pixel artist wanted (for an Enterprise project)

[ssr86]

I don't know if this is the right subforum, but I'm looking for a graphician for an Enterprise 64/128 game I'm currently trying to finish...
The game is a simple arcade-type - look up the minigame "ghost-trick" from "snk vs capcom: match of the millenium" for the neogeo pocket and that's basically what the game is all about. (but with flames instead of the  Red Arremers (?))
Two optional graphic effects, title and options screens to add.
The game mechanics code is more or less finished (although needs some tweaking).
Sprite engine is currently standard-sprites-only but when I enter optimization stage I will probably switch to compiled-sprites for some (or all - if memory allows) animations (especially for the 128k), so the engine will change slightly.
And for that I need the final graphics...
[For standard sprites the actual graphics doesn't make a difference (dimensions aside) speed and memory-wise, but for compressed and compiled sprites it's completely different for all.]

So here I'm asking if there's a person that is willing to help... 

The work to be done is:
- game background screen 168x104 16 color square pixels
- fonts (mainly digits) for the options and game panel (4-color)
- panel background 160x40 4-color
- title screen
- sprite animation (I have my own character sprite but I lack the skills to animate it)

As for the sprite animation - I'm currently using ripped graphics (arthur;P):
- 3 stance animation frames (32x40 pixels)
- 1 jump frame (40x36)
- 2 fall frames (48x31)
- 6 flame frames (16x16)
...but a couple more (2-3?) will be needed...

With my current tempo I think I will still need a couple more months to finish.
After finishing the enterprise version I'll try to port it to the cpc (actually it started as a cpc project but after learning about the enterprise I had to shift).
However with some enterprise-specific features removed.

[MacDeath]

That ?




check at 5:25 :

www.youtube.com/watch?v=Gf8oEG-DlK0

[ssr86]

That ?




check at 5:25 :

www.youtube.com/watch?v=Gf8oEG-DlK0

yeah..., sorry for not including that in my post...

[MacDeath]

feels like a fancy game and wotch game.

So I guess you'll actually use "magnified" pixels, like 2 large pixels in heights... to get big square pixels and actual 160x100 resolution from the 160x200 mode0 equivalent?


BTW you are right to ask at CPC dudes because we know enterprise is a sort of cousin.

sadly i could never understand the colour palette limitations...

can choose 8 colours and the other 8 are mandatory ?

[ssr86]

feels like a fancy game and wotch game.

That's what it actually is.
It was meant to be a simple game that I could actually finish and release... Nothing too fancy.
I wanted to introduce my "character"

So I guess you'll actually use "magnified" pixels, like 2 large pixels in heights... to get big square pixels and actual 160x100 resolution from the 160x200 mode0 equivalent?

Well, why I switched to enterprise is because it has a list controlled display which enables repeating lines of display. So I use a hardware 160x144 "mode0" pixel mode. The cost of this mode is a bigger line parameter list (need one modeline (=16 bytes) per one line of my screen) and the buffer and palette swapping are more time consuming as I need to change the parameters for each line of display in this mode (however this would come in handy if I wanted to get way more colors on the screen - like for the title screen).

For the cpc version I will go with a 160x128 mode0 screen with border between every two lines (don't know how this is called). I wanted to use a kind of dual-line software mode but it would be too slow...

BTW you are right to ask at CPC dudes because we know enterprise is a sort of cousin.

Yeah, the enterprise can emulate the cpc video modes (mode0 with some palette difficulties...), but the main reason would be that the enterprise community is really small, there seems to be only one guy that can do graphics, but he's been silent for over a month, doesn't respond.
And I know the cpc community has a couple of gifted pixelers.
[Next I will try asking the polish atari scene:P I guess]

sadly i could never understand the colour palette limitations...

can choose 8 colours and the other 8 are mandatory ?

In the 16-color mode you can choose the first 8 colors arbitralily from all 256 available.
But the other 8 colors (colors 8-15) are determined by the value of the "fix-bias" register.
There are 32 possible color sets for these 8 colors.
Fix-bias=0 means colors $00,$01,$02,...,$07 (in this order, so mode color 8 is palette color $00,...mode color 15 is palette color $07)
Fix-bias=1 means colors $08,$09,$0a,...,$0f
Fix-bias=2 means colors $10,$11,$12,...,$17
...
Fix-bias=31 means colors $f8,$f9$fa,...,$ff

You can see the full palette here: EP colours

I hate this solution. Really hate it...
It doesn't allow doing full 16-color palette fade effects, no blackening, whitening of the screen via palette (if you're using more than 8 colors that is).
No "dual-playfield mode" like on the cpc...
But I guess there should be some good sides to it... I mean - you change half of the palette with changing only one register value...
But the available combinations feel really limited...

