Search found 1182 matches

by Kazzie
Tue Apr 07, 2020 8:21 pm
Forum: off-topic
Topic: Which retro calculator is best?
Replies: 26
Views: 607

Re: Which retro calculator is best?

The red LED display TI-30 might win. Especially if you remember how slow it was for calculating trig functions. I picked up a TI-30 from a charity shop two decades or so ago, and enjoyed learning it's different syntax for entering calculations (as compared to the "Direct Algebraic Logic" on my EL-5...
by Kazzie
Tue Apr 07, 2020 8:10 pm
Forum: hardware
Topic: Vine Micros Master OS Overlay board
Replies: 2
Views: 61

Re: Vine Micros Master OS Overlay board

Here's what I've found on a quick digabout: The black wire is connected to pin 22 of three of the ROM sockets on the board (the three additional ones). Pin 22 is the chip enable pin. From the piggyback connector pictured, the other end of the black wire must connect to either pin 2 or pin 9 of a 14-...
by Kazzie
Tue Apr 07, 2020 11:23 am
Forum: general
Topic: Today I received.....
Replies: 5708
Views: 491957

Re: Today I received.....

tricky wrote:
Mon Apr 06, 2020 9:36 pm
I have the duratool but have been thinking of adding a "tank" and instant value like I saw on YouTube to give it a little more initial suction.
That sounds like a dodgy investment proposition! :lol:
by Kazzie
Tue Apr 07, 2020 7:43 am
Forum: hardware
Topic: Reserrecting my old A420/1
Replies: 7
Views: 262

Re: Reserrecting my old A420/1

What helped with me is switch it on after a moment switch it off and do that a couple of times. You can be lucky that the ST506 comes back to life. Hi Tim I tried that, but it is dead as a door nail, but all my floppies seem to be ok so, once the drive is replaced with a modern solid state device w...
by Kazzie
Tue Apr 07, 2020 5:16 am
Forum: hardware
Topic: HELP! A3000 dead
Replies: 13
Views: 257

Re: HELP! A3000 dead

I could be wrong, but I don't think the ROM checksum does use RAM. There are plenty of 32-bit registers in the ARM, so there's no reason for it to need to use RAM. Hoglet is correct here; the ROM checksum does not use the RAM. The self test code is very sensible in that regard; it does a few basic ...
by Kazzie
Mon Apr 06, 2020 7:01 pm
Forum: hardware
Topic: HELP! A3000 dead
Replies: 13
Views: 257

Re: HELP! A3000 dead

The routine for calculating a checksum of the ROM will make use of RAM, so a RAM fault could account for both of the first two items on the list. I would have expected the MEMC to continue generating a CAS signal even when it signals an ABORT to the ARM. Acorn literature of the time tends to be extr...
by Kazzie
Mon Apr 06, 2020 4:12 pm
Forum: hardware
Topic: Looking for 3D printing tips
Replies: 16
Views: 315

Re: Looking for 3D printing tips

Ooh, I worked on that one: my first job in Canada was working on their editorial system. It was … quite special. I don't think the Gage exists any more: I think it's now published out of HarperCollins, so might be edited in the same office I worked in near Glasgow. Well, that particular copy of the...
by Kazzie
Mon Apr 06, 2020 10:18 am
Forum: off-topic
Topic: Which retro calculator is best?
Replies: 26
Views: 607

Re: Which retro calculator is best?

Ooh, that's a nice British Thornton you've got there! (Says the guy with a box of slide rules on a shelf.) I went through High School with a Sharp EL-506R. It seems that the original EL-506 was released in 1980, so just outside the scope of this thread. I bought a TI-89 graphing calculator for Unive...
by Kazzie
Mon Apr 06, 2020 10:07 am
Forum: hardware
Topic: Looking for 3D printing tips
Replies: 16
Views: 315

Re: Looking for 3D printing tips

🇨🇦, please. Apologies! I actually wasn't assuming you were from overseas at all, a few people over here spell it that way as well. Normally it's obvious what they mean from the context, but this time it wasn't. Those Canadian spelling differences are interesting - I wasn't aware of them, even thoug...
by Kazzie
Mon Apr 06, 2020 9:52 am
Forum: hardware
Topic: HELP! A3000 dead
Replies: 13
Views: 257

