Search found 153 matches

by johnkenyon
Fri Jul 13, 2018 5:00 pm
Forum: hardware
Topic: Cheap web-modem for the beeb/master (and arc if ya like!)
Replies: 103
Views: 3300

Re: Cheap web-modem for the beeb/master (and arc if ya like!)

OK, I've been keeping this one to myself for too long. I've posted an annotated disassembly of the Commstar 1.40 ROM at https://stardot.org.uk/forums/viewtopic.php?f=32&t=15377 If someone wants to provide me with the strings you need to send, I'm willing to either hack together a version which will ...
by johnkenyon
Fri Jul 13, 2018 4:51 pm
Forum: archive submissions
Topic: Commstar 1.40 disassembly
Replies: 0
Views: 63

Commstar 1.40 disassembly

Here's my annotated disassembly of Commstar 1.40 Note that it's written to be assembled using the xa 6502/RC65C02/68516 cross-assembler. For the uninitiated, this means: 1) $FF not &FF for hex 2) % indicates binary (used once) 3) ROR replaces ROR A, ROL replaces ROL A, and ASL replaces ASL A To asse...
by johnkenyon
Fri Jul 13, 2018 4:31 pm
Forum: hardware
Topic: Cheap web-modem for the beeb/master (and arc if ya like!)
Replies: 103
Views: 3300

Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Use commstar version 1.4. Once connected change from terminal to viewdata mode and ensure you press I and change the speeds back to 2400 before pressing C to enter chat mode again (ie connect to the modem). Commstar 2 won't work. Why don't you patch Commstar so that it starts in 2400 baud mode for ...
by johnkenyon
Thu Jun 28, 2018 10:57 pm
Forum: hardware
Topic: bbc b version finding
Replies: 3
Views: 170

Re: bbc b version finding

Note that the board issue does not tell you if it's a model A or a model B. Mark The absence of most interface connectors on the back (beyond cassette, RGB, video and RF) is usually a good indicator of a Model A, as is a missing user VIA+all underside IDC connectors. The absence of an Econet connec...
by johnkenyon
Mon Jun 18, 2018 11:33 am
Forum: hardware
Topic: Master PSU repair - not going well
Replies: 14
Views: 473

Re: Master PSU repair - not going well

If you are dealing with a short and want to probe around with the supply connected and without fuses popping, then use a lightbulb current limiter aka "the light bulb in series with load". Take one mains socket (preferably switched), a batten lightbulb holder, a length of 3 core mains flex and a plu...
by johnkenyon
Fri Jun 08, 2018 6:19 pm
Forum: hardware
Topic: Cassette player maintenance
Replies: 14
Views: 284

Re: Cassette player maintenance

Many years ago I worked for a company which, amongst other things used to service cassette player modules used in TOA BA-410 background music systems. These had 1 to 4 tape modules in a 19" case, and they played crappy background music in posh food pubs that didn't want a jukebox back in the 1980s. ...
by johnkenyon
Fri Jun 08, 2018 9:17 am
Forum: hardware
Topic: Early BBC Micro's (ICL)
Replies: 9
Views: 583

Re: Early BBC Micro's (ICL)

Here's my issue 2 model A, Cleartone manufactured, serial 100403 and all chips socketted which is very nice :) It's in great condition, so I don't want to modify (other than easily reversible) but it is rather limited without any ports...! I'm currently working up a reliable and reversible fitment ...
by johnkenyon
Thu Jun 07, 2018 3:38 pm
Forum: hardware
Topic: ECONET WOES
Replies: 70
Views: 3216

Re: ECONET WOES

Thanks John, means nothing to me though, I don’t do networks - I was just trying to help Darren with the question... :lol: One point of clarification, you said OSWORD &14 but the RTC call RAMagic supports is OSWORD 14 (decimal) or &0E. Maybe you meant &14 because that’s an NFS functions call but it...
by johnkenyon
Thu Jun 07, 2018 2:01 pm
Forum: hardware
Topic: ECONET WOES
Replies: 70
Views: 3216

Re: ECONET WOES

I could be completely wrong here but I don't think you can 'remotely read' the RTC dongle from a station, not a lot (as I have understood anyway) is known about it really. Darren doesn’t have a User Port RTC dongle, he has one of my RAMagic units which, amongst other things, includes a sideways rom...
by johnkenyon
Mon Jun 04, 2018 4:14 pm
Forum: hardware
Topic: Cheap web-modem for the beeb/master (and arc if ya like!)
Replies: 103
Views: 3300

Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Just a thought of mine will look at this weekend unless anyone else has? Just pure laziness but has anyone moded the commstar Rom image to default the send and receive and parity options to N81 9600 ? Just saves the time! I’ve moded Daniels Sketch to add a ATMYFI command that adds in my ssid etc an...
by johnkenyon
Tue May 22, 2018 9:00 am
Forum: wanted
Topic: Wanted Prestel Adapter
Replies: 7
Views: 422

Re: Wanted Prestel Adapter

That is a very kind offer, I have sent a message to John Kenyon in the hope of purchasing his, however, if for any reason that doesn't work out, I may take you up on your offer. I am particularly interested in the signalling that occurs on the RTS/CTS lines for dialling and call set up etc. The Aco...
by johnkenyon
Sun May 20, 2018 11:39 am
Forum: wanted
Topic: Wanted Prestel Adapter
Replies: 7
Views: 422

Re: Wanted Prestel Adapter

I have one - PM me with an offer (letting me know your location), noting that I won't be able to ship it for at least a fortnight.

/John
by johnkenyon
Thu May 03, 2018 11:16 pm
Forum: hardware
Topic: TEAC FD55V floppy phototransistor
Replies: 8
Views: 331

Re: TEAC FD55V floppy phototransistor

Any chance of some dimensions?
Outside diameter
Depth (base to start of dome)
Depth (base to tip of dome)
The electrical characteristics of a replacement device are probably secondary to how big the thing is.
/john
by johnkenyon
Thu May 03, 2018 8:26 pm
Forum: hardware
Topic: EPROM programmer
Replies: 18
Views: 904

Re: EPROM programmer

1024MAK wrote: [Some units don't prevent the UV light from escaping, so if light does leak out, don't look at the light!!!
But it's so beautiful...
(I'll get my coat)
by johnkenyon
Thu Apr 19, 2018 6:06 pm
Forum: hardware
Topic: SWRAM protection at power down
Replies: 8
Views: 600

Re: SWRAM protection at power down

The back in the day solution would be to copy the ATPL Sidewise board had a brown out protection circuit which prevented spurious RAM writes. A look at page 6 the battery backup installation manual may help: http://8bs.com/othrdnld/manuals/hardware/ATPLBatteryBackup_pdf.zip This did a pull down on o...
by johnkenyon
Thu Apr 12, 2018 11:12 pm
Forum: hardware
Topic: ECONET WOES
Replies: 70
Views: 3216

Re: ECONET WOES

Refer to the BBC B circuit diagram at http://mdfs.net/Info/Comp/BBC/Circuits/BBC/bbc.gif top left hand corner. Recheck the Econet installation see: https://www.beebmaster.co.uk/BeebShop/Downloads/BeebMaster%20Econet%20Upgrade%20Kit%20Fitting%20Instructions%20v2-5.pdf Double check all resistor values...
by johnkenyon
Sat Mar 31, 2018 2:14 pm
Forum: general
Topic: Today I received.....
Replies: 4684
Views: 316174

Re: Today I received.....

I was thinking about adding a voltage regulator to allow the clock to be safely powered from a Beeb auxiliary power port.... My Econet is only small at the moment, but it is growing, and my plan is to have separate 8bit and 32bit nets linked via a bridge :D You've already got a +5v supply on the BB...
by johnkenyon
Tue Mar 27, 2018 10:19 am
Forum: hardware
Topic: Capacitor size
Replies: 5
Views: 249

Re: Capacitor size

As a follow on, for radial capacitors (where the 2 leads stick out of the same end), if the pitch of the leads doesn't match the pitch on the board, the recommendation back in the day was that you keep the positive lead straight, and only bend the negative lead, on the basis that (1) you only bend o...
by johnkenyon
Mon Mar 12, 2018 9:52 am
Forum: wanted
Topic: WTD: NTSC Compatible TV
Replies: 8
Views: 490

Re: WTD: NTSC Compatible TV

Hi Guys, I have aquired a US NES for playing Tetris but need a compatible TV for it, preferably under 20". Had a look in the usual places but no joy. Anyone got any ideas or a set hanging around they would be happy to part with? thanks nOm If the NES has a composite video (yellow RCA/phono jack) ou...
by johnkenyon
Thu Mar 08, 2018 4:58 pm
Forum: hardware
Topic: 5.25" Drive Cleaning Kit
Replies: 27
Views: 1168

Re: 5.25" Drive Cleaning Kit

A google for "chamois cleaning swabs" (without the quotes) gives you a few options.

As for cleaning fluids, a bottle of IPA/iso-propyl alcohol/propan-2-ol from the local chemist was always my solvent of choice for tape heads back in the day.