[Puresox]

Just a side related question , where are the best sites to learn about this machine? Just was looking at the Star Sabre Conversion, And it looks as though the machine is more capable than the Amstrad ? Sharper graphics , smoother scrolling etc? I am intrigued.

[Trebmint]

Just a side related question , where are the best sites to learn about this machine? Just was looking at the Star Sabre Conversion, And it looks as though the machine is more capable than the Amstrad ? Sharper graphics , smoother scrolling etc? I am intrigued.

The main site is this. Be warned its mostly Hungarian, but there are some very talented and enthusiastic guys who frequent the English forum. A Very nice machine with a bad keyboard

Enterprise Forever - Index

[Prodatron]

Just a side related question , where are the best sites to learn about this machine?

For technical details this is a good source:
Enterprise Technical Documentation
including the description of the video chip:
Enterprise Technical Documentation: Nick Chip Programmers Guide

And it looks as though the machine is more capable than the Amstrad ?

Yes, the EP could be called an upgraded CPC somehow. Its graphic chip is advanced (including 256 colour mode, each line can have different resolutions and colours, IRQs for each line etc.), it has better memory banking capabilities (like the MSX, PCW, NCxxx) and its OS "EXOS" is much more well-thought-out, compareable to MSX-DOS but still different. It's indeed a very nice machine with a good-looking case. The internal joystick, which is replacing the cursor keys, is quite strange and the keyboard itself unfortunately is cheap (spongy, like this of the Spectrum +). Oh, and you can change the Z80 clock by some modifications to 10MHz, and everything is still working in the usual way but with a faster CPU!

[ssr86]

Just a side related question , where are the best sites to learn about this machine?

apart from the enterpriseforever forum, which Trebmint already mentioned, there is also Enterprise sixty four / one two eight, but there aren't really that many...

Just was looking at the Star Sabre Conversion, And it looks as though the machine is more capable than the Amstrad ? Sharper graphics , smoother scrolling etc? I am intrigued.

I don't know about the sharper graphics...  but it has a pointer based video memory mapping.
This simplifies the scrolling a lot.  You can have a linear screen buffer. 
You can repeat lines of display to get other video resolutions (for example a 96x72 with 256 colors and square pixels mode is possible).
You can also layout the memory like on the cpc.
You can set the left and right screen margins and use this to get some cool screen transition effects (especially if you use more than one modeline for your screen).
2, 4, 16 and 256 color modes are available. 
The 16-color modes suffer a lot from the fix-bias issue...
It has a hires and lores pixel modes - the lores modes use stretched pixels (for example a 4 color lores has pixels like the mode 0, but has 4 pixels per byte, so you save memory).
It has character video modes (however each char uses only 2 colors - an attribute system like on the spectrum?).
Which you can setup to emulate the spectrum display.
You set the palette separately for each modeline, so having a separate modeline for each line of display allows you to get more colors on the screen.

It's memory mapping system is great... There are no fixed configurations to choose from - you choose one which memory segment to use for each 16k area....

Don't know much about the sound capabilities...
It has 3 channels + noise. Only square wave and noise.
Has distortion and ring modulation (guys at ef achieved a "real" sounding distortion guitar instrument with these and all in basic...it uses 2 channels).
It can play 4 channel mods.

It seems that the is-basic is very capable (well I had only a commodore in the past so I think every basic will find every other basic advanced).

Unfortunately nearly all its games are spectrum or amstrad straight ports... so you won't see its potential used...

[MacDeath]

-to put it simply, Enterprise is a well hung arian... 



yeah, those palette "limitations" are a bit strange... this can't enable full use of the awesome  colour full palette easily and you would certainly get some colours that you wouldn't want.

nice to see Enterprise has some dual lines trick, on CPC I think this could be nice but it is actually ressource wastefull, you can more easily display only half the lines, which I call the megabigdark-scanline effect of death.


>>> Back to palette (my real hobby actually)

this colour Bias is somewhat hard to understand to me... would be nice to have some Enterprise palette generator application where you would be able to emulate those palettes accurately... and see what "bias" would do on full 16 inks palette...
Let me check what you said and compare to this colour lookup table... ok

so half of the 16 ink palette would be a pre selected set of 8 inks ordered in a CGA style...
to have Bias on 0 = having mandatory Black, dark red, dark green, somewhat medium/dark blue, dark purple, dark cyan/skyblue, and some bluish grey.


it's half as bad as the 16 colours 320x200 EGA mode with only full CGA palette... but still good because you still have 8 inks to choose properly on a full 256 blue-ish palette (same as MSx2)(or is it green-ish ?).

You have less margin to specialize your whole 16 inks palette, but to be fair on CPC the only 27 colours also are a serious limitation...

Yes may be an advantage for some effects I guess..

