stardot.org.uk

How often do do you guys find the CRT controller (IC2) failing? The 6845 CRTC chips are fairly reliable. I'm surprised you've had so many fail. Are they all the same make/type? Did all these Beebs come from the same place? Get used with the same CRT monitor maybe? Although there's other circuitry b...

So although there are many times good points in this thread, I have a few thoughts to add. Everything in a computer can be broken down to simple logical steps. Humans don't normally realise it, but our own decision making process is also a series of small steps. It's just that like everything else w...

See also this thread Testing the Beebs User Port

Mark

Use a turned pin socket

Mark

Thanks

Mark

I presume you mean the coloured "paint" that has been applied over the top of the machine screw and on the sides of it. I normally use a thin flat bladed screwdriver to chip it away. Then once most of it is off, it's normally possible to get a Philips (size PH2) bit / screwdriver ( not a pozi drive ...

Water is a solvent. IPA is a solvent. Different "dirt" dissolves in different solvents... See this Wikipedia article.
So probably you need both! Start with the distilled water and unscented ordinary soap, wash with distilled water, then after dry, clean with IPA

Mark

I prefer chisel tips. On my soldering irons, I use a small one for use on SMD and small through hole pads (1mm). A medium size for general work (2.3mm 3mm), and a 4mm or 5mm where there is a lot of copper or metal that needs heating up. The larger tip is good for soldering/desoldering things like th...

Elminster wrote: ↑

Thu Jun 21, 2018 11:09 am

Shame was looking forward to the jumping electrons

Cue me banging the table while watching an Elk jump along it

Mark

Mine has arrived - has been built and is now waiting for connectors from RS . . . Cable will have to be in two pieces, but not an issue! Do you have extra excited protons and electrons (not Acorn) that are going to jump between the two bits of cable? I think he means that he is going to use two bit...

Oh yeah, those STFM mouse / joystick connectors under the keyboard. What a poor design. From what I can see they used to be where the disc drive ended up being put when they started fitting them internally. Shame they didn’t put a but more effort into finding a better home for them. The original At...

Yep, nobody on an iOS device would be able to see the flash versions, even if the https thing was resolved. Um, that's not true. I actually composed that post on an Apple iPad mini2 running Safari on iOS 10. Only the second embedded video does not work (expected as it's link is http not https). Scr...

An Atari 520STFM! Also the mouse, leads and some games. Is there anything I need to check before switching this on? No sources of magic smoke etc.? Magic smoke, not normally, no. Typical faults are:- Faulty PSU on/off switch, non-functional or crackles when operated (either clean the contacts or re...

So there is no form that works for everyone

Mark

For use on retro / old electronics, or for building your own projects that are not for commercial sale, use 0.7mm /22 swg 60/40 tin/lead solder with cored rosin-activated flux. If you are in the U.K. this solder from Rapid is good stuff. Multicore is a brand name that is also trusted. Tip temperatur...

This is where the improved draft facility comes in helpful. As now it is a lot easier to save your draft post. Then go do something else. Then come back and proof read it with a clearer (hopefully) mind. Then post it. Still not going to get every typo etc. But at least it's an additional tool to hel...

‪Embedding YouTube videos‬ Yeah, I noticed a problem with you tube videos. Was on my list of things to investigate further, but had not got around to it... Now (after update) this works: https://www.youtube.com/watch?v=6HLX2weZfkA [flash=425,344]https://www.youtube.com/watch?v=6HLX2weZfkA[/flash] W...

When Amstrad moved all manufacturing for the Spectrum to the Far East with Orion (who did the CPC, PCW and would be doing the soon to be launched PC's), Sugar threw the Timex factory the bone of assembling his DMP2000 printers. By the way, do you know who Amstrad used to assemble the U.K. made vers...

I presume the keyboard fits okay when EPROMs are installed all along the bottom row?

If so, nice design

And a nice find

Mark

Just so you are all aware, only moderators and administrators get the box where a reason can be entered when editing a post. So my recommendation is for members to add a line similar to this at the bottom of their post: Edited due to <reason> You can of course expand on this if you wish. However, if...

OK - you can choose a theme, or style, in the UCP that only shows you the edit line when someone's entered a reason for their edit: new-board-style.png Just so you are all aware, only moderators and administrators get the box where a reason can be entered when editing a post. So my recommendation i...

This forum isn't overrun with trolls The moderator and admin team do their best to keep the forums neat and tidy, so that when the occasional bit of trouble breaks out, it is cleaned up quickly. We are of course helped by members reporting any misbehaviour. So thank you to those members who have ta...

Don't think so...

Mark

I posted about using a light bulb in this post. It includes a diagram

Mark

When you say you checked that IC14 (74LS245 data transceiver), do you mean you tested the chip from the faulty machine in a known good machine AND tried a known good 74LS245 in the faulty machine?

Mark

If you have, or have access to an EPROM programmer, you can program Tricky's test 'ROM', then remove all ROM chips (including the OS ROM) and put the test ROM in the OS ROM socket. This should then show a picture if most of the rest of the 'core' system is functional. Tricky's test ROM does not need...

I guess one persons junk is another’s treasure, certain people in my household think any computer with less than 32 bits is junk. :) Computers with less than 32 bits are a bit rare. A ZX80 has 1024 bits and that's just the RAM... :lol: Mark Don't you mean 8192 bits of RAM? Err, yeah :lol: Been thin...

Click this link to take you to the poll...

Mark

Well done

I'm glad you got the 3.5" drive working.

Mark

On the 'Last edited by' footers, showing a count of edits will discourage me from fixing minor typos. I share the view that a short 'grace period' during which edits can be made invisibly should be allowed, if the forum software is capable of that. That might be a good compromise solution. But I ge...