Search found 202 matches

by mw0uzo
Wed Feb 15, 2017 9:52 pm
Forum: software: other
Topic: Bad Apple - 25fps video on the Beeb
Replies: 51
Views: 3875

Re: Bad Apple - 25fps video on the Beeb

Brilliant well done! =D> =D> =D>
by mw0uzo
Tue Feb 14, 2017 6:54 pm
Forum: hardware
Topic: Internal RPi/CoPro serial link Master
Replies: 8
Views: 882

Re: Internal RPi/CoPro serial link Master

Tips for using TERMINAL rom: Shift F1 - Bring up command prompt. MODE 0 : Use this mode *FX 210,1 : Disable sound, get rid of the annoying beeps every time a character that is misunderstood is received. *FX 210,0 : Enable sound *FX 4,1 - Disable cursor editing, or BBC won't send cursor keypresses to...
by mw0uzo
Tue Feb 14, 2017 12:07 am
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

Going through parts of the chip select decoding (urrrgh) IC22 providing gate to IC21 chip select generator for VIAs etc - OK /G from IC22 to IC39 pin 15 stuck high. /INTON, /ROMSEL, /VIDPROC stuck high Did several captures, they never activate. Does anyone know what /ROMSEL does? Maybe it goes low w...
by mw0uzo
Mon Feb 13, 2017 5:03 pm
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

Here you can see what happens with the MOS/BASIC rom in: 3 power ups - 3 different traces! b+rom0.JPG I don't recognise the pattern of SYNC here b+rom1.JPG Nor here, and no clock stretching from 1Mhz bus activity b+rom2.JPG This last capture is what I thought was ROM executing properly, at least ini...
by mw0uzo
Mon Feb 13, 2017 4:35 pm
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

Ok what it does is this testrom.JPG Then after a short while the CPU hangs completely with no SYNC, nothing. testrom2.JPG Tricky, does your test rom write to any of the Beeb's hardware registers, or does it launch immediately into copying RAM around, using the default mode that the display IC starts...
by mw0uzo
Mon Feb 13, 2017 3:53 pm
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

Handy drawing that! :D

I think what I'll do next is capture operation with tricky's ROM to see if it's executing continuously or hanging.
by mw0uzo
Mon Feb 13, 2017 3:44 pm
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

I forget the details about Tricky's test ROM. But keep in mind, the address decoding logic on the board decides where in the CPU memory map the ROM appears. So in the EPROM (assuming a 27128 / 27C128) chip is used, the code should start at ROM address 0000 and go all the way to the end (so that the...
by mw0uzo
Mon Feb 13, 2017 2:21 pm
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

- Main 16Mhz clock OK - 8,4,2,1 Mhz outputs from VidProc OK - /1E clock OK. No display output at all, no cursor etc. So VidProc not being initialised. - ROM ok in programmer, burned a new one just in case. No change. - Changed CPU and both VIAs, no change. Captured D7-D0 D2 seems to like being high,...
by mw0uzo
Sun Feb 12, 2017 12:13 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 109
Views: 9946

Re: PiTubeDirect signalconverter for BBC Micro

fordp wrote:I know how. I just find arrows showing the direction of data transfer more useful.


Ha must be a preferences thing, I cursed the max3232 converter board for having arrows instead of RX and TX.
by mw0uzo
Sat Feb 11, 2017 10:06 am
Forum: hardware
Topic: New (to me) A3000
Replies: 44
Views: 2021

Re: New (to me) A3000

=D> =D> =D>
Excellent!!! That really cleaned up well with the vinegar.
by mw0uzo
Fri Feb 10, 2017 7:58 pm
Forum: hardware
Topic: Internal RPi/CoPro serial link Master
Replies: 8
Views: 882

Re: Internal RPi/CoPro serial link Master

thats circularly brilliant! :) please, that is kjell's level shifter board isn't it? and, that max3232 board - thats just an arduino-type like this, yes? http://www.ebay.co.uk/itm/Mini-RS232-To-TTL-MAX3232-Converter-Adaptor-Module-Serial-Port-Board-ZD-/142182951755?hash=item211ac3ab4b:g:2mQAAOSwiDF...
by mw0uzo
Fri Feb 10, 2017 5:48 pm
Forum: hardware
Topic: Internal RPi/CoPro serial link Master
Replies: 8
Views: 882