You can colour-cycle a whole 8 colours actually... just with one register as you said... as most subpalettes (the bias) are ordered in same way, you can cycle the same sort of sub palette from dark to bright and so on.
If this can get a per line treatment, you may actually get some nice effects, like an horizontal lazer and all things up and down getting colour slided into another shade.
Gotta be investigated...

but I guess to change the 8 free inks and change bias is too CPU demanding to have a fade effect ??

Funny thing : Enterprise doesn't have a lot of actually real true greys... most greys are somewhat coloured...




on the other hand, an Amstrad PLUS is still quite superior concerning graphics, but hey, was released in 1989-1990 so it's like cheating.


what resolution do you have in 256 colours mode ?
extra wide 4x pixels ? (=80 pixels per line ?) or "normal" Mode0 sized pixels ?

Don't know much about the sound capabilities...
It has 3 channels + noise. Only square wave and noise.

Basically it is said to be not that really different than an AY, perhaps a bit better on Sampled sounds though... same AY can also vary actually according to its clocking... Speccy128's AY is....(ouch it hurts) slighty better than CPC's one as it is faster... not even sure AY wouldn't have been quite enough and cheaper on Enterprise...



Please PM me more details about your graphics (style, size and so on) and I'll see If I can be able to deliver or not.
but maybe some more talented dudes may also be interested.

[dcdrac]

hmm a remake of Ghost and Goblins for the CPC would be nice

[ssr86]

You can colour-cycle a whole 8 colours actually... just with one register as you said... as most subpalettes (the bias) are ordered in same way, you can cycle the same sort of sub palette from dark to bright and so on.
If this can get a per line treatment, you may actually get some nice effects, like an horizontal lazer and all things up and down getting colour slided into another shade.
Gotta be investigated...

Well.. to change the fix-bias every line you would have to use a cycle-perfect (maybe not that perfect) code to be able to do that.
If you use intrrupts then you can change fix-bias every two modelines (so every two display lines at most) because an interrupt can be trigerred every second modeline minimum.

but I guess to change the 8 free inks and change bias is too CPU demanding to have a fade effect ??

It depends on how many modelines you have to change in your line parameter table.
For the screen resolution I'm using (160x144 but the play area is 160x104, for the square pixel effect I have one modeline for each line of display) it takes me about 33 cpc nops per mode line I guess (I don't remember real z80 timings and enterprise doesn't have fixed timings because of the video chip, so I count in cpc nops) like below:

Code Select Expand


change_palette:
;; in :
;; de = address of the first modeline inside lpt to swap palette
;; bc = 8*number_of_modelines for color swapping
;; hl = address of 9 byte sequence (fixbias,color0,color1,....,color8)

   ld a,(hl)
   out (fixbias),a
   inc hl

   push hl

swap_colors_in_lpt_loop:

   pop hl
   push hl

   ld a,8
   add a,e
   ld e,a
   adc a,d
   sub e
   ld d,a

   ldi
   ldi
   ldi
   ldi
   ldi
   ldi
   ldi
   ldi

   jp pe,swap_colors_in_lpt_loop

  pop hl
  ret

So it takes me about 3500 cpc nops, so it's not that bad I think...

what resolution do you have in 256 colours mode ?
extra wide 4x pixels ? (=80 pixels per line ?) or "normal" Mode0 sized pixels ?

Extra wide 4x pixels for the 256 modes (or extra 8x wide for the lores 256 mode)

Quote

Don't know much about the sound capabilities...
It has 3 channels + noise. Only square wave and noise.

Basically it is said to be not that really different than an AY, perhaps a bit better on Sampled sounds though... same AY can also vary actually according to its clocking... Speccy128's AY is....(ouch it hurts) slighty better than CPC's one as it is faster... not even sure AY wouldn't have been quite enough and cheaper on Enterprise...

From what I read, the enterprise doesn't have an envelope (but can be emulated in some way), the noise is separate (can't have a square note with some noise like on the ay)...

[Puresox]

For technical details this is a good source:
Enterprise Technical Documentation
including the description of the video chip:
Enterprise Technical Documentation: Nick Chip Programmers Guide
Yes, the EP could be called an upgraded CPC somehow. Its graphic chip is advanced (including 256 colour mode, each line can have different resolutions and colours, IRQs for each line etc.), it has better memory banking capabilities (like the MSX, PCW, NCxxx) and its OS "EXOS" is much more well-thought-out, compareable to MSX-DOS but still different. It's indeed a very nice machine with a good-looking case. The internal joystick, which is replacing the cursor keys, is quite strange and the keyboard itself unfortunately is cheap (spongy, like this of the Spectrum +). Oh, and you can change the Z80 clock by some modifications to 10MHz, and everything is still working in the usual way but with a faster CPU!

