Search found 5189 matches

by MartinB
Tue Apr 23, 2019 9:41 pm
Forum: software: other
Topic: Toggling binary bits
Replies: 5
Views: 126

Re: Toggling binary bits

The code below shows some one-line BASIC binary bit twiddles for bit number B% in integer number M%. Note importantly that B% is the target bit number and the LSB is numbered 0. For example, B% is 0-7 for an 8-bit number (where M% is 0-255) and B% is 0-15 for a 16-bit number (where M% is 0-65535) 10...
by MartinB
Tue Apr 23, 2019 7:14 pm
Forum: hardware
Topic: Another BBC B Needs Fixing.
Replies: 20
Views: 494

Re: Another BBC B Needs Fixing.

Last night, I thought Russ was suggesting that he didn't even get the ' Bit Lo/Hi.. ' dialogue (which was somewhat impossible) but I see now that he's quite rightly querying the fact that there's no actual IC number reported after the failure detect dialogue. The reason for this is that the memory f...
by MartinB
Mon Apr 22, 2019 7:34 pm
Forum: hardware
Topic: Another BBC B Needs Fixing.
Replies: 20
Views: 494

Re: Another BBC B Needs Fixing.

I ran Martins test program and that sometimes passes and sometimes fails but does not return an IC! It returns the address buy no IC number.....? :shock: That’s confusing :? What exactly do you get as an output? The earlier versions just report the failing location but v3 converts the bit-level fai...
by MartinB
Mon Apr 22, 2019 6:35 pm
Forum: hardware
Topic: I2C 4 U
Replies: 393
Views: 24059

Re: I2C 4 U

Hi Dave :) Many apologies for the late reply, for some reason I’ve been unusually busy of late and have struggled somewhat for Beeb bandwidth - I even owe Ken a big apology because I've had one of his cracking IntegraB boards for nearly two weeks and although I've made a start, it's still not up and...
by MartinB
Fri Apr 19, 2019 10:53 pm
Forum: hardware
Topic: Deaf Acorn Electron not loading tapes etc
Replies: 17
Views: 370

Re: Deaf Acorn Electron not loading tapes etc

From the prompt, type..... *SAVE TEST 1000 5000 [ RETURN ] ....which will, after you press [ RETURN ] again in response to the prompt, give you a long period of whistles, growls and clicking as the two-digit on-screen display counts up. If your tape machine is in record, you /should/ be able to hear...
by MartinB
Wed Apr 17, 2019 5:31 pm
Forum: software: other
Topic: Copy tape images on the BBC
Replies: 10
Views: 418

Re: Copy tape images on the BBC

You are most welcome Andrew - my very small contribution to your generous efforts with the youth club 8) The two tapes aren't particularly about the games themselves but, as you wanted, are good to show the tape loading tedium. Paper Boy is particularly convoluted and whilst colourful, takes a signi...
by MartinB
Wed Apr 17, 2019 5:25 pm
Forum: stardot.org.uk
Topic: PM system, when is it activated for new users?
Replies: 6
Views: 101

Re: PM system, when is it activated for new users?

Normally, after 25 posts but if you can show that you're an all-round good egg, the admins will enable your PM's early in response to a heart-felt request on here..... :wink:
by MartinB
Sun Apr 14, 2019 10:20 pm
Forum: acorn atom and system
Topic: Using PC Floppy Drives ?
Replies: 6
Views: 195

Re: Using PC Floppy Drives ?

If you have a little time, you can read all the Beeb-relevant info and facts behind this HD/DD shenanigans in the HD floppies thread where it even concludes with a little mod circuit that allows the correct (and safe) use of 3.5” and 5.25” HD floppy media (including the use of so-called ‘PC Drives’)...
by MartinB
Sat Apr 13, 2019 11:24 am
Forum: hardware
Topic: Master IO Controller IC15 - Databus pins?
Replies: 4
Views: 114

Re: Master IO Controller IC15 - Databus pins?

