Search found 2284 matches

by jonb
Fri Nov 16, 2018 8:23 am
Forum: hardware
Topic: Spare Chips ?
Replies: 6
Views: 188

Re: Spare Chips ?

Aye well you and all your oil :( Bahh. Ive just bought my xmas dinner. Chicken Pot noodle. Bah humbug. Just dont get me started. Happy people and there good fortune. Go gie some cash to some poor bugger at needs it as some hae meat but cannae eat and some wud eat for want hid. Sorry, Google Transla...
by jonb
Thu Nov 15, 2018 12:43 pm
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

Today, the replacement 74LS00 turned up and my Micro UK101 is back working again. Couple of things to note that I'd forgotten: The BASIC only accepts upper case. Any lower case and you get "?SN Error". There is no rubout / backspace function, unless it is implemented by some other control character....
by jonb
Thu Nov 15, 2018 12:24 pm
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

So here's something interesting. In 1980, the UK101 would have cost you £219+VAT in kit form. Adjusting for inflation, that's about £897 in today's money, plus the VAT, of course so at today's extortionate 20% rate it comes out at £1076.40.

Yikes! No wonder my dad wouldn't get me one at the time.
by jonb
Thu Nov 15, 2018 7:11 am
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

Wouldn't really be a UK101 though, would it?
by jonb
Wed Nov 14, 2018 12:26 pm
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

:lol:

Good one VP!
by jonb
Tue Nov 13, 2018 6:08 pm
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

Your board is different; you can tell because the ICs are oriented differently. Steve sent me his design files, so I can see he has captured the schematics in KiCad himself. Maybe this eBay fellow copied it - I hope he got Grant's permission. BTW, Steve told me he hadn't got the board fabricated so ...
by jonb
Tue Nov 13, 2018 8:40 am
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

Hi Marcus Not for the faint-hearted? You can say that again. I was soldering it on Mother's Day 2011 and Mrs JonB wasn't impressed. IMG_5020.jpg IMG_5021.jpg Is there a more up to date version I could slot in? When I originally built it, I started a thread on 6502.org here: http://forum.6502.org/vie...
by jonb
Mon Nov 12, 2018 7:03 am
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

That's not bad..

Take a look at his other items. Those fully populated C64 boards look very good value for money.
by jonb
Sun Nov 11, 2018 9:50 pm
Forum: other vintage computer hardware, software and games
Topic: Micro UK101
Replies: 17
Views: 408

Re: Micro UK101

Nice one! Where did you get the board from? I built it using tripad Veroboard and point to point prototyping wire. The 8k BASIC is really old and still has the garbage collection bug. It's very satisfying to build one of these - although mine had an odd problem with the clock that prevented it worki...
by jonb
Thu Nov 08, 2018 1:43 pm
Forum: other vintage computer hardware, software and games
Topic: Fun with a PIC clock circuit
Replies: 8
Views: 111

Re: Fun with a PIC clock circuit

OK, the clock is not the problem. Red herrings. Let me remind you that this is on an 8080-ICE board I've re-engineered from a design by Bob Grieb. Turns out the PIC wasn't programmed correctly. I should have known. What I did was to try the PIC from my Z80-ICE (known working) in the 8080 ICE board, ...
by jonb
Thu Nov 08, 2018 11:47 am
Forum: other vintage computer hardware, software and games
Topic: Fun with a PIC clock circuit
Replies: 8
Views: 111

Re: Fun with a PIC clock circuit

PS you do know that oscillator design is considered to be one of the “black arts” of electronics? Yes, it's not the first time I've struggled with an oscillator circuit. When I built a UK101 from Grant Searle's web site I couldn't get its clock going either. Most of your check list points cannot be...
by jonb
Thu Nov 08, 2018 10:45 am
Forum: other vintage computer hardware, software and games
Topic: Fun with a PIC clock circuit
Replies: 8
Views: 111

Re: Fun with a PIC clock circuit

The other thing is that when I tested the (working) Z80 ICE with an external PSU, I couldn't see its clock ticking either (using a frequency counter), so I am wondering if I am barking up the wrong tree...
by jonb
Thu Nov 08, 2018 10:44 am
Forum: other vintage computer hardware, software and games
Topic: Fun with a PIC clock circuit
Replies: 8
Views: 111

Re: Fun with a PIC clock circuit

I also have one of Bob's Z80 ICE devices here, and the PIC's crystal clock is laid out symmetrically:

IMG_5006.jpg
Component side
InkedIMG_5007_LI.jpg
Solder side

You can see on the solder side the two capacitors (marked C) and the crystal (marked X); the tracks are perfectly symmetrical.
by jonb
Thu Nov 08, 2018 10:29 am
Forum: other vintage computer hardware, software and games
Topic: Fun with a PIC clock circuit
Replies: 8
Views: 111

Fun with a PIC clock circuit

Eh up Continuing my MDS repair odyssey, I'm now building an 8080-ICE which is a replica of the Tauntek ICE made by Bob Grieb. I'm having some problems getting the PIC clock to "tick". The PIC CLK circuit looks like this: PIC CLK schematic.jpg On the board it is laid out thus: PIC CLK layout.jpg Elec...
by jonb
Wed Nov 07, 2018 3:33 pm
Forum: other vintage computer hardware, software and games
Topic: Dragon 32 or Amstrad CPC 464
Replies: 24
Views: 340

