1k Fight against cancer : the demogames

[dr beep]

Today I tired to load some of your demo games but there seem to be not ordinary. There is missing one character at the end (display file), the ZX81 tapeinterface said there has to be the character 80h. All files with 80h last character could be loaded with no problem. EightyOne can load them with missing this character but I don't know how about Original ZX81. ZX81 tapeloader cancelled operation due to missing 80h character.

Anyway I tried to load in EightyOne Emulator and save new with SAVE command. Files seemed to be loaded and started but could not stopped via break. Even it was not possible to play or use, just showed a screenshot. I expected a little bit more from the demo version, I don't know if it was planned this way.

The missing 80h character is indeed set elsewhere when possible to win a space (it is set on a unused sysvar).
When really needed I must set this back. All demo games should give a playable game (although all with restrictions like no score or just 1 level etc...). Can you tell me which games give the problems? It MUST load otherwise the game has no use!

[PokeMon]

I am using ZX81 tapeconverter to transport .p files to real ZX81 via sound card output. This works perfect but claims the missing 80h in your files. The EightyOne accepts even with missing this byte but maybe can get problems when loading to a real ZX81 in practice.
See here http://www.zx81stuff.org.uk/zx81/tapeut ... rview.html

I wrote some more details about this tape loader in section software here yesterday. Java archive, really easy to use. Maybe good to give as info to your games.

This documentation about the ZX81 data structures give some details about tape loader files.

.81 and .80 Files
These are 1:1 copies of the content of real ZX81 and ZX80 cassette files.
ZX81 files are copies of the memory area 4009h up to E_LINE-1, the filename
(which is usually part of ZX81 files) is not included in the file.

As chapter 27 organization of memory in Sinclair manual, E_LINE marks "line beeing typed and workspace". So E_LINE-1 points to the marker 80h which marks end of variables. As I prooved many other files on my disk with ZX81 programs, all have this byte 80h. And all could be transferred to my real ZX81.
So since this is only one byte, I would add it for compatibility. Also ZX81 does this when saving contents with SAVE "..." - even EightyOne emulator.

The games - I have tested three. I will check up again and give you more information. By the way - there is no manual for the games - so I don't know what keys to use.

[PokeMon]

memdemo is working now - tried to press keys Q,A,Z and somethings happen. But I don't know what and how to play.
blocdemo is doing all itself, regardless which key I press - counting down to 0 and then stop, a thick line is moving on the screen
othedemo is starting with a nice screen but not reacts on any keypress - dont know how to play

Anyway - I am not an experienced gamer.

[dr beep]

I am using ZX81 tapeconverter to transport .p files to real ZX81 via sound card output. This works perfect but claims the missing 80h in your files. The EightyOne accepts even with missing this byte but maybe can get problems when loading to a real ZX81 in practice.
See here http://www.zx81stuff.org.uk/zx81/tapeut ... rview.html

I wrote some more details about this tape loader in section software here yesterday. Java archive, really easy to use. Maybe good to give as info to your games.

This documentation about the ZX81 data structures give some details about tape loader files.

.81 and .80 Files
These are 1:1 copies of the content of real ZX81 and ZX80 cassette files.
ZX81 files are copies of the memory area 4009h up to E_LINE-1, the filename
(which is usually part of ZX81 files) is not included in the file.

As chapter 27 organization of memory in Sinclair manual, E_LINE marks "line beeing typed and workspace". So E_LINE-1 points to the marker 80h which marks end of variables. As I prooved many other files on my disk with ZX81 programs, all have this byte 80h. And all could be transferred to my real ZX81.
So since this is only one byte, I would add it for compatibility. Also ZX81 does this when saving contents with SAVE "..." - even EightyOne emulator.

The games - I have tested three. I will check up again and give you more information. By the way - there is no manual for the games - so I don't know what keys to use.

Most games use QAOPZ or cursor

[dr beep]

Here are the new demo versions in 1 ZIP-file.
All files now have 128 as last byte.

Are these now OK?

[sirmorris]

I'll check these out tomorrow.
c

[dr beep]

Hello guys, I do need the input or I can't bring this to market.

Thanks!

[sirmorris]

Sorry - I don't have a good memory :¬.

[dr beep]

Sorry - I don't have a good memory :¬.

Do you need new chips or just a refresh with the R-register?

[angus]

I should have a ZXpand very soon....then I shall try them