Search found 129 matches

by Kevin Edwards
Mon Sep 30, 2019 6:18 pm
Forum: programming
Topic: Kevin Edwards assembler series in Micro User
Replies: 15
Views: 3148

Re: Kevin Edwards assembler series in Micro User

Awesome!

Many thanks, Chris!
by Kevin Edwards
Thu Sep 19, 2019 10:03 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

Yes, I always had a bit of fun filling those free page boundry bytes with messages for friends and hackers alike.

"Hi BTW"

That's for a good friend of mine, 'Boris The Wombat'.
by Kevin Edwards
Wed Sep 18, 2019 9:07 pm
Forum: software: classic games
Topic: Nightshade protection [technical]
Replies: 168
Views: 55481

Re: Nightshade protection [technical]

Cool. Glad it loaded OK.

Here's my original set of tapes - both never used!
DSC_0143_small.jpg
by Kevin Edwards
Wed Sep 18, 2019 9:01 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

I must admit I can't remember anything about the Stryker's Run protection. Sounds like it only had a single decoder and some filename mangling - something I didn't usually do.
by Kevin Edwards
Wed Sep 18, 2019 7:40 pm
Forum: software: classic games
Topic: Nightshade protection [technical]
Replies: 168
Views: 55481

Re: Nightshade protection [technical]

Does it run OK?
by Kevin Edwards
Wed Sep 18, 2019 7:38 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

From what I have been told, the people that tried seriously to hack my protection resorted to using some kind of modified OS ROM and/or hardware device. Some were successful, but most failed. Having multiple decoders made it a hard slog - especially when you reached the end and found out that it had...
by Kevin Edwards
Mon Sep 16, 2019 5:58 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

To be fair, the work I did for the Superior Software disk system wasn't really about protection, but making the disks dual-format instead - ie it would load on 40 or 80 track drives so there was no need to sell two disk versions. In terms of decoders, encryption etc, there was very little indeed so ...
by Kevin Edwards
Sun Sep 15, 2019 9:13 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

I decided to drop the continuous stream loader as I had some feedback that it was problematic for some people and not very user-friendly when load-errors occured. I think I only used it about four times ( Knight Lore, Alien 8, Lunar Jetman and Nightshade ?). Bit of a guess with those titles to be ho...
by Kevin Edwards
Sun Sep 15, 2019 9:07 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

I generally dedicated more time to games written by fellow school friends - Paul Proctor ( who wrote most of the Ultimate Play the Game titles ) and Chris Roberts ( Wizadore, Match Day, Stryker's Run ). When time was tight, and a quick turn-around was required, a more simplistic protection system wo...
by Kevin Edwards
Sun Sep 15, 2019 7:50 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Re: Game software protection list ( Kevin Edwards )

Hi Rich, IIRC I developed B+/Master friendly versions of the en/decoders that didn't include any ROM address references. Can't remember if i used them for certain on Stryker's Run or if I fell back on 'simplistic' decoders. The story behind Star Clash is more interesting. Basically, I was approached...
by Kevin Edwards
Sun Sep 15, 2019 7:36 pm
Forum: adventures
Topic: Search for the Lost Orb
Replies: 20
Views: 2823

Re: Search for the Lost Orb

Thank you for your hard-work. Sorry I couldn't provide any more information. It looks like the author will remain a mystery!
by Kevin Edwards
Sun Sep 15, 2019 7:17 pm
Forum: software: classic games
Topic: Game software protection list ( Kevin Edwards )
Replies: 32
Views: 1102

Game software protection list ( Kevin Edwards )

Hi, I recently started compiling a list of BBC Micro and Electron games that I protected - TAPE versions. I've reached the point where I think it's almost complete but have, no doubt, forgotten a few. I did this work 30 to 35 years ago and my memory is not as good as it once was. I would be very gra...
by Kevin Edwards
Tue Apr 09, 2019 1:22 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

I uploaded a video of Lunar Jetman being assembled from the original source code - only 9 bytes free!

https://www.youtube.com/watch?v=Eh6lgIx5By0
LJASM2.jpg
by Kevin Edwards
Sun Mar 03, 2019 9:48 pm
Forum: software: classic games
Topic: Galaforce BBC Micro 6502 source code now available
Replies: 4
Views: 950

Galaforce BBC Micro 6502 source code now available

Hi, I have just released the 6502 source code for my BBC Micro game, Galaforce, from 1986. This was taken from the original master disks and adapted to build using BeebAsm on a PC. I hope this gives some insight into how games were made in the 1980s! You can find the details on my Twitter account:- ...
by Kevin Edwards
Fri Feb 08, 2019 7:51 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

It's quite amazing how I still remember most of this code from over 33 years ago - written when i was only 19. I wish my memory was as good now as it was then!

So BeebEM appears to have some issues with its 6522 TIMER emulation? I guess it's based on a very different code-base than b-em?

Kevin.
by Kevin Edwards
Thu Feb 07, 2019 11:24 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

Here's one of mine using the original code:-
LJRUN2.png
by Kevin Edwards
Thu Feb 07, 2019 11:20 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

Ah! Jolly good, it does get past all the protection.