Thanks for both replies, really tasty machine , from the little examples I have seen , had it have taken off,fully, I think a real contender . Look forward to delving into it more.

[Prodatron]

Funny thing : Enterprise doesn't have a lot of actually real true greys... most greys are somewhat coloured...

The EP uses a 3bit R, 3bit G and 2bit B palette. It's like the 256 colour mode of the MSX but encoded in a different way (the 2/4/16 colour modes of the MSX are using 512=3R/3G/3B bit colours). So it's "greenish" like you would probably say.
Because of the 2bits for Blue (=4 values) the pure real grey colours are limited to 2 (between complete dark and complete white). But compared to the CPC within the EPs' 256 colour palette you have some other colours which are close to grey.

[MacDeath]

yeah, wasn't sure about the way to twist the 8 bit.

8bits = 2+2+4 bits
8bits = 3 + 3 + 2 bits

can't be really squared...

Actually better solution would quite be to aim at a 5x5x5 RGB cube, but then you use "analog" 5 values RGB cube... and get only 125 colour from perhaps 128 managable... but to me it would be ultimate 8bit palette if 16 colours is the "max"...

wished CPC had such a palette...
but yeah, 4096 is real max in 8 bit standard , more is useless.

[ssr86]

decided to put up a wip video:

enterprise 64/128 - a new mini-game wip - YouTube

please don't mind the used colors - I did only some very quick convertions for use in the prototyping stage...

[Prodatron]

Enterprise graphics can be really great btw!

[Puresox]

Wow they are just stunning for an 8 bit machine , so sharp , are there modes for this machine?

[Prodatron]

decided to put up a wip video:

That looks awesome! You get the feeling, that the EP would be able to do hardware sprites. The screen is 100% full with animations and nice effects at full speed, didn't know that it's possible in this way.

[Prodatron]

Wow they are just stunning for an 8 bit machine , so sharp , are there modes for this machine?

I think they are all generated with Zozosofts EPImgConv tool. Here are other examples (wrong time of the year though ):

Karácsonyi techno muzsika + Enterprise 128 slideshow - YouTube

[arnoldemu]

Today I tried to double the pixels vertically on a plus.
I wasn't successful but I will tweak the timing a bit more when I have time.

The method I used:

1. standard raster interrupts.
2. wait for vsync start
3. HALT (now 2 HSYNCs after start of vsync)
4. Enable DMA channel 0.

DMA channel 0 processes a pause instruction to wait until the first line of the display.
Then 1 interrupt for each line, with a stop/int at the end.

5. Interrupt handler checks if DMA interrupt
6. If it is, it sets the vertical soft scroll. It toggles the value between 0 and &70 after each write:

What should this do?

VCC=0, RC=0, SSCR=0 -> RA output no change (RA output = 0)
VCC=0, RC=1, SSCR=&70 -> RA output (1+7=8 but because only lower 3 bits are output) (RA output=0)
VCC=0, RC=2, SSCR=0 -> RA output no change (RA output = 2)
VCC=0, RC=3, SSCR=&70 -> RA output (3+7=10 but because only lower 3 bits are output) (RA output=2)
VCC=0, RC=4, SSCR=0 -> RA output no change (RA output = 4)
VCC=0, RC=5, SSCR=&70 -> RA output (3+7=12 but because only lower 3 bits are output) (RA output=4)
VCC=0, RC=4, SSCR=0 -> RA output no change (RA output = 6)
VCC=0, RC=5, SSCR=&70 -> RA output (3+7=14 but because only lower 3 bits are output) (RA output=6)

The display is therefore like this:

C000
C000
D000
D000
E000
E000
F000
F000
C050
C050
D050
D050
E050
E050
F050
F050

So going to next line looks a bit like this:

Code Select Expand


ld a,h
add a,&10
ld h,a
ret nc
ld a,l
add a,&50
ld l,a
ld a,h
adc a,&c0
ld h,a
ret


With this method you can change height of screen and vsync position.

This appears to be the only way to do it using soft scroll.

I wanted to use dma interrupts so I can interrupt each line so the code can be used in a game for example.

It almost worked.

I will try again with it, perhaps I can make it work next time.

[andycadley]

Hmm, interesting idea. It definitely seems like something that should work in theory.

[MacDeath]

in what order does the Amstrad display lines on Monitor ?

Would some 25hz alternance of the same half lines pixels but with one line difference work ? would get flipping between lines and black lines and be messy I guess.

[TotO]

Today I tried to double the pixels vertically on a plus.
I wasn't successful but I will tweak the timing a bit more when I have time.

Try on CPC with PlayCity so... 

[MacDeath]

Try on CPC with PlayCity so..

tell us more about that then...

Also I like the way this thread just slided from "Help me to mockup some pixels." into "how the hell can we do that Enterprise Trick on the good old CPC?"...