Re: HELP! A3000 dead

I'm particularly concerned about the ABORT line being active on MEMC. The ARM datasheets describe the MEMC's abort output as follows: Processor Abort (CMOS level output) - Determines whether the current memory cycle will terminate abnormally. When asserted (high) MEMC has detected either an attempt...
by Kazzie
Mon Apr 06, 2020 5:38 am
Forum: acorn atom and system
Topic: Atom just acquired not working
Replies: 32
Views: 630

Re: Atom just acquired not working

Kazzie The logic probe is affordable but what would it tell me lacking any knowledge of electronics? I do have a good quality digital multi-meter so I will check the VCC and VEE for all the chips. John The digital multimeter can give very useful readings for voltages that are fixed, but it's of lim...
by Kazzie
Sun Apr 05, 2020 5:54 pm
Forum: acorn atom and system
Topic: Atom just acquired not working
Replies: 32
Views: 630

Re: Atom just acquired not working

I do not have Scope and friends who have one are to remote from me. I am one of those who are in self isolation so that option is not available. Another option would be a multimeter (continuity tests and DC voltage averages can be useful measurements in a pinch), or alternatively you could buy a lo...
by Kazzie
Sun Apr 05, 2020 5:30 pm
Forum: general
Topic: Wikipedia articles on Econet and DFS [citation needed]
Replies: 12
Views: 542

Re: Wikipedia articles on Econet and DFS [citation needed]

This is very interesting. Some of the limitations of DFS, like rather short filenames, 31 files per disc etc. feel like they really belong to a prior era. If DFS was ported quickly from the the Acorn System to fill a space that certainly explains that as well as the choice of 8271 which was old eve...
by Kazzie
Sun Apr 05, 2020 4:49 pm
Forum: hardware
Topic: HELP! A3000 dead
Replies: 13
Views: 257

Re: HELP! A3000 dead

Have you checked ROMCS and the address lines at the ROMs themselves?
by Kazzie
Sun Apr 05, 2020 2:18 pm
Forum: hardware
Topic: Any interest in an A310?
Replies: 2
Views: 138

Re: Any interest in an A310?

Agreed. The fact that your A310 is already upgraded to 4MB and cas a SCSI interface will also make it very appealing.
by Kazzie
Sun Apr 05, 2020 1:31 pm
Forum: upcoming and recent events & exhibitions
Topic: ABug Scotland (working title) Meeting 4th April 2.00pm
Replies: 9
Views: 455

Re: ABug Scotland (working title) Meeting 4th April 2.00pm

For those here that might be interested in joining, what does one need to do? I would welcome Kazzie as an Expert participant although form outside the title geography. For the avoidance of doubt, I asked the question for everybody else, to prompt Richard to add a few more details. I wasn't actuall...
by Kazzie
Thu Apr 02, 2020 4:08 am
Forum: off-topic
Topic: Which retro calculator is best?
Replies: 26
Views: 607

Re: Which retro calculator is best?

Yeah, pretty likely those slides were about A, or AS level, or even Further Maths. Definitely, material such as integration and solving equations involving surds is part of the A-level syllabus. The opening sentence of "students taking the statistics option" is also a giveaway; there's no such opti...
by Kazzie
Wed Apr 01, 2020 4:44 am
Forum: archive requests
Topic: The Magic Telephone (aka "The Magic Telephone Box")
Replies: 24
Views: 6039

Re: The Magic Telephone (aka "The Magic Telephone Box")

Dan O'C wrote:
Tue Mar 31, 2020 9:11 pm
Is this it?

http://www.flaxcottage.com/educational/ ... .asp?p=188

As in the part 2 of magic telephone?
No, I'm afraid that's part 1. :(
by Kazzie
Tue Mar 31, 2020 1:56 pm
Forum: introduce yourself
Topic: Hi from Dorset
Replies: 10
Views: 162

Re: Hi from Dorset

There are also two pieces of software that can be used to send files and/or disc images from a PC straight to the Beeb over a serial cable: UPURS and XFER. You can use them to write an ssd or dsd image from bbcmicro.net directly to a floppy disc with the Beeb. :) XFER is the older program, and uses ...
by Kazzie
Mon Mar 30, 2020 2:30 pm
Forum: introduce yourself
Topic: Hi from South Wales
Replies: 8
Views: 159