This doesn't really answer your question but perhaps offers a clue in that checking the integrity of those two pin connections is called up in the Master Service Manual in the context of fault-finding both the 1MHz Bus and the Tube.... :-k

IC15.JPG
by MartinB
Fri Apr 12, 2019 6:17 pm
Forum: software: other
Topic: Copy tape images on the BBC
Replies: 10
Views: 418

Re: Copy tape images on the BBC

Ok Andrew, I’ll try and get a couple in the post tomorrow, I want to check-load them first so you know they’re good in case you have any loading ‘issues’ and in which case, you’ll know it’s your kit...... :wink:
by MartinB
Fri Apr 12, 2019 11:18 am
Forum: programming
Topic: 6502 LDA / LDX / LDY and Zero flag
Replies: 8
Views: 266

Re: 6502 LDA / LDX / LDY and Zero flag

Within that masswerk site there is also an excellent trio of online 6502 tools in a CPU emulator, an assembler and a disassembler. For questions such as yours where the behaviour of a flag is uncertain, you can quickly and simply perform a functional test on a 6502 and see what happens. Just assembl...
by MartinB
Thu Apr 11, 2019 6:23 am
Forum: software: other
Topic: Copy tape images on the BBC
Replies: 10
Views: 418

Re: Copy tape images on the BBC

Could an admin check that Andrew has PM's enabled please - I notice that he's only just reached 25 posts and I don't know if the enabling happens automatically or not? Ta.
by MartinB
Wed Apr 10, 2019 8:30 pm
Forum: software: other
Topic: Copy tape images on the BBC
Replies: 10
Views: 418

Re: Copy tape images on the BBC

Andrew - if you want to PM me your address, I’ll post you an original tape FoC for your youth club demo. You can keep the tape for future use, no need to return it.



.
by MartinB
Wed Apr 10, 2019 9:34 am
Forum: software: classic games
Topic: Getting started with Exile...
Replies: 21
Views: 593

Re: Getting started with Exile...

Presumably this should be > 64 unless A is to be left as is? If this is the decryption routine then the encrypyted characters being analysed already have 1 added and so, if the expectation is that the original text is formed of 'A' onwards, the test for the lowest value (with the +1 already added) ...
by MartinB
Tue Apr 09, 2019 6:30 am
Forum: hardware
Topic: BBC B+ 128K: Fault after warming up.
Replies: 75
Views: 1742

Re: BBC B+ 128K: Fault after warming up.

Just checked the B+ schematic, the 4164 IC's 55, 56, 60, 61, 64, 65, 66 and 67 map to data bus D0 - D7 respectively.
by MartinB
Tue Apr 09, 2019 5:54 am
Forum: hardware
Topic: BBC B+ 128K: Fault after warming up.
Replies: 75
Views: 1742

Re: BBC B+ 128K: Fault after warming up.

Kazzie wrote:Each RAM chip corresponds to one bit in every one of either the lower or upper 16k of addresses:

Code: Select all

   /CAS0 /CAS1
D0= IC61  IC53
D1= IC62  IC54
D2= IC63  IC55
D3= IC64  IC56
D4= IC65  IC57
D5= IC66  IC58
D6= IC67  IC59
D7= IC68  IC60
That's the Model B answer, have we switched from a B+?
by MartinB
Sat Apr 06, 2019 1:50 pm
Forum: for sale / freebies
Topic: FS: New ROM / RAM Expansion Board for BBC B
Replies: 36
Views: 1004

Re: FS: New ROM / RAM Expansion Board for BBC B

Mine arrived yesterday but was left with a neighbour so I've just retrieved it! :) Looks absolutely fantastic Ken, a real credit to your dedication and professionalism =D> 8) Thing is though, I've become terribly distracted by the ' free with every order ' packet of Haribo so sod the Integra-B, I'm ...
by MartinB
Fri Apr 05, 2019 6:27 pm
Forum: programming
Topic: Basic Programe for joystick
Replies: 10
Views: 334

Re: Basic Programe for joystick

Thank you. That's so cool. No worries, you are welcome Andrew 8) If you want it, here's an explanation of the (simple) technique I'm using..... DX% and DY% are actually ‘delta’ X & Y values representing the amount of change in position of the crosshair XY at each iteration. The analogue channels re...
by MartinB
Wed Apr 03, 2019 6:07 pm
Forum: programming
Topic: Basic Programe for joystick
Replies: 10
Views: 334

Re: Basic Programe for joystick

Here you go Andrew, I've made an ssd containing the test program if that helps you.

Joystick test.ssd
(1.25 KiB) Downloaded 5 times
by MartinB
Wed Apr 03, 2019 10:30 am
Forum: programming
Topic: Basic Programe for joystick
Replies: 10
Views: 334

Re: Basic Programe for joystick

Hi Andrew - personally, I use real floppy drives together with a system called UPURS but that's not a five-minute job to get configured and to be honest, I'm not sure what other people do use in these days of solid-state storage. Bearing in mind that in this instance, it's a fairly short program, co...
by MartinB
Tue Apr 02, 2019 9:47 pm
Forum: programming
Topic: Basic Programe for joystick
Replies: 10
Views: 334

Re: Basic Programe for joystick

I've just quickly adapted the below from my I2C Nunchuck test program but I have not tested it on a Beeb. You should be able to move the crosshairs around the screen at a variable rate but note that there are no screen boundary checks :) EDIT : Added simple screen boundary limiting 10 REM * JOYSTICK...
by MartinB
Mon Apr 01, 2019 4:56 pm
Forum: hardware
Topic: Today I found 3 Acorn computers in my loft!
Replies: 15
Views: 635

Re: Today I found 3 Acorn computers in my loft!

