I ordered some circuit boards from PCBWay using MerlinKV’s PlusD Clone design (CC BY NC SA). Now I’ll need to find all the parts (and work out how to blow a GAL).
“Oh”, they said, “so that’s what you wanted a serial protocol mouse for!”
#SAMCoupé #Lemmings
MGT SamBus repair
Update! Thanks to Colin from Quazar for clearing up my disinformation and abject nonsense.
I removed the old crusty battery and replaced it with an equivalent.
I also removed the corroded power socket. Apparently it was never, from a strictly electrical point of view, “entirely safe”, and so the official power supply never materialised. The 3.5mm audio jack would toggle between internal and external power when the jack was inserted or removed. Safe enough so long as all the power is off!
A wire link in place of the socket ensures the power supplied by SAM can still propagate to the connected devices on the four expansion ports.
A good scrub to get rid of the grime and battery juice, and it’s all working properly again.
What about those flat-head screws though, eh? Those MGT boys sure were goofballs! The cases were sent to customers separately after the bare boards were issued. So the original owner (or someone else) may have used any old screws.
Phew! Sorry for all the mistakes!
Yum! This is the special sugar-frosted MGT SamBus. (a.k.a. The SAM Card Cage). It adds extra expansion ports, a real time clock, and special secret coating that will keep you full until lunchtime. #SAMCoupé
Good news, everyone. It’s mousin’ time!
Oh no! I’ve been working on a fun little ZX Spectrum project using Microdrives and serial networking. That’s the end for this cartridge though. 😬
Come out to the coast… we’ll get together, have a few laughs.
I was playing the SAM version of Prince of Persia for about 20 minutes before realising I was actually playing the demo! After looping around the same 6 screens a dozen times I managed to glitch through a gate and it turned into Frogger (well sort of)
Low voltage 🔋🧲
High voltage ⚠️
I noticed my SAM was prone to tape-loading errors, and particularly when the cable gets jostled. Well that was because the socket was cracked, so I replaced it with one harvested from a broken cassette recorder.
The user manual is a bit vague about this, but SAM actually uses a stereo socket although only the ring (normally the right channel in stereo audio) is used for both input and output. The tip is not connected to anything. The idea is you would leave the SAM end alone and only swap the cable between the cassette recorder’s MIC or EAR socket depending on whether you were SAVEing or LOADing.
The replacement socket is an old-school mono design but it makes a rock solid connection so loading is now much more reliable.
Most SAM software is on disk of course, but quite a few demos were put out on Spectrum magazine cover tapes (and originally the machine came with a demo tape from MGT). I don’t have any official SAM tapes, but it works well with the TZXDuino digital tape player that I use for Spectrum software. I do have a few of those magazine cover tapes though and they also load really reliably now.
And, of course, SAM can emulate a 48K Spectrum so it’s possible to load those via tape (or TZX file) as well.
I’d been hesitant to take a soldering iron to my SAM Coupé, despite its display output suffering badly from reflection (i.e. ghosting) artefacts. But the recommended fix (by Quazar, see SAM Revival #1) is so simple I couldn’t put it off any longer! A huge improvement. 🧑🔧👻
“Cobbled together” from some “spare¹ parts”—here’s my new ZX Spectrum +3 with a custom² Perspex™ sandwich³ style case, and external(ised) keyboard and floppy⁴ drive. 😁
- eBay boneyard
- “designed” and hand-drilled by me
- static electricity death trap
- Gotek floppy emulator
It’s not Retr0brite, it’s SAMbathing.
Meanwhile, in the laboratory: floppy head alignment issues, some Olympic-level desoldering, a disk controller transplant, and a hasty Shugart-to-Citizen bodge-it, but eventually… Pang! ✌️🎈
💾 #SAMCoupé
📚 Computer Projects for Railway Modellers by Roger Amos and Martin Cock, with program listings for Sinclair ZX Spectrum and BBC Microcomputer (Model B)!
Beta BASIC 4.0 (128K only)
spectrumcomputing.co.uk/entry/795…
#zxspectrum
I’m very happy to say my redesign of the Spectrum Computing logo to celebrate the Spectrum’s 40th Anniversary is now live! #zxspectrum
I’ve got some time to kill while my new Xbox game is Smart Delivering, so I’m just going to upgrade this here 3B’s DC–DC circuit while we wait. #zxspectrum #loadingtimes
Moc-moc-a-moc-me-do!
Death’s Door is really good!
I think I might head into town. There’s an article about TELETEXT in the latest MagPi magazine! ❤️💚💛💙
Lemmings! On a ZX Spectrum!! With a mouse!!!
(It’s absolutely fine on keyboard, but this is the way it was meant to be played).
And speaking of Text Adventuring, here’s the CRASH Annual 2022 exclusive* game Saboteur: Deep Cover. A text adventure with real time combat??
KICK, PUNCH, it’s all in the mind! 🥷👊🤖🐆
(*Kickstarter only, but it’s out on Cronosoft later.)
I’m currently reading: Twilight Inventory by Gareth Pitchford 📚 A collection of 1990s reviews/articles of “forgotten 8-bit adventure games”, it recounts the spirit of the latter years of the DIY-gaming cambrian-explosion brought about by tools The Quill and G.A.C.