Re: Internal RPi/CoPro serial link Master

SV204880.JPG
* Wires connected wrong here before I worked out why it wasn't working
SV204886.JPG
by mw0uzo
Fri Feb 10, 2017 5:46 pm
Forum: hardware
Topic: Internal RPi/CoPro serial link Master
Replies: 8
Views: 882

Re: Internal RPi/CoPro serial link Master

And the other ends of the patch wires to the serial port header like this. SV204884.JPG Then: *CONFIGURE BAUD 7 *CONFIGURE DATA 5 <Ctrl-BREAK> *TERMINAL MODE 0 <ENTER><ENTER> And on the PI Run sudo raspi-config and enable the serial terminal for login then sudo nano /boot/cmdline.txt and change the ...
by mw0uzo
Fri Feb 10, 2017 5:40 pm
Forum: hardware
Topic: Internal RPi/CoPro serial link Master
Replies: 8
Views: 882

Internal RPi/CoPro serial link Master

On the underside of the Master CoPro board, scratch off some enamel and solder on the MAX3232 converter board with two small pieces of wire SV204868.JPG Cut the track on the top side leading to the TX pin. SV204869.JPG Cut the track on the underside leading to the RX pin. SV204870.JPG Solder wires f...
by mw0uzo
Fri Feb 10, 2017 5:20 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 109
Views: 9946

Re: PiTubeDirect signalconverter for BBC Micro

Got the serial terminal working. It didn't work properly initially, I was scratching my head wondering why and wondering why the serial buffer chip was getting warm. GND and RX are the wrong way around on the silkscreen print - master version!
by mw0uzo
Thu Feb 09, 2017 3:55 pm
Forum: hardware
Topic: BBC B+ Repair log
Replies: 35
Views: 2162

Re: BBC B+ Repair log

It's groundhog day in mw0uzo's lab LOLolollolol
Replaced soldered in CPU, still broken.
Replaced 2 x soldered in VIAs, still broken :x
Looks like it's going to be a swine, out with the logic analyser etc again...
by mw0uzo
Wed Feb 08, 2017 10:18 pm
Forum: hardware
Topic: Help Master PBC
Replies: 3
Views: 379

Re: Help Master PBC

Got a PBC here if you need one, pm me.
by mw0uzo
Wed Feb 08, 2017 4:57 pm
Forum: hardware
Topic: Microvitec Cub 1431 repair
Replies: 9
Views: 805

Re: Microvitec Cub 1431 repair

Fixed. The problems were
Noisy/bad brightness pot.
Bad focus pot.
Switch cleaner on both and worked them for a minute, left to dry then reset.
by mw0uzo
Tue Feb 07, 2017 2:35 pm
Forum: hardware
Topic: Dead BBC Masters - ROM screwup leading to main system damage
Replies: 234
Views: 8816

Re: Dead BBC Masters - ROM screwup leading to main system damage

ok - interesting.
I swapped over the User and System VIAs, the machine booted and the TurboMMC was working.
I wonder why this is. I tried two VIAs in the user position with the same results. Then swapped and all was working... hmmmm
by mw0uzo
Tue Feb 07, 2017 1:26 pm
Forum: hardware
Topic: Dead BBC Masters - ROM screwup leading to main system damage
Replies: 234
Views: 8816

Re: Dead BBC Masters - ROM screwup leading to main system damage

haha, the story is not over yet! Some EPROMS arrived, I burned a few TurboMMC DFS roms and put one in the Master. But it didn't seem to work properly. The original user VIA still in the troublesome Master had died :shock: TurboMMC not working and printing did not work properly. Replaced the user VIA...
by mw0uzo
Mon Feb 06, 2017 9:52 am
Forum: hardware
Topic: Reviving a Master
Replies: 13
Views: 1104

