Search found 4667 matches

by MartinB
Thu Apr 12, 2018 9:32 am
Forum: hardware
Topic: Unknown Sideways RAM / ROM adapter
Replies: 7
Views: 337

Re: Unknown Sideways RAM / ROM adapter

....then MartinB has developed some utilities, which should work for you. Yes, EELOAD works fine with SWR and there are both disc and rom-based version of the utilities. (By the way Ken, I haven't forgotten about the anomalies you kindly reported and I will soon be getting around to releasing an ud...
by MartinB
Tue Apr 10, 2018 5:38 pm
Forum: programming
Topic: Keyboard Buffer
Replies: 6
Views: 205

Re: Keyboard Buffer

:roll:

JGH wrote:No, the keyboard buffer is in MOS workspace, not in language workspace, and it is at &03E0-&03FF

Read my reply - I said exactly that.

and wrote:&700 is BASIC's command input buffer

I said that too and I was being helpful with extra information.
by MartinB
Tue Apr 10, 2018 10:13 am
Forum: programming
Topic: Keyboard Buffer
Replies: 6
Views: 205

Re: Keyboard Buffer

I often needs to pull things out of the command line for my utility programs and the the characters are always in readable ASCII - the buffer is in the $700 region for BASIC (&3E00-&3FF for OS) but there's OS calls to dynamically find the start address and to pull characters (I think!).
by MartinB
Sat Apr 07, 2018 8:22 am
Forum: hardware
Topic: Testing Beeb's analogue port
Replies: 17
Views: 470

Re: Testing Beeb's analogue port

Apart from scrambling the data bus, which is highly unlikely I feel, the only way the ADC could potentially 'hang' the Beeb would be by it's generating permanent or continuous End of Conversion (EOC) interrupts (or strictly Events to the OS) which might possibly drag the OS into a tight servicing lo...
by MartinB
Fri Apr 06, 2018 7:50 pm
Forum: hardware
Topic: Testing Beeb's analogue port
Replies: 17
Views: 470

Re: Testing Beeb's analogue port

As often as not, problems with the analogue port are due to cracked joints at the motherboard_to_15-way connector interface due to repeated waggling when plugging and unplugging joysticks. It generally doesn’t lead to ‘crashing’, just joystick-related intermittency and weirdness, but IMHO resolderin...
by MartinB
Fri Apr 06, 2018 6:05 pm
Forum: hardware
Topic: Testing Beeb's analogue port
Replies: 17
Views: 470

Re: Testing Beeb's analogue port

For a quick test, I just use this.... 10 PRINT~ADVAL(0)AND3;" ";~ADVAL(1);" ";~ADVAL(2);" ";~ADVAL(3);" ";~ADVAL(4) 20 GOTO10 When run, the fire buttons are reflected in the first column as 0,1, 2 or 3 depending on the combination of the two being pressed and ...
by MartinB
Tue Apr 03, 2018 10:28 pm
Forum: hardware
Topic: BBC Model B - memory or video fault?
Replies: 6
Views: 254

Re: BBC Model B - memory or video fault?

Run the test program here in all the screen modes (with repeats as necessary) and see if you get either a memory IC fault reported or if you observe any unusual video artefacts on the display.
by MartinB
Mon Apr 02, 2018 9:09 pm
Forum: hardware
Topic: Hard disks just spin
Replies: 1
Views: 138

Re: Hard disks just spin

It’s a long shot but is there a chance you could have reversed the connector when plugging the drives into the original Beeb, or even have the connector offset by a pin row? I only ask because a constantly spinning drive is usually a reversed connector.....
by MartinB
Thu Mar 29, 2018 7:08 pm
Forum: hardware
Topic: Pegasus, New AP5 and New AP3/4 Painted Metal case
Replies: 28
Views: 2006

Re: Pegasus, New AP5 and New AP3/4 Painted Metal case

Daniel wrote:...and an epic


Thanks Daniel, I'll take the complement... :D
by MartinB
Thu Mar 29, 2018 12:20 pm
Forum: wanted
Topic: B+128 keystrip & upper case
Replies: 30
Views: 797