Re: Dragon 32 or Amstrad CPC 464

Try this: https://www.ebay.co.uk/itm/253964720770 If you're near Bury St Edmunds as it is collection only, but it has joysticks, games and a monitor (which has the built in power supply) and you can see it working. Also, see here for some useful advice: http://www.cpcwiki.eu/index.php/Amstrad_CPC_Bu...
by jonb
Wed Nov 07, 2018 3:17 pm
Forum: other vintage computer hardware, software and games
Topic: Dragon 32 or Amstrad CPC 464
Replies: 24
Views: 340

Re: Dragon 32 or Amstrad CPC 464

The Dragon 32 used a Motorola 6809 processor (IIRC) and a very old video chip (old for the time, same as in the Atom I believe). As a result, it looks very primitive on screen. Software is hard to find. There wasn't that much for it in the first place (I remember this as I used to sell them), and wh...
by jonb
Tue Nov 06, 2018 9:05 pm
Forum: off-topic
Topic: Oscilloscope recommendations
Replies: 29
Views: 2809

Re: Oscilloscope recommendations

george.h wrote:
Mon Aug 24, 2015 6:02 pm
Apologies for resurrecting an old'ish topic, but has anyone any practical feedback they could offer on the Rigol DS1054Z?
Yeah, buy one.
EDIT: Sod it! I've bought one!!! =P~ =P~ =P~

...see? :D
by jonb
Wed Oct 31, 2018 7:54 pm
Forum: other vintage computer hardware, software and games
Topic: Superbrain #2: The Board
Replies: 55
Views: 2273

Re: Superbrain #2: The Board

This: viewtopic.php?f=45&t=15873

At the moment I have built the 8080 ICE but it doesn't work.

Am verifying the connections against the schematic. I probably made a blunder on the board.
by jonb
Wed Oct 31, 2018 3:17 pm
Forum: other vintage computer hardware, software and games
Topic: Superbrain #2: The Board
Replies: 55
Views: 2273

Re: Superbrain #2: The Board

Final update on this board.

I've returned it to Alan8086 unrepaired. A shame, but as I have had it for over a year and still not fixed it we decided to call it a day.
by jonb
Tue Oct 30, 2018 2:30 pm
Forum: other vintage computer hardware, software and games
Topic: Superbrain #2: The Board
Replies: 55
Views: 2273

Re: Superbrain #2: The Board

I checked the gate and it appears to be acting properly. Hmmm. It's interesting that if I poke 00, FF or AA into memory, it comes up fine, but it failes a memory test: 01 02 04 08 10 20 40 80 all return 00 when poked into a location (at C000). This looks like faulty RAM, but I have a NEOLOCH RAM tes...
by jonb
Sun Oct 28, 2018 12:50 pm
Forum: other vintage computer hardware, software and games
Topic: Intel MDS processor board start up
Replies: 5
Views: 334

Re: Intel MDS processor board start up

Speaking of building special things, here's a reimplementation of the Tauntek 8080-ICE, which I'm going to need at some point. It's got a voltage selector onboard so that the newer 3.3v 9536XL as well as the very hard to get 5v part. IMG_1179.JPG Not tested yet - waiting for a PIC programmer - but I...
by jonb
Sun Oct 28, 2018 12:44 pm
Forum: other vintage computer hardware, software and games
Topic: Intel MDS processor board start up
Replies: 5
Views: 334

Re: Intel MDS processor board start up

I have determined that the ROMs aren't getting selected. Unfortunately, the ROM select signals are generated by a PROM. The IPB uses two of them, they are Intel D3601, a type of fusible link PROM, so it is necessary to know what is inside them before drawing up any sort of truth table. As my program...
by jonb
Fri Oct 26, 2018 10:43 am
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

It'd be really cool to have this on a sideways ROM, with read / write to / from disk or cassette.
by jonb
Thu Oct 25, 2018 4:17 pm
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

Nice one, JG!

You'll probably find the PET port is simpler as it has no funky hardware like the C64.
by jonb
Thu Oct 25, 2018 12:22 pm
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

I was pretty desperate for a workable vi implementation on the CP/M boxes, because it would facilitate on-machine development. ..and be pretty cool as well. I've got one now - S - but it has disadvantages as I explained above. Back to the drawing board, methinks, and I'll probably do it in Z80 assem...
by jonb
Thu Oct 25, 2018 11:53 am
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

At this point, I'd like to hear the OP's views on the matter... :)
by jonb
Thu Oct 25, 2018 11:45 am
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

I already tried that, in Z80 assembly code. I instrumented it under Linux to see where it was spending all its time, then targeted the functions that were identified. So the answer to your question, Ed, is "not likely". It needs to be re-done the way S does it, in my opinion. The effort required amo...
by jonb
Thu Oct 25, 2018 10:33 am
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

Processor speed can overcome it. STevie uses a double buffer to detect display changes and this is the underlying cause of the slowness. It is also not using terminal escape sequences other than CLEAR SCREEN and GOTO (X,Y), so it often does more screen refresh work than it needs to (especially when ...
by jonb
Thu Oct 25, 2018 6:46 am
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

@lardo: Yes but would need to be compiled for ARM of course. I run it on an FPGA implementation of a CP/M machine (Grant Searle's Multicomp) and it is acceptably quick. This has an emulated 25mHz Z80.

Running STevie on a Z80 at 4Mhz is painful.
by jonb
Thu Oct 25, 2018 6:38 am
Forum: programming
Topic: Compiling VI for the BBC
Replies: 15
Views: 366

Re: Compiling VI for the BBC

STevie needs a filename or it will print the error message you saw. It doesn't have an "unnamed file" mode live vi. The allocation error is most likely caused by the #define FILELENG in stevie.h. When STevie starts, it allocates FILELENG bytes using malloc to hold the content of the file being edite...