If you go here to Power Adaptors UK , you will find a huge choice of competitively priced AC/AC adaptors with many permutations of voltage versus current. For example, the one shown below is on Page 4 of the AC adaptors list and is a 36VA unit giving 18v AC @ 2A coming in at £12.66 inc. VAT with UK ...
by MartinB
Sat Mar 30, 2019 1:20 pm
Forum: programming
Topic: Assembly language text adventure
Replies: 38
Views: 826

Re: Assembly language text adventure

You say to " save space " but on your assembly language learning curve, have you appreciated that the memory area you are referring to is known as 'Zero Page' (ZP) and that this is very 'special' having dedicated (memory and time saving) addressing modes associated with it? The specific locations th...
by MartinB
Fri Mar 29, 2019 1:03 pm
Forum: software & utilities for the pc, mac or unix
Topic: Wires? Pah.....
Replies: 896
Views: 119991

Re: Wires? Pah.....

Actually Ian, a while ago we did have a long discussion about using these modules with UPURS in another thread.... https://stardot.org.uk/forums/viewtopic.php?f=3&t=10586&p=136538#p128748 What I can’t deduce from that is what the conclusions were? :? You suggested then that you had one or two module...
by MartinB
Fri Mar 29, 2019 11:33 am
Forum: software & utilities for the pc, mac or unix
Topic: Wires? Pah.....
Replies: 896
Views: 119991

Re: Wires? Pah.....

I was thinking perhaps that being an FTDI-based TTL module, the signal states would be as per the likes of the Tronisoft adaptors and yes, I do perform inversion in the UPURS RS232 core engine.

(I do know what the diodes and resistors do btw, I designed it remember.... :lol: )


.
by MartinB
Fri Mar 29, 2019 9:34 am
Forum: software & utilities for the pc, mac or unix
Topic: Wires? Pah.....
Replies: 896
Views: 119991

Re: Wires? Pah.....

Hi James - well, if you know that a given module can only drive all the RS232 lines at 0v to +5v (no negative) then no, you don’t need either the diodes or the resistors and for the latter, just connect the lines straight through. The passive components are there to protect against the legitimate us...
by MartinB
Thu Mar 28, 2019 3:06 pm
Forum: software & utilities for the pc, mac or unix
Topic: Wires? Pah.....
Replies: 896
Views: 119991

Re: Wires? Pah.....

If its FTDI then it should be ok. For the UPURS connection to the Beeb User Port via the cable (you will be making :wink:), you need to be able to clearly identify TxD, RxD, RTS, CTS and Ground on the adaptor. If you can't, then it's potentially a more difficult job.


.
by MartinB
Thu Mar 28, 2019 2:17 pm
Forum: software & utilities for the pc, mac or unix
Topic: Wires? Pah.....
Replies: 896
Views: 119991

Re: Wires? Pah.....

Hmmmm.... :-k Can you see what the chip is on which it's based - in particular, is it an FTDI device? Secondly, and very importantly, any such gadget MUST correctly implement CTS and RTS handshaking - an area where many many adaptors fall over because much of our familiar modern computer equipment d...
by MartinB
Thu Mar 28, 2019 1:27 pm
Forum: software & utilities for the pc, mac or unix
Topic: Wires? Pah.....
Replies: 896
Views: 119991

Re: Wires? Pah.....

For the latest package clicky here and for some supporting back-story, have a look at Paul Vernon's Retro-Kit UPURS pages. If you have any questions or comments, you can post on the first linked 'Wires? Pah...' thread. If you need to get a USB-RS232 adaptor, here’s the link to the recommended device...
by MartinB
Thu Mar 28, 2019 12:44 pm
Forum: hardware
Topic: I2C 4 U
Replies: 393
Views: 24059

Re: I2C 4 U

I second this. Awesome Work Martin. Thanks! No worries James, glad you're having fun - exactly my objective....! :) BTW - did you see on Page 11 of the thread where I posted some pics of how I've got the RTC module permanently mounted inside the Beeb? For me, its really good to have the clock as pa...