Search found 4520 matches

by MartinB
Mon Oct 23, 2017 4:45 pm
Forum: hardware
Topic: high density disks
Replies: 155
Views: 21181

Re: high density disks

Nightmare scenario - a flurry of rekindled interest in something you devised but last looked at 6+years ago.... :shock: :lol: Jumping first to the final (v2) mod schematic.... Acorn 177x HD media mod V2.JPG ....there are separate inputs to the host computer (Beeb, Master or Elk) for drives 0 and 1 (...
by MartinB
Sun Oct 22, 2017 7:02 pm
Forum: hardware
Topic: high density disks
Replies: 155
Views: 21181

Re: high density disks

I’d all but forgotten about this stuff because when using my two development Beebs that both have the auto-density mod fitted, I don’t even notice if a given 3.5” disc is DD or HD - it’s that reliable and transparent for me. With HD 5.25 floppies I of course have to manually flick the drive density ...
by MartinB
Mon Oct 16, 2017 8:34 pm
Forum: off-topic
Topic: Learning old stuff let me make new stuff
Replies: 1
Views: 119

Re: Learning old stuff let me make new stuff

Stephen - just came across this whilst looking for some UPURS stuff! Sorry I missed it and you are very kind sir :oops: - I wont get into smoke blowing but you too contribute a wealth of fascinating Beeb-related info and other topical goodies (e.g. the digital safe =D> ) as do most folk on here.... ...
by MartinB
Sun Oct 15, 2017 7:27 pm
Forum: wanted
Topic: WTB: 2716 EPROM
Replies: 12
Views: 284

Re: WTB: 2716 EPROM

No worries Jon 8)
by MartinB
Sun Oct 15, 2017 7:02 pm
Forum: hardware
Topic: WE 32K RAM Card Repair
Replies: 55
Views: 1564

Re: WE 32K RAM Card Repair

The advantage that the Tube, the 1Mhz Bus, the disc interface and indeed most ‘designed’ IDC ribbon cable-based interfaces enjoy, is that the active signal lines are interleaved with 0v (reference ground) lines and this reduces the potential for significant crosstalk on longer cable runs. ‘Evolved’ ...
by MartinB
Sat Oct 14, 2017 9:03 am
Forum: wanted
Topic: WTB: 2716 EPROM
Replies: 12
Views: 284

Re: WTB: 2716 EPROM

Bit late but did you get sorted Jon? I have a few here, HN462716G (RS 309-379), which are probably new or very little used - I can erase and test program a couple if you're still wanting. Postage only so I guess a pound or two First Class large letter, would be early next week for posting.... 8)
by MartinB
Sun Oct 08, 2017 12:35 pm
Forum: for sale / freebies
Topic: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE
Replies: 109
Views: 4407

Re: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE

You can’t though use EUP as the necessary ‘hidden’ ram host for any &E00 disc FS (I don’t think so anyway.... :-k ) If you use a swram 256 chip (not eeprom) ACP DFS &E00 works Nice one Col - takes an idiot like me to design something and a genius like you to explain what it can do.... #-o :...
by MartinB
Sat Oct 07, 2017 7:40 pm
Forum: for sale / freebies
Topic: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE
Replies: 109
Views: 4407

Re: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE

Hi Derek :) Alex ( sixxdog_uk ) will confirm but I’m sure he still sells these and I think he can supply bare boards, kits or fully-built EUP’s. I suggest you send him a PM if he doesn’t pop up within a few days. a) The EUP on-board memory chip (e.g. an eprom) can be a 16k single-rom id device or a ...
by MartinB
Fri Oct 06, 2017 9:30 pm
Forum: hardware
Topic: Electron Plus 1 (or Master 128) Cartridge Sockets
Replies: 25
Views: 1488

Re: Electron Plus 1 (or Master 128) Cartridge Sockets

All my carts happily mix and match mechanically between the Elk and Master. (Did you notice I measured some for you btw?)
by MartinB
Fri Oct 06, 2017 5:42 pm
Forum: hardware
Topic: The ultimate function key strip?
Replies: 6
Views: 367

Re: The ultimate function key strip?

