Search found 2196 matches

by jms2
Tue Apr 23, 2019 8:01 pm
Forum: software: classic games
Topic: Beeb games that work on the Elk
Replies: 2
Views: 102

Re: Beeb games that work on the Elk

Yes, quite a lot of BBC games do work. This was the subject of a few articles in Electron User in the early days as I recall, probably because Acorn were understandably vague in their advertising regarding the level of compatibility between the two machines, such that many Electron users started fro...
by jms2
Tue Apr 23, 2019 6:44 pm
Forum: software: other
Topic: Accessing sideways ram from an event handler
Replies: 7
Views: 124

Re: Accessing sideways ram from an event handler

It isn't clear to me what machine you are targetting either, is it the Elk then? Whoops, yes I should have said that. I don't know about the elk, nor if it is legal on the beeb, but in an interrupt, not calling the is or unknown code, I don't change &F4, but use it to restore romsel. I suspect that...
by jms2
Tue Apr 23, 2019 2:10 pm
Forum: software: other
Topic: Accessing sideways ram from an event handler
Replies: 7
Views: 124

Re: Accessing sideways ram from an event handler

Yes, I'm pretty sure... although my code doesn't use the JSR:

\A=rom number
PHA
LDA#12
STA &F4
STA &FE05

PLA
STA &F4
STA &FE05

Am I OK using the stack in this way?
by jms2
Tue Apr 23, 2019 12:33 pm
Forum: software: other
Topic: Accessing sideways ram from an event handler
Replies: 7
Views: 124

Re: Accessing sideways ram from an event handler

Good call. Yes I did, from memory I did: LDA romnumber STA &F4 STA &FE05 I also used the Electron-specific "double select" method where you select a high-numbered rom first and then the required rom. Another thing that I realized you need to do is read the current rom number from &F4 rather than fro...
by jms2
Tue Apr 23, 2019 11:45 am
Forum: software: other
Topic: Accessing sideways ram from an event handler
Replies: 7
Views: 124

Accessing sideways ram from an event handler

I have written a short piece of event-driven code which I'm using to monitor the contents of sideways ram for hardware testing purposes. It works, but is not 100% reliable - ie it crashes about 4 times out of 5. I suspect that some aspect of the way I am handling events is not quite right, but I can...
by jms2
Sun Apr 21, 2019 8:20 pm
Forum: general
Topic: Design a logo for ABug!
Replies: 25
Views: 2369

Re: Design a logo for ABug!

I have done some experimenting and have attached three files here: 1) The original logo as a PNG. 2) The logo with a transparent background instead of black. As I thought, this doesn't look great. 3) As above, but with a black outline around the edges. This is better but still not ideal. 4) A rearra...
by jms2
Sun Apr 21, 2019 6:23 am
Forum: general
Topic: Design a logo for ABug!
Replies: 25
Views: 2369

Re: Design a logo for ABug!

Technically its no problem. You can even have a transparent background. However I would be concerned that the lettering might not show up so well. I might need to add a black outline.
by jms2
Sat Apr 20, 2019 10:09 pm
Forum: general
Topic: Design a logo for ABug!
Replies: 25
Views: 2369

Re: Design a logo for ABug!

I'm on the case...

Still really chuffed that people like the logo. It wasn't even a serious suggestion, but I suppose that's part of its appeal.
by jms2
Fri Apr 12, 2019 4:23 pm
Forum: hardware
Topic: Save my Elk...
Replies: 22
Views: 460

Re: Save my Elk...

Yes, I think so. I would put the JMP at the end of page &FB so that your NOPs don't get messed up by the hardware addresses present in the following pages. It's worth hanging around a bit to get confirmation from someone else first though! Regarding interrupts, there are three kinds - NMI (non maska...
by jms2
Fri Apr 12, 2019 2:48 pm
Forum: hardware
Topic: Save my Elk...
Replies: 22
Views: 460

Re: Save my Elk...

