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http://www.retrosoftware.co.uk/forum/viewtopic.php?f=23&t=164		 Page 1 of 1
Author:  ThomasHarte [ Mon Aug 04, 2008 7:45 pm ]
Post subject:  Hi
Just a short message to say 'hi'. Ummm, I wrote the ElectrEm Acorn Electron emulator (and am still writing it, though more slowly than I once was), I'm working on an OpenGL version of Freescape that plays original Construction Kit projects with no modification and I am also having a fairly decent stab at vector 3d on the Sam Coupé.

I guess I'm offering small-scale programming help rather than the ability to lead any particular project. I'm pretty good on the Electron hardware, currently great on any "how did they do that" questions about Freescape and not awful at z80 and 6502 assembly.

If anybody wants to do any sort of peculiar pseudo-emulation projects (e.g. write a game for the BBC, release it simultaneously as a PC title by running the same code but trapping your graphics routines and branching them out to OpenGL/whatever) then that's probably exactly my sort of thing.

Vanity youtube links:
ElectrEm running Chuckie Egg
Phantasma (my OpenGL Freescape) running the 8bit demo game reasonably well
A little demonstration of my Sam Coupe 3d code
Author:  SteveO [ Tue Aug 05, 2008 8:23 am ]
Post subject:  Re: Hi
Your Sam Coupe work looks really great, so smooth.
Author:  Samwise [ Tue Aug 05, 2008 9:23 am ]
Post subject:  Re: Hi
Hi, Thomas.

I've changed that bit of text on the wiki when you're logged out, from Login / Create Account to Wiki Login, and also stopped it hiding behind the search bar. Hopefully, that should reduce confusion.

The only dedicated Electron project we atm is The Fisherman's Quest. Unfortunately, there've been no updates since late March, so I'm not sure what the latest is on that.

Sam.
Author:  ThomasHarte [ Wed Aug 06, 2008 9:44 am ]
Post subject:  Re: Hi
SteveO wrote:
Your Sam Coupe work looks really great, so smooth.

Once I've done as much as I think I can with it, it'll be open source. Even as it stands it'd fit inside a 128k machine though you'd get a speed drop if you had to arrange things so that the first 2kb of memory space wasn't RAM. It uses ye olde f(x) = (x^2)/4 lookup table method for 2.8 fixed point multiplies, but centres the table around memory address 0 to save on lookup costs.
Samwise wrote:
Hi, Thomas.

I've changed that bit of text on the wiki when you're logged out, from Login / Create Account to Wiki Login, and also stopped it hiding behind the search bar. Hopefully, that should reduce confusion.

Oh, I'm sure I was just being stupid. I probably should have waited until I got home to try to sign up, as obviously I can only really do internet stuff either quickly or not at all while at work.
Samwise wrote:
The only dedicated Electron project we atm is The Fisherman's Quest. Unfortunately, there've been no updates since late March, so I'm not sure what the latest is on that.

I think it'd be neat to use the Firetrack smooth scrolling trick to do something, just so that there's more than one smooth scrolling game for the thing. But I don't really know where I'd start. If I get a chance then I think I'm going to look into writing either a DFS -> UEF converter or adding a UEF output option to BeebASM, since although you can use DFS disks on an Electron, it isn't the default filing system and many people don't even have disk drives.
Author:  Samwise [ Wed Aug 06, 2008 10:29 am ]
Post subject:  Re: Hi
ThomasHarte wrote:
Oh, I'm sure I was just being stupid.

No, no - that was useful feedback. I was aware of the CSS screw-up with the text hiding-behind the search bar, but I was being lazy not fixing it - you don't see it if you set your cookies to keep you permanently logged in. Changing the text hadn't occurred to me - but it was misleading, so that's good too.

ThomasHarte wrote:
If I get a chance then I think I'm going to look into writing either a DFS -> UEF converter or adding a UEF output option to BeebASM, since although you can use DFS disks on an Electron, it isn't the default filing system and many people don't even have disk drives.

I think that's a cracking idea! I guess when you've achieved one, it wouldn't be hard to do the other. And, as I started on an unexpanded Electron, I agree entirely - the Electron was a cassette machine, and shouldn't have anything to do with this new-fangled disk nonsense ... :)

Sam.
Author:  ThomasHarte [ Wed Aug 06, 2008 5:54 pm ]
Post subject:  Re: Hi
I should also say that I'm more than happy to help others with 6502 3d stuff if they'd like it. Much of the z80 stuff is equally applicable to the 6502 in algorithm terms.

Incidentally, re: Electron software, how much would it cost to manufacture a game on ROM nowadays? I'm guessing still prohibitively much?
Author:  AndrewW [ Wed Aug 06, 2008 8:08 pm ]
Post subject:  Re: Hi
3D - like planet surfaces for an Elite add-on?:
viewtopic.php?f=20&t=78
Author:  DaveF [ Wed Aug 06, 2008 8:09 pm ]
Post subject:  Re: Hi
ThomasHarte wrote:
Incidentally, re: Electron software, how much would it cost to manufacture a game on ROM nowadays? I'm guessing still prohibitively much?