Nothing fancy but you can use cheap I2C-based displays with my I2C rom..... https://www.youtube.com/v/bwMH4ng3lv0&hl=en&fs=1 10 REM * LCD TEST PROGRAM * 20 REM * 4-BIT INIT * 25 : 30 PROC_INIT 40 M$="BBC Computer 32K Acorn 1770 DFS" 50 FORC=1TOLEN(M$) 60 D$=MID$(M$,C,1) 70 C%=ASC(D...
by MartinB
Fri Oct 06, 2017 2:57 pm
Forum: hardware
Topic: Electron Plus 1 (or Master 128) Cartridge Sockets
Replies: 25
Views: 1488

Re: Electron Plus 1 (or Master 128) Cartridge Sockets

Just measured (with digi-calipers) the pcb tongues of two genuine Acorn BBC Master carts and both are 56.4mm
by MartinB
Thu Oct 05, 2017 5:25 pm
Forum: for sale / freebies
Topic: VideoNuLA boards
Replies: 34
Views: 1596

Re: VideoNuLA boards

If I'm reading Toby's page correctly, you can get 28-pin headers a lot cheaper - £0.60 for one + VAT + £3.95 postage as far as I can see?

https://www.toby.co.uk/content/catalogu ... =606-xx-R1


Toby DIL headers.JPG
by MartinB
Wed Oct 04, 2017 5:04 pm
Forum: hardware
Topic: WE 32K RAM Card Repair
Replies: 55
Views: 1564

Re: WE 32K RAM Card Repair

Here you go... 8)
by MartinB
Thu Sep 28, 2017 5:14 pm
Forum: programming
Topic: Differences between BASIC1/2 and BASIC4 in handling an EVAL?
Replies: 20
Views: 376

Re: Differences between BASIC1/2 and BASIC4 in handling an EVAL?

Can you post a disc image so people can help...?
by MartinB
Tue Sep 26, 2017 10:26 pm
Forum: archive submissions
Topic: BBC Monitor - others
Replies: 1
Views: 110

Re: BBC Monitor - others

That's great Col - some considerable time ago, I promoted BBC Monitor over on Retrosoftware and noted at the time that we didn't have the originally supplied accompanying software so this is an excellent find. (Assuming I haven't previously missed anyone else beating you to it...!) Maybe the admins ...
by MartinB
Tue Sep 26, 2017 6:21 pm
Forum: hardware
Topic: Watford Electronics 13 ROM board
Replies: 9
Views: 725

Re: Watford Electronics 13 ROM board

In this PSU thread, I measured the +5v current draw of a busy Model B at 2.1A.....

Beeb 5v current draw.JPG


...so given that the stock PSU has a +5v rating of 3.75A, that suggests a theoretical headroom of over 1600mA.
by MartinB
Sun Sep 24, 2017 9:56 am
Forum: hardware
Topic: 5 pin din domino pcb mount sockets
Replies: 19
Views: 648

Re: 5 pin din domino pcb mount sockets

This is the configuration I use for UPURS whose standard speed is 115k baud but it works happily at 230k baud too. Modern USB-serial adaptors perform better than legacy RS232 ports at higher speeds but as long as the given host supports robust CTS/RTS handshaking then I've never found a remote devic...
by MartinB
Sat Sep 23, 2017 8:41 am
Forum: hardware
Topic: 5.25" Floppy drive write-protect fault
Replies: 12
Views: 392

Re: 5.25" Floppy drive write-protect fault

To be fair, you're now pulling the discussion in other directions. In the context of resolving Brian's reported problem, you originally stated.... If you want to completely override write protect, you can do that between the drive and the Beeb. It's pin 28 of the connector; disconnect it from the dr...
by MartinB
Fri Sep 22, 2017 8:43 am
Forum: hardware
Topic: 5.25" Floppy drive write-protect fault
Replies: 12
Views: 392

Re: 5.25" Floppy drive write-protect fault

Well done! Easy! =D> Martin, FYI, the drive PCB is marked 'TEC' CFE61-05004. That means the drive is a TEC 50x where x is likely 1, 3 or 4 and this determines the tracks, sides, densities and capacities etc.. You'd still need to find a model label to know for sure - if it is the basic 501 for exampl...
by MartinB
Fri Sep 22, 2017 8:00 am
Forum: hardware
Topic: 5.25" Floppy drive write-protect fault
Replies: 12
Views: 392

