Search found 2262 matches

by jms2
Sun Sep 22, 2019 8:24 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Fixed that, by reference to the Acorn client startup routine. However, the effect is still the same... so I think that maybe what I am seeing is an assembly problem after all (ie, the logic's OK but the code is just assembling wrong because I haven't put the labels in correctly). What I'm seeing is ...
by jms2
Sat Sep 21, 2019 9:52 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Ah, I think I can see what the problem is. After the host code transfers the language, it then tries to run it by transferring the execution address. However, whereas with the old arrangement the transfer of the address would automatically run the code. However, with my revisions code can only be ru...
by jms2
Fri Sep 20, 2019 7:40 pm
Forum: hardware
Topic: A difficult decision
Replies: 16
Views: 317

Re: A difficult decision

I would keep both, for this reason: I too had (still have) an expanded BBC B, with a WE ram board and various ROMS. It's a great machine, but the problem is that it isn't 100% compatible with some games. So I got a plain vanilla Issue 7 machine with Acorn DFS, which I use for running games on. The o...
by jms2
Thu Sep 19, 2019 10:06 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

I seem to be getting somewhere! I have made several revisions to the code to produce the attached. This gets as far as the BASIC title, but hangs before showing the prompt. It's a fairly serious hang as well, because the cursor freezes! I think that this is probably caused by a mistake in my logic r...
by jms2
Tue Sep 17, 2019 6:11 am
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Thanks for disentangling the parasite OSBYTE code - I was getting there, but the meaning was eluding me! You're absolutely right that simply removing the stack clear doesn't solve the problem. I tried it, and it didn't help at all, which led me to disassemble the whole thing. I see your point about ...
by jms2
Mon Sep 16, 2019 10:37 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Posts crossed. Yes, that is the same conclusion that I came to.
by jms2
Mon Sep 16, 2019 10:36 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

:D That's good - I have just about managed to follow all of that, and also cross-refer to what is the same and what is different in the E2P OS. One major difference is the use of completely different registers, but this isn't a fault, it's just how the hardware works. For example, there is a special...
by jms2
Mon Sep 16, 2019 7:13 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Excellent, that's just what I was looking for, thanks. The "set execution address" stage is the bit that I was struggling to find, but now I know what to look for it should be a lot easier. By playing with BeebEm I was able to discover the bug that you describe, and reproduce it - basically any *RUN...
by jms2
Sun Sep 15, 2019 7:11 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

I forgot to include the BeebAsm file. Here it is, if anyone is curious. By the way, because the executable contains three chunks of code which have to be moved to other addresses before they are executed, I have had to perform some cumbersome addition and subtraction of correction factors to absolut...
by jms2
Sun Sep 15, 2019 7:05 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

I'm still working on this, to the extent that I have managed to reverse engineer the source for the final version of the E2P OS. It's in BeebAsm format, and it is reasonably well commented and labelled. It assembles to create an identical binary to the one I disassembled, which is v2.4 plus a few sl...
by jms2
Tue Aug 27, 2019 8:06 pm
Forum: hardware
Topic: Gotek Problems on My Electron
Replies: 22
Views: 414

Re: Gotek Problems on My Electron

The problem I had with my similar setup was getting the drive number configuration right. The Plus 3 drive is Drive 0, so the Gotek should be jumpered as Drive 1. Have you moved the Drive Select jumper on the Gotek? EDIT: Also, is the cable the right way round where it goes into the Plus 3 (I'm not ...
by jms2
Sat Aug 10, 2019 8:49 pm
Forum: hardware
Topic: Gotek
Replies: 4
Views: 308

Re: Gotek

I don’t know anything about Amstrads, but I don’t see why you would need to alter the Gotek at all. It pretends to be a disc drive, so all you should need to do is plug it into your bbc, make sure there are some .ssd files on it to load, and tweak the config file to contain the right settings for Ac...
by jms2
Thu Aug 08, 2019 7:45 pm
Forum: hardware
Topic: Wiring question regarding Acorn Electron ROMs
Replies: 6
Views: 245

Re: Wiring question regarding Acorn Electron ROMs

This is the brief version: You’re right that CE is the correct way to control access to the rom. To do this, you need to build a circuit (probably using logic gates) to perform address decoding. The address you need to detect is &FE05. When you identify that this address is on the address bus, you t...
by jms2
Sun Aug 04, 2019 8:19 pm
Forum: introduce yourself
Topic: Hello from Derby!
Replies: 20
Views: 374

Re: Hello from Derby!

Hi Julie, good luck with the project. There are a couple of us Beeb owners in Derby!
by jms2
Tue Jul 30, 2019 8:08 pm
Forum: introduce yourself
Topic: A resurfaced Beeb user :-)
Replies: 16
Views: 596

Re: A resurfaced Beeb user :-)

Hello and welcome Grant!

I really enjoyed following your Multicomp article and getting a board working. Your website is terrific!
by jms2
Sun Jul 28, 2019 3:36 pm
Forum: software
Topic: Directory Referencing in BASIC
Replies: 9
Views: 348

Re: Directory Referencing in BASIC

I don't have any reference manuals to hand, but isn't there is system variable that contains this information? For example, within an Obey file the directory that the file was run from is Obey$Dir. Could it be Run$Dir?
by jms2
Sun Jul 14, 2019 10:15 pm
Forum: software: classic games
Topic: Volcano on the Elk?
Replies: 16
Views: 993

Re: Volcano on the Elk?

