AGD converted games - BIGPACKs v2.6

Use this forum to submit new files for the download section of the archive. I will check each submission and upload it to the archive on a regular basis.
Post Reply
pser1
Posts: 1434
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

AGD converted games - BIGPACKs v2.6

Post by pser1 »

Hello,
to help users keep the collection together, I am uploading here a zip whith the whole colection, say 219 games
for each machine and both versions, short and long names
cheers
pere
Attachments
DRAGON-BIGPACK SHORT NAMES V2.6.ZIP
(6.09 MiB) Downloaded 315 times
DRAGON-BIGPACK LONG NAMES V2.6.ZIP
(6.1 MiB) Downloaded 302 times
COCO-BIGPACK SHORT NAMES V2.6.ZIP
(4.92 MiB) Downloaded 325 times
COCO-BIGPACK LONG NAMES V2.6.ZIP
(4.93 MiB) Downloaded 308 times
lcurtisboyle
Posts: 10
Joined: Thu Nov 05, 2020 9:47 pm

Re: AGD converted games - BIGPACKs v2.6

Post by lcurtisboyle »

Pere - I am trying to convert a Spectrum graphic to a PMODE 4 Dragon/Coco style graphic. I have the interlacing, etc. stuff all figured out fine, but I am finding that the image I am working with seems to switch which bits are black or white depending on which 8x8 tile it is, and I am trying to figure out a rhyme or reason to it. Would it be based on the colors in the attribute section (the last 768 bytes of the Spectrum graphics file), and, if so, how would that be done. From what I see, some tiles are fine, and others are inversed from what they should be (for a black and white image with the tile colors stripped.
User avatar
robcfg
Posts: 1359
Joined: Sat Apr 04, 2009 10:16 pm
Location: Stockholm, Sweden

Re: AGD converted games - BIGPACKs v2.6

Post by robcfg »

Sadly it has to be done manually, as I did with the screens of Aeon.

That said, I can help you if you like to.
User avatar
robcfg
Posts: 1359
Joined: Sat Apr 04, 2009 10:16 pm
Location: Stockholm, Sweden

Re: AGD converted games - BIGPACKs v2.6

Post by robcfg »

I remembered why some tiles appear to negative.

The bitmap part indicates where the foreground colour and the background colour go inside every 8x8 tile.

But there’s no restriction on what colour is the foreground one or the background one, so without the colour information, the bitmap image can make little sense, as you’ve already seen.

So, what I do is I take the original Spectrum image and then export it to png and from there to Gimp. There I convert it to b/w and add some dithering.
pser1
Posts: 1434
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

Re: AGD converted games - BIGPACKs v2.6

Post by pser1 »

lcurtisboyle wrote: Mon Jun 14, 2021 12:02 am Pere - I am trying to convert a Spectrum graphic to a PMODE 4 Dragon/Coco style graphic. I have the interlacing, etc. stuff all figured out fine, but I am finding that the image I am working with seems to switch which bits are black or white depending on which 8x8 tile it is, and I am trying to figure out a rhyme or reason to it. Would it be based on the colors in the attribute section (the last 768 bytes of the Spectrum graphics file), and, if so, how would that be done. From what I see, some tiles are fine, and others are inversed from what they should be (for a black and white image with the tile colors stripped.
Hello!
if you just want to convert a fixed image, it would be enough to 'cut' the Spectrum graphic file stripping out the attribute zone and converting
it into a binary file just adding the header (and trailer for CoCo)
I made a small std C app that does the cutting part. The rest is just copy together fixed chunks
I attach it here for maybe it could be of use for you. The zip contains a windows executable and the source file
Besides I have added a bat file that shows how to use it (in my environment ...)
cheers!
pere
Cutter.zip
(16.96 KiB) Downloaded 48 times
User avatar
robcfg
Posts: 1359
Joined: Sat Apr 04, 2009 10:16 pm
Location: Stockholm, Sweden

Re: AGD converted games - BIGPACKs v2.6

Post by robcfg »

But that generates the problem he’s describing.

It should be easy to do a tool that recreates the original Spectrum image with the right colours, convert it to black and white, and save it.
pser1
Posts: 1434
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

Re: AGD converted games - BIGPACKs v2.6

Post by pser1 »

robcfg wrote: Tue Jun 15, 2021 10:55 am But that generates the problem he’s describing.
It should be easy to do a tool that recreates the original Spectrum image with the right colours, convert it to black and white, and save it.
Hello Robert,
All of the AGD games that had an intro screen have been converted the way I have described.
This works perfectly for the PAL Dragons and CoCos
In case you need to run it on a Tano or NTSC CoCo you know that there are big chances for the artifacted colours to appear
The Spectrum resolution is 256x192. If we apply this to a NTSC PMode4 we know it is going to be shown as 128x192 and artifacts
will show up immediately. If this is the case, then there is no other way than manually edit it :-(
cheers!
pere

Ps In artifacted mode we know that every two bits determine the colour of a pixel, so 00, 01, 10, 11 will result in the B/W and the
two additional artifacted colours
User avatar
robcfg
Posts: 1359
Joined: Sat Apr 04, 2009 10:16 pm
Location: Stockholm, Sweden

Re: AGD converted games - BIGPACKs v2.6

Post by robcfg »

My point is that if you only take the bitmap memory, you don’t get a good image because you can have one color as foreground color on one tile and as background color on the next one, creating the ‘negative squares’ problem.

As I said, it should be easy to create a more consistent result by translating the Spectrum bitmap+attribute memory into a regular image and then converting and dithering it into black and white for the Dragon.

Can you send me a Spectrum image, with its attributes so I can take a look at it?
lcurtisboyle
Posts: 10
Joined: Thu Nov 05, 2020 9:47 pm

Re: AGD converted games - BIGPACKs v2.6

Post by lcurtisboyle »

robcfg - your last post described what I was encountering (tiles swapping foreground / background for the same colours on a whim). I changed my converter to allow one to manually select specific tiles to invert, which allowed me to fix the one I was working on (mostly). Unfortunately the project I was doing it for turns out doesn't have enough disk space to always fit a PMODE 4 style graphic, so I stopped working on the "cleanup" phase that Pere was mentioning. But thanks everyone for the help!
Post Reply