What are those solid squares? They don't look right.
by Kevin Edwards
Thu Feb 07, 2019 10:59 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

The blockless 1200 baud data streams I used did put a lot of people off as they couldn't be loaded using the normal tape filing system. I did try to use faster baud rates, but I seem to remember the Serial ACIA 6850? wouldn't allow faster speeds for the tape system. So, are all the Beeb emulators un...
by Kevin Edwards
Thu Feb 07, 2019 8:42 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

Many thanks Diminished for grabbing, and going through that code. Yes, that all looks rather familiar. I'd almost forgotten about the REPLAY check. I think they released a later version of the device / software to get around my checks. I can see all the tricks I expected in there:- 1.) Stashing impo...
by Kevin Edwards
Wed Feb 06, 2019 3:35 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

How weird. I never noticed that before.

I wonder if it's because it uses 'offset' assembly and assembles the object code into sideways RAM. It looks like it's reading from the BASIC ROM?
by Kevin Edwards
Wed Feb 06, 2019 3:02 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

If you would like to see BBC Micro Lunar Jetman assembling from original source code this may be of interest:-

[ VIDEO on YouTube ]

https://www.youtube.com/watch?v=Eh6lgIx5By0&fe=


[ Screen Grabs ]
LJ_GRAB1.JPG
LJASM2.jpg
by Kevin Edwards
Wed Feb 06, 2019 2:49 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

I have dug out the original source code master disks for Nightshade and Lunar Jetman ( Paul Proctor's original disks ) They confirm that LunarJetman was finished around 27/9/1985. DSC_0255.JPG and Nightshade was finished around 16/10/1985 DSC_0256 - Copy.JPG Still not sure of the official release da...
by Kevin Edwards
Wed Feb 06, 2019 2:09 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

That fragment is part of the IRQ code, so the LDA &FC was just the start of the postamble, to restore A before doing RTI. OK. In that context the &FC access make total sense. The LDA &102,X grabs part of the return address from the stack and re-seeds the VIA timer just to make emulation / hacking e...
by Kevin Edwards
Wed Feb 06, 2019 9:32 am
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

Hi Rich, I can't recall all of the detail as it was so long ago, but i'm guessing it was kind of 'mis-direction'. I wish I still had the source code! Without the correct values being read the de-cryption would produce incorrect results so i'm assuming it wasn't a bug and executed as intended, howeve...
by Kevin Edwards
Tue Feb 05, 2019 8:40 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Re: Lunar Jetman protection

Cool. Thanks for posting the various images. It was quite common practice for me to make use of previously 'stashed' values in later stages of the protection. I would quite often put these values in volatile areas of memory that would get trashed is someone was breaking into the code via the BASIC i...
by Kevin Edwards
Tue Feb 05, 2019 1:14 pm
Forum: software: classic games
Topic: Lunar Jetman protection
Replies: 39
Views: 2122

Lunar Jetman protection

Hi, Following on from the Nightshade protection thread , did anyone manage to crack Lunar Jetman and put it on disk? I remember it having some quite nasty protection, but can't remember if it was quite as painful as Nightshade's. In fact, I can't remember which title was released first - i'm assumin...
by Kevin Edwards
Mon Nov 26, 2018 12:35 pm
Forum: software: other
Topic: Source code for OS1.2, BBC Basic and other Acorn software
Replies: 6
Views: 966

Re: Source code for OS1.2, BBC Basic and other Acorn software

Many thanks, Jonathan for the extra links - and for the magnificent work you have done on your site! The BasPlus code is really interesting - part of that looks very similar to the code I saw back in the late 80s. Time for a good browse through it all. Did you re-create the 8-bit basic source code v...
by Kevin Edwards
Sun Nov 25, 2018 7:08 pm
Forum: software: other
Topic: Source code for OS1.2, BBC Basic and other Acorn software
Replies: 6
Views: 966

Re: Source code for OS1.2, BBC Basic and other Acorn software

Thanks for the links. The JGH annotated BBC Basic dissassemblies are great. A lot of effort has been put into the creation of those images! Still got my fingers crossed that someone has the original ones by Sophie. Possibly an ex-Acorn staff member or 'friends-of' Acorn staff have copies. I think I ...
by Kevin Edwards
Sun Nov 25, 2018 3:49 pm
Forum: software: other
Topic: Source code for OS1.2, BBC Basic and other Acorn software
Replies: 6
Views: 966

Source code for OS1.2, BBC Basic and other Acorn software

Hi, I was wondering if anyone has any original Acorn / Acornsoft source code for the BBC Micro and Electron - BBC Basic and OS in particular. I seem to remember having a conversation with someone many years ago and them mentioning that OS1.2 and Basic 2 / IV source had been preserved. I'm sure they ...
by Kevin Edwards
Sun Nov 11, 2018 12:42 pm
Forum: software: classic games
Topic: Crazee Rider 6502 source code now available
Replies: 11
Views: 1313

Re: Crazee Rider 6502 source code now available

Hi, I have updated the BBC Micro Crazee Rider source code archive to include the original source code disk image ( .dsd ). The latest update information can be found here:- https://twitter.com/KevEdwardsRetro The repository now contains the original BBC BASIC tokenised source code files that can be ...