/john
by johnkenyon
Sat Feb 24, 2018 2:11 am
Forum: archive submissions
Topic: Logotron Logo - Welsh version
Replies: 4
Views: 471

Logotron Logo - Welsh version

I've found this version of Logotron Logo - original label on the EPROM, looked like a match for http://mdfs.net/System/ROMs/Graphics/ACTLOGO100 However after running the image through the Unix/Linux "strings" command I see things like "CROESO I LOGO_C" and "rhif rhy uche" which Google translate tell...
by johnkenyon
Fri Feb 23, 2018 5:55 pm
Forum: archive submissions
Topic: Prestel and Teletext Adaptor ROMs
Replies: 2
Views: 414

Re: Prestel and Teletext Adaptor ROMs

Here's a zip file with the four images.

/John
by johnkenyon
Fri Feb 23, 2018 4:58 pm
Forum: archive submissions
Topic: Prestel and Teletext Adaptor ROMs
Replies: 2
Views: 414

Prestel and Teletext Adaptor ROMs

Whilst digging through a box of old stuff, I found the following four ROMs which I've "imaged". The first one appears to be an early version for the Prestel Adaptor (the version on mdfs.net is v1.10) PRS-1.00: PRESTEL 1.00 (C)1984SofMac The next three appear to be an early version of what became ATS...
by johnkenyon
Thu Feb 22, 2018 9:29 am
Forum: hardware
Topic: Solidisk Tic-Toc RTC
Replies: 34
Views: 6081

Re: Solidisk Tic-Toc RTC

Have to smile, it assumes 20th century, ie. Feb 1918!! Reading manual, shows the various registers, there's not one for century as best I can tell. Not sure whether it's good or not our friend Jon's HADFS60 doesn't pick up date from Tic-Toc as it does in the Master, albeit not tried Jon's fsys on m...
by johnkenyon
Tue Feb 20, 2018 11:07 am
Forum: hardware
Topic: BeebSCSImini
Replies: 45
Views: 2711

Re: BeebSCSImini

the machine hangs at the Acorn ADFS message The usual reason for this is that ADFS uses an odd type of detection on boot to see if the SCSI card is present. Basically it sends a pattern of data which (if a board is connected) it can read back from one of the data latches on the board. BeebSCSI emul...
by johnkenyon
Mon Feb 19, 2018 3:38 pm
Forum: software: other
Topic: Hacking the school Econet
Replies: 15
Views: 1033

Re: Hacking the school Econet

My technique was to keep my eyes peeled for one of the two teachers leaving the Network Manager menu program on an unattended computer. The sequence then went something like. 1) Hit break on the computer logged in with a privileged account. 2) *PRIV <myid> S 3) Hit break again 4) Move to another com...
by johnkenyon
Sat Feb 10, 2018 7:51 pm
Forum: other vintage computer hardware, software and games
Topic: Solutions for a sheered screw
Replies: 11
Views: 490

Re: Solutions for a sheered screw

danielj wrote:I'm wondering if I can just unfill the old head, unscrew it and do as Mark said. I can't work out what size screw it was - it seems to be 4.4mm diameter... That doesn't seem to correlate to anything?

d.
Possibly a BA thread/screw?
by johnkenyon
Thu Feb 08, 2018 11:08 pm
Forum: hardware
Topic: Kempston Competition Pro
Replies: 12
Views: 535

Re: Kempston Competition Pro

This arrived today with my Master:- 3443F3D0-A70C-4E9A-A8AF-9A7A0C6B5B31.jpeg How do I test a digital joystick? Do any games support them? Thus far google has not helped me much but to be fair I have had a pretty bad day so could well be me not searching very well! You are testing 6 microswitches w...
by johnkenyon
Thu Feb 08, 2018 3:14 pm
Forum: hardware
Topic: BBC controlled CD Jukebox, great find but need the space!
Replies: 49
Views: 3769

Re: BBC controlled CD Jukebox, great find but need the space!

You may have to drag another Master into the fray, connecting them via the serial ports Yeah, but the Master in MAME needs alot of work before that can happen, so won't be happening anytime soon. From the flyers there are three variants, and currently have the Discmate and Discmonitor that form the...
by johnkenyon
Wed Feb 07, 2018 11:29 pm
Forum: hardware
Topic: BBC controlled CD Jukebox, great find but need the space!
Replies: 49
Views: 3769

Re: BBC controlled CD Jukebox, great find but need the space!

Here are the DiscMaster Hideaway and Wallbox ROMs Thanks. We get a different DATA CARTRIDGE NOT FOUND screen: 0000.png But when I insert the cartridge it just hangs, so recognises the cartridge but missing something. Investigation required ... I'm assuming that the screen shot is from the wallbox. ...