Re: B+128 keystrip & upper case

Nice job, these will be very useful.... =D> :D
by MartinB
Tue Mar 27, 2018 8:35 pm
Forum: for sale / freebies
Topic: P.M.F. Barcode Reader
Replies: 20
Views: 1131

Re: P.M.F. Barcode Reader

I'll endeavour to dig it out and make an image. If I can find it reasonably quickly tonight then I'll post it later... Here you go, courtesy of 10 seconds with UPURS..... :D " Barcode Support ROM Version 0.1 (C) Mike Ginns 1987 " barcode.zip Note that I dumped it as a 16k rom (the physica...
by MartinB
Tue Mar 27, 2018 11:44 am
Forum: for sale / freebies
Topic: P.M.F. Barcode Reader
Replies: 20
Views: 1131

Re: P.M.F. Barcode Reader

A ROM version is also mentioned in the original post on this thread. I did have a play with this after Kieran sent it to me and although I can't rememeber how I drove it software-wise (I've slept since... :roll:), I think I must have the used the rom so I'll endeavour to dig it out and make an imag...
by MartinB
Sun Mar 25, 2018 6:02 pm
Forum: hardware
Topic: Questions about BBC B memory fault
Replies: 18
Views: 508

Re: Questions about BBC B memory fault

I've run pretty much every test I can think of on the machine, and I'm still seeing the occasional speckle on a mode 0 screen. It often happens when you type. In fact, the same location on the screen changes a bit the more you type. You don't have any misbehaving roms in there do you? I only ask be...
by MartinB
Sun Mar 25, 2018 12:12 pm
Forum: software: other
Topic: Forbidden characters in filenames
Replies: 6
Views: 254

Re: Forbidden characters in filenames

The Advanced Disc User Guide says....

35108E4E-0601-4C80-B280-2E29543FA7C7.png


That’s DFS but I imagine it didn’t change for ADFS.
by MartinB
Sun Mar 25, 2018 9:38 am
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

Re: MartinB's Memory Test Tool

8)
by MartinB
Sun Mar 25, 2018 8:23 am
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

Re: MartinB's Memory Test Tool

Hi again Ken - I really feel that this is heading to a pointless place. Yes, some chips have internal pull-ups (and I knew about the 139) but you don't design around these things. The general safe rule is don't leave externally floating inputs in logic circuits. However, all of this irrelevant here....
by MartinB
Sun Mar 25, 2018 7:35 am
Forum: hardware
Topic: HostFS and microcontrollers?
Replies: 48
Views: 2506

Re: HostFS and microcontrollers?

Martin, this looks like the race condition I pointed out to you way back when (2013, according to my email history... wow that was a long time ago!). Hi Stephen - yes it is and I did acknowledge that to Dave a few posts further up.... Yes, now you mention it, I think Stephen did tell me about that....
by MartinB
Sun Mar 25, 2018 7:23 am
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

Re: MartinB's Memory Test Tool

I had a suspicion that you (or someone) might suggest that and I did consider it but ultimately decided no, it isn't a valid option. If you look at the snip below, you'll see that without S25 fitted, the input to the 139 is floating and this could actually give variable results. So, its not within t...
by MartinB
Sat Mar 24, 2018 11:20 pm
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

Re: MartinB's Memory Test Tool

Ha! Cheers Col and thanks for the WAV and MP3 files, great idea.... =D> 8)
by MartinB
Sat Mar 24, 2018 11:16 pm
Forum: hardware
Topic: read out 23128 rom
Replies: 7
Views: 382

Re: read out 23128 rom

Although they are mask-programmable read-only devices, they were designed to be pin-compatible with their eprom equivalents so you shouldn’t be struggling. One minor point is that the chip select at pin 27 is actually programmable so you could try pulling that low instead of high in case it has been...
by MartinB
Sat Mar 24, 2018 10:03 pm
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

