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Author Topic: Tetripac on the C7420 module  (Read 7969 times)
partyicebear
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Retro time


« on: July 26, 2014, 09:29:17 AM »

Before I share my experience of developing a game with the C7420 module I would like to introduce myself.

I got a VP G7400 together with a C7420 module and two games (Pickaxe Pete and Munchkin) from my parents when I was 14 (for like 500 swiss francs which was a huge amount at that time). In Liechtenstein, where I grew up, this game system was not as popular as Atari or Intv though, so I didn't have the chance to play many games.

Soon I was thrilled by the opportunity of being able to creatively develop my own programs. The C7420 was my inspiration to move on to my next home computer, an Amstrad CPC6128 (not the mainstream C64) which gave me insight to more kind of applications (Multiplan, WordStar) and programming languages (Pascal) in addition to some cool games ("Who dares wins", "Elite", "Sorcery+", "Tomahawk", etc.) I bought.

About one year ago I was reminded of those roots when my good old piece re-appeared in the basement of my parents. That made me wonder and I came across this forum where you guys provide so many fantastic stories. I’ve never believed in finding so many minded people after 30 years of the launch of this system. And in addition to that even more fans are coming up (eg. the amazing VectrexRoli).

So I decided to dive into this world of the C7420 and try to develop my own simple version of Tetris.  I have attached the .dat file (for the emulator) and the .mp3 file (for the device) and I also made a short movie:
YouTube: http://www.youtube.com/watch?v=Zf5fYxIqot0

My experience:
  • Developing with the 02EM emulator works very well because it’s very stable and the programs are loaded/saved fast.
  • The BASIC instruction set was good enough for this game although some features are missing (limited line length, missing ‘else' branches, no definite long variable names, no relative cursor moves, graphics/sprites/sound limitations).
    Still there is a lot of fun programming and being able to quickly make progress with this easy programming language.
  • The biggest challenge is to find both a performant and a memory saving way.
    So I had to reuse a lot of code and had to avoid using multi-dimensional arrays/loops, abstract programming with data reading, high line numbers and lots of comments.
  • The CPU is rather quickly at executing simple operations compared to other Z80 systems (MSX, CPC).
  • The game runs faster on the device than on the emulator which is better than the other way around.

Next I would like to learn more about the machine code subroutines. Maybe there are some 'simple' features that improve the game in terms of pace, features and memory.
 
Of course I would be very happy if many of you contributed to relaunch the activities on the C7420 module.

At the end I wanna thank René and Marc who supported me a lot  Smiley

Gerd
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Rafael
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« Reply #1 on: July 26, 2014, 02:43:35 PM »

Hey  Cheesy
What nice surprise! I´ll play it now, thanks for that Wink
C7420 game library is growing.
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gertk
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« Reply #2 on: July 27, 2014, 10:48:00 AM »

Hi Gerd,

Looks good, speed is also quite good.
How about different colors for the blocks ?
Is this pure basic ?

I did a snake game and a fellswoop clone in c7420 basic. Development was on my workstation under Linux and I used a small program to convert labels into line numbers so it made a lot easier to edit the code. The converter program then made it into line numbered code for use with the emulator, or a binary blob to put on the sdcard of my c7420 emulator for the 7400

http://videopac.nl/forum/index.php?topic=1713.0



Gert

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partyicebear
Trying to get the cartridge in...
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Retro time


« Reply #3 on: July 27, 2014, 10:34:42 PM »

Thanks for your motivating feedbacks  Smiley

Blocks color is on scope in the next version for sure. As I have run out of memory because of coding everything in BASIC I had to pass on that for now (a pity CLEAR 50,-2 does not work on the device).

Thanks for the link to the snake program, I'll try it, and yes, a BASIC "SDK light" would help to improve the development efficiency a lot. I did work mostly with the simple WIN editor.

Is the Fellswoop clone available anywhere resp. did you also work on Snafu, pipepanic or space invaders?

I would appreciate it to have a reference list with all C7420 games and apps so that anyone (new to it) can have a quick & easy access. I could start with collecting the ones mentioned in this forum.
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gertk
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« Reply #4 on: July 28, 2014, 07:42:36 AM »

Thanks for your motivating feedbacks  Smiley

Blocks color is on scope in the next version for sure. As I have run out of memory because of coding everything in BASIC I had to pass on that for now (a pity CLEAR 50,-2 does not work on the device).

I guess most of the C7420 in the wild have only 16k of memory, Rene has modified his C7420 to have 32k but the system does not recognize this automatically.

Quote
Thanks for the link to the snake program, I'll try it, and yes, a BASIC "SDK light" would help to improve the development efficiency a lot. I did work mostly with the simple WIN editor.