Considering the amount you'd probably sell, I'd say it's doable ;-)

Welcome to the forums BTW. Nice Sam Coupe stuff, never even heard of the machine before!
Author:  ThomasHarte [ Thu Aug 07, 2008 12:39 pm ]
Post subject:  Re: Hi
AndrewW wrote:
3D - like planet surfaces for an Elite add-on?:
viewtopic.php?f=20&t=78

I think the main technical issue with that would be precision. It's expensive to use a number format that can simultaneously hold the positions of things on a planet and things in space and it's expensive to store things in separate levels of precision and then intermingle them at runtime. If you look at other games that came out at about the same time as Frontier, such as Battlecruiser 3000, you'll see that they usually cheat by cutting from navigation in space to navigation near the surface. Being able to do a seamless in-engine transition is very difficult with the sort of data formats that typify older hardware. I wouldn't be surprised if you had to drop to Northern Star/Southern Belle-type framerates.
DaveF wrote:
ThomasHarte wrote:
Incidentally, re: Electron software, how much would it cost to manufacture a game on ROM nowadays? I'm guessing still prohibitively much?


Considering the amount you'd probably sell, I'd say it's doable ;-)

Welcome to the forums BTW. Nice Sam Coupe stuff, never even heard of the machine before!

For practical game programming purposes, the Sam is just a Spectrum with a 4bit colour mode, a CPU that is about 14% faster* and more memory. But a really awkward paging scheme.

* yes: four times as much video data, 14% more time to process it all. Somehow the machine never took off...

The neat thing about a ROM title is that it'd run at 2Mhz, at least double any code loaded from tape or disk. And the extra memory would be a benefit. That is, unless you went the extremely lazy Acornsoft route and just used the ROM filing system so that the code is sitting in ROM where it could be executed quite quickly but is copied to RAM and executed slowly just so that nobody needs to re-assemble anything, of course.

I guess the main disadvantage - apart from production cost - is that you're requiring that the user have an add-on that can take ROMs. I guess you could produce a bit of hardware that plugged straight into the expansion port, but adding new hardware isn't exactly inkeeping with producing games for old platforms.
Author:  ParasS [ Thu Aug 07, 2008 12:43 pm ]
Post subject:  Re: Hi
I presume you chaps really mean EPROM rather than ROM - which you can get the kit (eraser/blower) for quite readily I would suggest, along with older 27128 type chips coming up on eBay all the time I'm sure.
Author:  CMcDougall [ Thu Aug 07, 2008 3:46 pm ]
Post subject:  Re: Hi
ThomasHarte wrote:
it isn't the default filing system and many people don't even have disk drives.


it is for me, plenty 31/2" PC disc drives floating about :D

ACP'87 Advanced 1770 DFS 2.00 works for the Plus3.

i put ADFS1.00 in the bucket where it belongs :evil:

see STH hardware -Plus3 Question ;)
Author:  ThomasHarte [ Thu Aug 07, 2008 5:56 pm ]
Post subject:  Re: Hi
CMcDougall wrote:
ThomasHarte wrote:
it isn't the default filing system and many people don't even have disk drives.


it is for me, plenty 31/2" PC disc drives floating about :D

ACP'87 Advanced 1770 DFS 2.00 works for the Plus3.

i put ADFS1.00 in the bucket where it belongs :evil:

see STH hardware -Plus3 Question ;)

Hang on, you opted to halve your disk storage abilities? I would have thought an &E00 ADFS, or at least one with MLOAD/MRUN would be the way forward if you were in a position to be able to pick any of them.

I think I'm right in saying that the original ADFS v1.00 ROM is the only one to have hard disk support built in. I always meant to investigate that properly for ElectrEm, but never have.
Author:  AndrewW [ Thu Aug 07, 2008 7:14 pm ]
Post subject:  Re: Hi
ThomasHarte wrote:
AndrewW wrote:
3D - like planet surfaces for an Elite add-on?:
viewtopic.php?f=20&t=78

I think the main technical issue with that would be precision. It's expensive to use a number format that can simultaneously hold the positions of things on a planet and things in space and it's expensive to store things in separate levels of precision and then intermingle them at runtime. If you look at other games that came out at about the same time as Frontier, such as Battlecruiser 3000, you'll see that they usually cheat by cutting from navigation in space to navigation near the surface. Being able to do a seamless in-engine transition is very difficult with the sort of data formats that typify older hardware. I wouldn't be surprised if you had to drop to Northern Star/Southern Belle-type framerates.


Thomas - if you're interested, this discussion is moved here:

viewtopic.php?f=20&t=78&p=1226#p1226
Author:  CMcDougall [ Fri Aug 08, 2008 9:39 am ]
Post subject:  Re: Hi
ThomasHarte wrote:
Hang on, you opted to halve your disk storage abilities? I would have thought an &E00 ADFS, or at least one with MLOAD/MRUN would be the way forward if you were in a position to be able to pick any of them.


ADFS 1.00 puts PAGE& upto 1D00, DFS goes to 1900 by default, but can easily put further down to 1100. Then use 'mem move' progs IF need be.

see ere http://www.stairwaytohell.com/sthforums ... f=3&t=1543

&E00 ADFS & DFS dont work in a Plus3, only a Plus1 cart system with ACP cards ;)
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