I have not made a NOP-generating ROM before, but I want to suggest an answer to your question (mainly to see if my own understanding is right!): On the Electron OS and BASIC are in one 32k ROM, so that would span the address range from &8000 to &FFFF [that bit I am confident of!] On reset, the 6502 ...
by jms2
Tue Apr 09, 2019 11:49 am
Forum: hardware
Topic: Mysterious Electron Plus4 expansion
Replies: 2
Views: 154

Re: Mysterious Electron Plus4 expansion

I share your sense of intrigue in this! I've got no idea what it is, but the date codes (on the ICs as well as on the rom label) suggest it was made in 1987. One thought is that it was not sold under the name "Plus 4" but as something else. It's professionally made, but not PRES, Slogger or Watford ...
by jms2
Mon Apr 08, 2019 6:48 pm
Forum: software: classic games
Topic: Getting started with Exile...
Replies: 21
Views: 593

Re: Getting started with Exile...

Well done! Yes, it is hard. Not only that, but unlike any other game I've played Exile really has the feeling of being a bitter struggle. That sounds bad, but I thought it was a really good and lifelike feature. You really feel sorry for Finn as he screams in pain from being burned/blown up/shot/bit...
by jms2
Mon Apr 08, 2019 6:44 pm
Forum: introduce yourself
Topic: Acorn Newbie
Replies: 23
Views: 346

Re: Acorn Newbie

I have just cleaned the ULA contacts on my Issue 4 so I'm in a good position to explain how to do it. The ULA is the biggest chip, the one with the metal "X" over it. This X shaped thing is a clip which holds the ULA into a ZIF socket. To release the clip, you need to pick any corner and use a small...
by jms2
Sun Apr 07, 2019 1:09 pm
Forum: programming
Topic: Turbo Elk
Replies: 10
Views: 359

Re: Turbo Elk

Also... as you're clearly interested in this kind of thing, have a look at the attached. This is the Electron Advanced User Guide, which I have been updating a bit in recent years. All the new information has come either from original sources or from the clever people on this forum (I just type it i...
by jms2
Sun Apr 07, 2019 11:57 am
Forum: programming
Topic: Turbo Elk
Replies: 10
Views: 359

Re: Turbo Elk

No problem! :D It's nice to see these old Electron speed-up hacks being dusted off and used again. There is another simple way to speed up the Electron which will work alongside this poke. *FX178,0,0 turns the keyboard scanning off. *FX178,255,0 turns it back on again. I don't know how much this wil...
by jms2
Sun Apr 07, 2019 8:40 am
Forum: programming
Topic: Turbo Elk
Replies: 10
Views: 359

Re: Turbo Elk

I can see what you have done wrong ... put the first poke after the MODE1 command.

The mode change overrides the speed hack as you have written it.
by jms2
Sat Apr 06, 2019 9:08 pm
Forum: programming
Topic: Turbo Elk
Replies: 10
Views: 359

Re: Turbo Elk

Hmm - apart from the typos, I can't see why this wouldn't work. [It should be ?&FE07=&B0 to go faster, ?&FE07=?&282 to revert].
Not tried it myself yet though.
by jms2
Mon Apr 01, 2019 10:11 pm
Forum: community projects
Topic: Acorn Graphics Extension ROM User Guide
Replies: 14
Views: 366

Re: Acorn Graphics Extension ROM User Guide

That looks terrific! It must have taken ages to get it that good!

I may have the card.
by jms2
Mon Mar 25, 2019 8:01 am
Forum: archive requests
Topic: Looking for searchable index of magazines like Electron User and The Micro User
Replies: 2
Views: 117

Re: Looking for searchable index of magazines like Electron User and The Micro User

The Acorn Electron World dvd (and presumably the website as well) contains a full index spread across various HTML files. It would be possible to create something from that I think, but I have not given much thought as to how you could do it. A Python script maybe?
by jms2
Mon Mar 25, 2019 7:57 am
Forum: hardware
Topic: Curious Electron keyboard fault (Iss 4)
Replies: 3
Views: 163

Re: Curious Electron keyboard fault (Iss 4)