This is great - possibly better than the BBC version due to being easier!
by jms2
Mon Jul 08, 2019 10:57 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Right, I have patched version 0.1 but not had time to test it out yet. In assembling the code, I noticed that this early version is some 512+ bytes larger than v2.4. The manual actually makes reference to this, and explains that the reason is the addition of three new features, *GO, *E2POFF and a no...
by jms2
Mon Jul 08, 2019 10:44 pm
Forum: software: classic games
Topic: Volcano on the Elk?
Replies: 16
Views: 993

Re: Volcano on the Elk?

Nice one! I stand corrected then, and I look forward to giving it a go. I wonder why Acornsoft never converted it?
by jms2
Sun Jul 07, 2019 8:31 am
Forum: emulators
Topic: Is Horizon a dirty word hereabouts?
Replies: 7
Views: 680

Re: Is Horizon a dirty word hereabouts?

It is possible, at least on the Windows version of BeebEm, to reconfigure the keyboard mapping. Is that feature missing from the Mac version?
by jms2
Sat Jul 06, 2019 6:12 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

That's v0.1, which is not the same as the later v2.4 that I'm dealing with. However, it does have the same bug, so it would be much easier to trial my proposed solution within that first before making my own source for v2.4. Good call!
by jms2
Sat Jul 06, 2019 7:12 am
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

Thanks - I was looking for some independent confirmation that I was on the right lines and so I'm very grateful for your opinion. Whilst I can see what the changes need to be, the way the program self-unpacks into both processors means that it won't be possible to simply poke corrected bytes into it...
by jms2
Fri Jul 05, 2019 7:23 am
Forum: programming
Topic: switching Beebem to US format
Replies: 3
Views: 186

Re: switching Beebem to US format

Yes. You need to find the existing BASIC2 rom in your emulator and replace it with BASIC3 from here: http://mdfs.net/Software/BBCBasic/BBC/ Exactly how you do this will depend on which emulator you are using. EDIT doh, I just noticed you already said Beebem! I can't recall exactly how to do it but i...
by jms2
Thu Jul 04, 2019 11:02 pm
Forum: hardware
Topic: Looking for inspiration - debugging E2P
Replies: 32
Views: 1350

Re: Looking for inspiration - debugging E2P

I think I may have figured this out. It has taken a great deal of studying the BBC Tube Host and client code to figure out how they work, and then looking at the E2P OS alongside. Tube operations are not something I am familiar with, so hopefully this makes sense... The BBC way On issuing a *RUN com...
by jms2
Thu Jul 04, 2019 9:04 pm
Forum: hardware
Topic: Open Source Logic Analyzer Experiments
Replies: 253
Views: 17575

Re: Open Source Logic Analyzer Experiments

Excellent, thanks.

So was I on the right lines earlier when I said that this kind of thing is an occupational hazard of not having the sync signal present? (It doesn't always generate the "fail" messages).
by jms2
Thu Jul 04, 2019 7:26 pm
Forum: software: classic games
Topic: Volcano on the Elk?
Replies: 16
Views: 993

Re: Volcano on the Elk?

I doubt it actually - Volcano runs in Mode 2 and has a huge number of sprites moving around on the screen. The Electron probably couldn't do that because it slows down so much in Modes 0-3.

A Mode 5 version would probably be possible... a challenge for someone on here?
by jms2
Thu Jul 04, 2019 7:22 pm
Forum: hardware
Topic: Open Source Logic Analyzer Experiments
Replies: 253
Views: 17575

Re: Open Source Logic Analyzer Experiments

OK, so just to be completely certain I downloaded the file off here, saved it back onto my machine and issued the following commands, with the results shown: $ ./decode6502 -h -s --sync= data.bin > data.txt $ wc -l data.txt 450318 data.txt $ grep fail data.txt | wc -l 3 I tried this several times, i...
by jms2
Wed Jul 03, 2019 9:32 pm
Forum: hardware
Topic: Open Source Logic Analyzer Experiments
Replies: 253
Views: 17575

Re: Open Source Logic Analyzer Experiments

I'm already using that option: ./decode6502 -h -s --sync= data.bin > data.txt I thought that argument specifies that sync wasn't connected? If so, it's correct, and I'm already using it. In reality, sync is not connected, because sync isn't available on the Tube port. It would be available on my own...
by jms2
Wed Jul 03, 2019 6:41 pm
Forum: hardware
Topic: Open Source Logic Analyzer Experiments
Replies: 253
Views: 17575

Re: Open Source Logic Analyzer Experiments

I just re-ran it and got 3 fails, which is a record - previously it was either 1 or 0. So here is a zipped version of the binary file. My plan is to use this to figure out what is going on in the software for my E2P board. The hardware is working fine, but I have discovered (with the help of JGH) th...
by jms2
Wed Jul 03, 2019 10:27 am
Forum: hardware
Topic: Open Source Logic Analyzer Experiments
Replies: 253
Views: 17575

Re: Open Source Logic Analyzer Experiments

Thanks for the offer but it turns out there is no need ... on running it a second time, it works fine! Brilliant! Thanks Dave. ???? : : RESET !! : A=?? X=?? Y=?? SP=?? N=? V=? D=? I=1 Z=? C=? D9CD : A9 40 : LDA #40 : A=40 X=?? Y=?? SP=?? N=0 V=? D=? I=1 Z=0 C=? D9CF : 8D 00 0D : STA 0D00 : A=40 X=??...