Editing and entering a program on a G7400 is a real pain (literally because of the keyboard...). A Basic SDK would be nice but a good editor and converter on a PC do wonders. With my converter program you can add lots of comments around the code and if it is not preceeded by a REM statement it will not take up space in the output program.

Quote
Is the Fellswoop clone available anywhere resp. did you also work on Snafu, pipepanic or space invaders?

SwellFoop (latest version is near the end)
http://videopac.nl/forum/index.php?topic=1852.0


Snafu was on the todo list, I started with PipePanic but the algorithm is quite complex so I did not finish it. Space Invaders was a mere proof of concept that you can use the user-defined-characters for animation and movement by carefully precalculating all variations of the invaders. I did not go further with it.

Some info on space invaders (source is in the first post)
http://videopac.nl/forum/index.php?topic=1632.0

Quote
I would appreciate it to have a reference list with all C7420 games and apps so that anyone (new to it) can have a quick & easy access. I could start with collecting the ones mentioned in this forum.
« Last Edit: July 28, 2014, 07:56:30 AM by gertk » Logged

>>G7000 G7200(P+S) G7400 N60 JET27 VG5000 ZX80 ZX81 ORIC-1 COMX35 Aquarius<<
Rafael
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« Reply #5 on: October 16, 2014, 12:22:19 AM »

Hi Partyicebear,

Today, playing Tetripac, I founded a bug. I never noticed before. But in figure you´ll see a piece (an yellow arrow is pointing it) that not completed it´s trajectory.
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partyicebear
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Retro time


« Reply #6 on: January 03, 2015, 12:18:05 AM »

First of all I wish you all the best for 2015 and the same passion for this forum as in the last year  Smiley

During the last free days I had some time to work on a new version of TETRIPAC.
Now it contains coloured shapes and fixes some bugs as mentioned abouve (thanks for the hint).

I attached the new .dat file for the emulator and the .mp3 file for the module.
And here is a short glimpse how it looks like:
YouTube: http://www.youtube.com/watch?v=spTN-wr4WQo

I'm happy to get more hints and ideas to improve this game or launch another project on the C7420 BASIC module.
« Last Edit: January 03, 2015, 12:23:53 AM by partyicebear » Logged
Rafael
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« Reply #7 on: May 23, 2015, 02:02:57 PM »

Thanks by share this, Party Smiley
The new version with colored shapes is great. I played it sometimes and seems the bug disaperead.
You and Gert are making the C7420 really fun, thanks!
« Last Edit: May 23, 2015, 11:57:58 PM by Rafael » Logged
partyicebear
Trying to get the cartridge in...
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Posts: 32

Retro time


« Reply #8 on: May 25, 2015, 12:03:07 AM »

Thanks for your feedback, Rafael  Smiley

I thought that's the first tetris kind a game on VP until I realized some weeks ago that PPP (puzzle piece panic) had nicely realized it before  Cheesy
Now I've started working on a new traditional game and hope to be the first one  Roll Eyes
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Rafael
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« Reply #9 on: May 31, 2015, 08:24:59 PM »

Thanks for your feedback, Rafael  Smiley

I thought that's the first tetris kind a game on VP until I realized some weeks ago that PPP (puzzle piece panic) had nicely realized it before  Cheesy
Now I've started working on a new traditional game and hope to be the first one  Roll Eyes

That´s not a problem, now we can play Tetris with O2 and also with C7420 module. C7420 is lacking of games, so new games are ever welcome. Nice to know you´re working something new Smiley
I hope sometime to try something with  C7420, too Smiley
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Rene_G7400
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« Reply #10 on: June 01, 2015, 09:07:15 AM »

C7420 is lacking of games, so new games are ever welcome. Nice to know you´re working something new Smiley
I hope sometime to try something with  C7420, too Smiley

Yes, more games for the C7420 would be nice, but I wonder how many Videopac collectors own a C7420 and know how to use it?
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ptol
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« Reply #11 on: June 01, 2015, 05:26:22 PM »

I have one, never used it though  Smiley
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TomBeck
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« Reply #12 on: June 01, 2015, 07:22:42 PM »

Me too.  Sad

New C7420 + some Philips Data Recorders from that time + some old but new sealed emtpy Philips tapes.

I have all, but never used it.  Embarrassed

... maybe in the future.  Wink
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Rafael
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« Reply #13 on: June 01, 2015, 07:35:38 PM »


Yes, more games for the C7420 would be nice, but I wonder how many Videopac collectors own a C7420 and know how to use it?


In fact I never played the games on real C7420. I really don´t know how to load it on real C7420. But I really like to see the scene growing. When I have my Ody corner I intended to make C7420 ready for use.
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TomBeck
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« Reply #14 on: June 01, 2015, 09:16:58 PM »

One reason, that I till now never used the C7420 is, that I have a Jopac connected to my TV. And a Jopac is really not the first choice to connect a C7420.
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