Actually, no I didn't! That's a very good point Dave. It won't have been affecting the keyboard, but it might account for some anomalies I'm seeing when testing my E2P board (which is now on a proper PCB) on different Electron configurations.
by jms2
Sun Mar 24, 2019 8:28 pm
Forum: hardware
Topic: Curious Electron keyboard fault (Iss 4)
Replies: 3
Views: 163

Re: Curious Electron keyboard fault (Iss 4)

I took out the ULA and cleaned the contacts with IPA. They didn't look dirty or tarnished at all, but it doesn't matter because cleaning has fixed the problem and the keyboard is now fine. I still can't figure out what the actual failure mode was..! At the same time I used IPA to clean the edge conn...
by jms2
Sat Mar 23, 2019 9:11 pm
Forum: hardware
Topic: Curious Electron keyboard fault (Iss 4)
Replies: 3
Views: 163

Curious Electron keyboard fault (Iss 4)

My issue 4 Electron has suddenly started acting oddly. I know that the solution is likely to be reseating the ULA (something I have never needed to do before), but I thought it might be worth reporting the symptoms in case anyone else sees something similar. All of the following are intermittent, bu...
by jms2
Thu Mar 21, 2019 9:49 pm
Forum: emulators
Topic: What's with some games by Tony Oakden on the Electron?
Replies: 26
Views: 827

Re: What's with some games by Tony Oakden on the Electron?

Does your emulator support direct reading of the keyboard hardware (ie, finding the keyboard status by paging in ROM 10 I think)? That might be a possible cause.
by jms2
Thu Mar 21, 2019 5:43 pm
Forum: hardware
Topic: B+ & Electron MRB Shadow RAM- What’s different?
Replies: 6
Views: 255

Re: B+ & Electron MRB Shadow RAM- What’s different?

Well, of course it's just a marketing name so it doesn't really mean anything. But to an Acorn-using audience circa 1986, the word Master would undoubtedly have a subconscious link to Acorn's newest machine, which just happened to have a superficially similar shadow ram arrangement. I always assumed...
by jms2
Wed Mar 20, 2019 10:35 pm
Forum: emulators
Topic: VIEW Command Mode and Edit Mode
Replies: 6
Views: 188

Re: VIEW Command Mode and Edit Mode

*BASIC is one way out.
by jms2
Wed Mar 20, 2019 8:45 pm
Forum: general
Topic: Maybe Electron User was issuing “fake” news.
Replies: 4
Views: 297

Re: Maybe Electron User was issuing “fake” news.

At first I thought that the new model sounded quite fanciful, but then I noticed the June 1986 date - and realised that the description matches that of the Master Compact quite nicely. I think this is how the "new electron" ended up. Thing is, I don't remember the Compact being in any way cheap. I t...
by jms2
Wed Mar 20, 2019 7:49 pm
Forum: hardware
Topic: B+ & Electron MRB Shadow RAM- What’s different?
Replies: 6
Views: 255

Re: B+ & Electron MRB Shadow RAM- What’s different?

I've been asking myself the same question. What I have come up with so far is this: - The B+ has an addressable latch called the ACCCON register. (Its in the same place as a similar latch on the Master, but has far less functionality. Basically it is just a 1-bit flag). This allows the shadow ram to...
by jms2
Wed Mar 20, 2019 4:30 pm
Forum: programming
Topic: Double Height Charaters issue with Electron Master Ram Board
Replies: 21
Views: 397

Re: Double Height Charaters issue with Electron Master Ram Board

You're completely right:- To summarise, with shadow RAM activated any software whcih directly accesses screen RAM (&3000-&7FFF) does not work but all other legally written software does. My original code memory was being allocated above &3000. Using "DIM" to allocate memory doesn't give you control...
by jms2
Tue Mar 19, 2019 10:59 pm
Forum: programming
Topic: Double Height Charaters issue with Electron Master Ram Board
Replies: 21
Views: 397

Re: Double Height Charaters issue with Electron Master Ram Board

Just make sure the control block is somewhere else, eg in a location below PAGE that you can be confident is free.