retro fiends. What's the most cost-effective way to get hold of 2 or 3 copies of Windows Server 2019 and SQL 2016? Don't say 'cloud', this is a shoestring operation. It has to be windows and SQL too, unfortunately, so no point offering alternatives. Home lab let's GO.

15 years ago this month, I set up Tynemouth Software. So all this month, there is 15% off everything at my Tindie store. www.tindie.com/stores/tynem...

Commodore 128DD

Working away, heard a PING and a thud from the workshop end of the office. ‘What the hells was THAT?’ It was my WD40 lithium grease committing cani kiri. It’s not supposed to be swollen like that is it. Time to put the other aerosols on the floor.

Scratched a very long term itch today and finally got my paws on a Commodore 128D. Suddenly at Bring’n’Byte today I was briefly very popular while I took it to the car 😆 This one has JiffyDOS on board (at the cost of tape support) and is in fantastic condition. It also has a SCART cable, soo…

And there we go. A happy Compaq Prolinea 4/25s running Windows 3.1. I’ve not pictured the monitor because it’s not a compaq original but an NEC Multisync which will be more than useful in the future.

CRUST UPDATE! The battery-bombed Compaq Prolinea 4/25s board had a little sit in the dishwasher last night and it’s cleaned up a LOT. Bit more going over with the toothbrush and IPA this morning and all I have left is a bit of crud between the legs of one VLSI chip.

Crust update. CRUSTY. Might have to be the dishwasher for this one.

A quick Crust Update before work. Some green spots. Screw holding the board in snapped clean off but no components look to be obviously missing. Vinegar bath later. Underside is fine. Multilayer board though.

Picked up this Compaq Prolinea 4/25s from a mate on the way down to RetroFest. It used to be his Dad’s and has a somewhat colourful past. I remembered reading about the batteries in these things so set about it with the torx t15. @morefunmakingit.bsky.social look away now 😆

I'm not old, YOU'RE old.

House is too hot, so I shall head workshop-wards to stare at the Laser 200 whilst using brainpower to attempt to make it show me its secrets into why D6 gets flattened. Then give up on it for the day and move onto replacing the awful white sockets on the CBM4040 floppy drive board 😆

Laser news! There isn’t any really, but sampling the dead test ROM reads at the CPU, clocking on /RD shows the code is being read correctly. Clock using /WR and I can see that the VRAM writing is correct at the CPU. So somewhere between CPU and VRAM (a distance of ~4cm) the signals get mashed 🧐

The cursed Laser200 saga continues. Last night I did the ‘LED current’ continuity test on all address and data lines up to and including the 6847 and everything passed. Nothing pulling low, no dead spots and no shorts. I did the VRAM enable, RAM write, control lines. All good. WT actual F.

W00t! 🥳 Thanks to @thevintnerd.bsky.social for being my 1000th follower 🍻 Next stop, 1024?

This, and never forget Tulips.

Bonnet UP 😆

Temporarily back on the Laser200 now that I’ve got the milliamp-tester going. ROM side is all good. Display side however is HAUNTED. Pictured is the display chip, VRAM and the LS245 buffer that controls access to the video side. The red line is the path of D0 according to the schematics. /2