Re: Reviving a Master

If you have to desolder the 6522, I'd recommend preheating the board with a hair dryer/hot air station and using good quality 2mm wide desoldering braid, surface mount rework flux and an iron at a hot temperature - i use my cheapo variable iron at 3/4 temperature - with a wide chisel bit. You'll hav...
by mw0uzo
Sun Feb 05, 2017 8:35 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 109
Views: 9946

Re: PiTubeDirect signalconverter for BBC Micro

Oh, right, that sounds like a good plan, or set of plans. Be aware of JGH's Tube-over-Serial protocol , that could be handy! (See also http://stardot.org.uk/forums/viewtopic.php?f=12&t=6141) Thanks for the extra info and for the heads up on the CoPro operating environment. Initially I was not a...
by mw0uzo
Sun Feb 05, 2017 5:19 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 109
Views: 9946

Re: PiTubeDirect signalconverter for BBC Micro

Access to the Pi (and the wifi, web, storage etc) would be a *TERMINAL away. So I can develop for Pi side and BBC side at the same keyboard/monitor. Just to be clear - you won't, I think, get anywhere trying to talk to the pi over serial when it's acting as a copro. You'd need to boot it into a ful...
by mw0uzo
Wed Feb 01, 2017 9:41 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 109
Views: 9946

Re: PiTubeDirect signalconverter for BBC Micro

Make sure you connect it with the BBC powered off, do not do what I did :( It would be tricky to hook up to the BBC and as the BBC Cannot multi-task easily it would not be that useful either. Oh no what happened? :( I've found a tiny MAX3232 converter board that will fix onto the CoPro pcb. That ca...
by mw0uzo
Wed Feb 01, 2017 11:25 am
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 109
Views: 9946

Re: PiTubeDirect signalconverter for BBC Micro

Got the boards, thanks sundbyk! Yes I did start having a look at removing the connector, i had the iron pretty hot and it wasn't going to be enough. Didn't try max temperature. I've got some rows of header pin sockets so what I think i'll do is trim and fit them to suit the Pi 1, and when a later Pi...
by mw0uzo
Mon Jan 30, 2017 7:51 pm
Forum: hardware
Topic: Microvitec Cub 1431 repair
Replies: 9
Views: 805

Re: Microvitec Cub 1431 repair

A few problems have occurred with the monitor so far
Brightness has gone funny - I'm hoping its a bad pot or something... Switches on bright but then fades and I have to turn it up at the back. Plus the brightness response isn't linear.
Monitor starts to lose focus after being on for a very long time.
by mw0uzo
Sat Jan 28, 2017 3:27 pm
Forum: hardware
Topic: Smoking !
Replies: 8
Views: 763

Re: Smoking !

Thanks for the advice. I guess I'm lucky that I've not heard a popping sound but if I intend to use my original beeb again I'll find someone local to replace the capacitors. My main intention was to go through my old discs (I have about 40 home made compilations) and see if there are any missing ga...
by mw0uzo
Fri Jan 27, 2017 4:38 pm
Forum: hardware
Topic: Microvitec Cub 1431 repair
Replies: 9
Views: 805

Re: Microvitec Cub 1431 repair

The 'tick' had gone from the monitor :)
Readjusted the RGB settings on the CRT neck and now its picture perfect =D>
by mw0uzo
Thu Jan 26, 2017 5:06 pm
Forum: hardware
Topic: Microvitec Cub 1431 repair
Replies: 9
Views: 805

Re: Microvitec Cub 1431 repair

Haha! It works! SV204825.JPG It seems the arcing, has been fixed, so far. I do get a curious 'tick' every 5 minutes or so though, hmmmm. For reason unknown, the vertical frame came back and I have a full picture. It's not centre, but it works! Focus OK. The green problem I thought had gone, but when...
by mw0uzo
Thu Jan 26, 2017 2:45 pm
Forum: hardware
Topic: Microvitec Cub 1431 repair
Replies: 9
Views: 805

Re: Microvitec Cub 1431 repair

I'm mobile, so don't have a schematic to hand, let alone the chance to look in mine, but if there are other electrolytic caps, it would be a good idea to renew those as well :wink: Mark Ok thanks, I never did find one for S3. Will probably need it for the vertical collapse problem, as the vertical ...