Re: 5.25" Floppy drive write-protect fault

Yes, I'm sure! :wink: It is perfectly possible to also implement a soft-protect function in the host fs, in DFS there's a nod to this with the *ENABLE switch for heavily destructive write commands. You could also have say a global disc *WPROT <ON / OFF> but none of this affects or interacts with the...
by MartinB
Thu Sep 21, 2017 10:42 pm
Forum: hardware
Topic: 5.25" Floppy drive write-protect fault
Replies: 12
Views: 392

Re: 5.25" Floppy drive write-protect fault

Write Protect on disc interface pin 28 is an output from the drive notifying the host that a write-protected disc is present in the drive and that the drive has locally inhibited writes. Disconnecting and tying that line high into the host will indeed make the latter unaware of the write protect but...
by MartinB
Tue Sep 19, 2017 8:51 pm
Forum: for sale / freebies
Topic: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE
Replies: 109
Views: 4407

Re: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE

facebook ? Is that some sort of acne...? :-k
by MartinB
Tue Sep 19, 2017 8:28 pm
Forum: for sale / freebies
Topic: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE
Replies: 109
Views: 4407

Re: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE

Hello gents and thanks for the responses. I tend to get shed loads of enquiries about my stuff either directly through email (my address is very much out there) or through Paul's website. It's surprising how many people don't embrace Stardot as the centre of the Beeb retro-universe but I typically t...
by MartinB
Tue Sep 19, 2017 6:13 pm
Forum: for sale / freebies
Topic: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE
Replies: 109
Views: 4407

Re: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE

Ah, ok - thanks Dave. I just wondered because I've steered a couple of people over here recently who've been enquiring about an EUP - they usually arrive through Paul V's site but no worries, they hopefully won't mind a little wait. Alex' good health come top of the list... 8)
by MartinB
Tue Sep 19, 2017 4:57 pm
Forum: for sale / freebies
Topic: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE
Replies: 109
Views: 4407

Re: ELECTRON User Port & ROM/RAM Board with UPURS - NOW AVAILABLE

Has anyone seen or heard from Alex lately ? He's been a bit thin on the ground recently.....?
by MartinB
Thu Sep 14, 2017 8:48 pm
Forum: hardware
Topic: Opus disc drive help
Replies: 8
Views: 222

Re: Opus disc drive help

I don't have any experience of the SPI fs so I don't know how (or even if) it works with a real floppy drive. What version is the Watford DFS, i.e. what boot-up message does that give? Ah, you said you can boot into " DFS and Watford electronics DFS " so in addition, what 'DFS' are you ref...
by MartinB
Thu Sep 14, 2017 8:15 pm
Forum: hardware
Topic: Opus disc drive help
Replies: 8
Views: 222

Re: Opus disc drive help

You have a Model B I believe so you don't have that facility. Which DFS do you have fitted? (Should report on the switch-on/reset banner under the Beeb 32k line.) If it were a drive step speed issue, that's controlled by the set of pcb links (possibly upgraded to DIL switches) at the bottom right of...
by MartinB
Thu Sep 14, 2017 7:29 pm
Forum: hardware
Topic: Opus disc drive help
Replies: 8
Views: 222

Re: Opus disc drive help

Do you know if the drive is a 40 or 80 track? Sounds like perhaps it's only a 40 and you're trying 80T discs?
by MartinB
Thu Sep 07, 2017 5:32 pm
Forum: hardware
Topic: Retro Cassette recorders
Replies: 12
Views: 464

Re: Retro Cassette recorders

It has according to the picture in the manual.....

cassette.JPG


manual.pdf
(7.59 MiB) Downloaded 4 times
by MartinB
Tue Sep 05, 2017 12:55 pm
Forum: software: other
Topic: Can we have useful BASIC with no IF statements?
Replies: 35
Views: 1218

Re: Can we have useful BASIC with no IF statements?

Good work lminstur.... =D>

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