Re: Hi from South Wales

Here's a friendly wave from the other side of the Cambrian mountains. :)
by Kazzie
Sun Mar 29, 2020 2:54 pm
Forum: hardware
Topic: A3000 power on test check error
Replies: 47
Views: 1606

Re: A3000 power on test check error

Is that the same chip as used in the A4x0/1 series for on-board RAM expansion? Thanks Kazzie. Checked the service Manual http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manuals/Acorn_A4001R140SM.pdf They seem to have the same part number (0704.118) Right, now all I have to do is find my spare...
by Kazzie
Sat Mar 28, 2020 8:27 pm
Forum: hardware
Topic: A3000 power on test check error
Replies: 47
Views: 1606

Re: A3000 power on test check error

I assume this means my IC24 needs replacing? I found the Service Manual on line which states the part as IC DRAM 256Kx4 120n 20ZIP. Did a search but could not find any for sale. Does anyone know where I may find one? Is that the same chip as used in the A4x0/1 series for on-board RAM expansion? If ...
by Kazzie
Fri Mar 27, 2020 8:49 pm
Forum: hardware
Topic: Another loft refugee to be rescued!
Replies: 6
Views: 276

Re: Another loft refugee to be rescued!

If you don't want to go down pulling the keycap off, hammering away for a little longer could be an option. I've known stubborn keys to require a few hundred presses to get them working reliably again. The good thing is that they're built to take that kind of hammering. :)
by Kazzie
Thu Mar 26, 2020 11:52 am
Forum: general
Topic: Master spray job
Replies: 35
Views: 2043

Re: Master spray job

jms2 wrote:
Thu Mar 26, 2020 11:23 am
I do wonder whether CUB monitors were actually painted in this RAL colour actually, and that's where the false memory comes from.
Might it be influenced by the lighting used where you used Beebs in the days of yore?
by Kazzie
Thu Mar 26, 2020 8:15 am
Forum: introduce yourself
Topic: Greetings from Wiltshire
Replies: 11
Views: 374

Re: Greetings from Wiltshire

daveejhitchins wrote:
Thu Mar 26, 2020 7:43 am
4 Electrons =D>
Good point. Perhaps we should change Mark's username to Beryllium? ;)
by Kazzie
Thu Mar 26, 2020 5:12 am
Forum: introduce yourself
Topic: Greetings from Wiltshire
Replies: 11
Views: 374

Re: Greetings from Wiltshire

That's a nice home-made wire-wrap job on that Sideways RAM board in the Beeb. :)
by Kazzie
Wed Mar 25, 2020 4:32 am
Forum: hardware
Topic: BBC B long beep and (mostly) unresponsive keyboard
Replies: 7
Views: 286

Re: BBC B long beep and (mostly) unresponsive keyboard

Let us know how you get on. :)
by Kazzie
Tue Mar 24, 2020 5:33 am
Forum: hardware
Topic: BBC B long beep and (mostly) unresponsive keyboard
Replies: 7
Views: 286

Re: BBC B long beep and (mostly) unresponsive keyboard

Assuming the keyboard connector's fine... Both the sound chip (IC18) and keyboard connector are interfaced through the System VIA, IC3. You may have tried swapping that chip out already. If so, there's an associated chip nearby that could be to blame. IC32, a 74ls259, buffers several values out of t...
by Kazzie
Sun Mar 22, 2020 3:27 pm
Forum: upcoming and recent events & exhibitions
Topic: ABug Scotland (working title) Meeting 4th April 2.00pm
Replies: 9
Views: 455

Re: ABug Scotland (working title) Meeting 4th April 2.00pm

For those here that might be interested in joining, what does one need to do?
by Kazzie
Sat Mar 21, 2020 2:48 pm
Forum: hardware
Topic: BBC Master Compact - blank screen and beep
Replies: 18
Views: 494

Re: BBC Master Compact - blank screen and beep

Here's four possible approaches for you: :arrow: Those measurements with your logic probe indicate that the clock signal is good, but the lack of activity on the data lines suggests that the CPU has already stalled. If you probe the CPU's reset pin, and some of the address lines (say A0-A2), you can...