Re: MartinB's Memory Test Tool

Here is version 3 of the memory tester which now adjusts its memory test range and faulty IC number output to cater for both the two possible positions of memory configuration Link S25 and for the potential inversion of same. Thanks to Ken Lowe for suggesting this feature. On running, there are two ...
by MartinB
Sat Mar 24, 2018 7:50 am
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

Re: MartinB's Memory Test Tool

That's not a bad idea Ken - I could limit the test range to &3FFF if it's effectively a 16k machine and match the true physical IC's to the link inversion state. I'll do a V2 later today. Ta... 8)
by MartinB
Sat Mar 24, 2018 12:00 am
Forum: hardware
Topic: MartinB's Memory Test Tool
Replies: 12
Views: 518

MartinB's Memory Test Tool

EDIT : Later today, I will update to a V2 (V3 counting the original!) adding S25 link state handling as suggested by Ken L . The version below works fine but but be aware that if you have changed the default config of the S25 link then you need to be careful when interpreting the results. F...
by MartinB
Fri Mar 23, 2018 11:36 pm
Forum: hardware
Topic: Questions about BBC B memory fault
Replies: 18
Views: 508

Re: Questions about BBC B memory fault

Ah, thanks Andy - that's great and no worries, happy to help.... =D> I can see though that you've missed a couple of brackets out in line 150 - should be IC(s) and not ICs . It affects the print formatting and therefore seriously niggles my OCD... 8-[ =; I'm going to create a new thread with an atta...
by MartinB
Fri Mar 23, 2018 10:28 pm
Forum: hardware
Topic: Questions about BBC B memory fault
Replies: 18
Views: 508

Re: Questions about BBC B memory fault

Now I need you to put your faulty IC63 back in and confirm that my modified program does correctly point the finger at that chip.... [-X [-( :roll:

:lol:
by MartinB
Fri Mar 23, 2018 10:23 pm
Forum: hardware
Topic: Questions about BBC B memory fault
Replies: 18
Views: 508

Re: Questions about BBC B memory fault

Mark's first program is randomly peeking screen memory and expects therefore always to find zero (black) because of the CLS in line 10. However, the code is flawed because it can attempt to peek one location higher than the maximum screen address, i.e. &8000 where the highest should be &7FFF...
by MartinB
Fri Mar 23, 2018 9:40 pm
Forum: hardware
Topic: Questions about BBC B memory fault
Replies: 18
Views: 508

Re: Questions about BBC B memory fault

Ok, I've modified my program so it will both report the failed address and indicate the ram chip (or chips) that have failed at bit-level. The " Bit Hi IC(s) " are the memory chips where there is a bit stuck high (at a logic 1) and the " Bit Lo IC(s) " are the memory chips where ...
by MartinB
Fri Mar 23, 2018 6:45 pm
Forum: hardware
Topic: Questions about BBC B memory fault
Replies: 18
Views: 508

Re: Questions about BBC B memory fault

My program will only tell you which bank has failed (although with variable inspection after halting it can actually show the chip), it was more designed to simply show whether or not there is a ram fault at all and also, whether the video circuitry is correctly accessing and displaying the ram. Hav...
by MartinB
Fri Mar 23, 2018 12:11 am
Forum: hardware
Topic: Pulling a bad tooth out (BBC UHF modulator)
Replies: 9
Views: 497

Re: Pulling a bad tooth out (BBC UHF modulator)

Are you sure you’re not hearing the Beeb’s ubiquitous 1MHz bus noise? This is a shushing/buzz that varies with the Beeb’s activity and key presses. It can be cured with the addition of a resistor (no details to hand as I’m in bed, you could search the forum) but like the modulator, it’s highly unlik...
by MartinB
Thu Mar 22, 2018 8:56 pm
Forum: wanted
Topic: B+128 keystrip & upper case
Replies: 30
Views: 797

Re: B+128 keystrip & upper case

Ok, so these are therefore the diaganol measurements of the rectangular cream area within each sticker. Referring to the first picture I posted of the computer as a whole....

Top left corner of case : 71mm

Right-hand of keystrip : 88mm

Bottom right of black keyboard surround : 24mm