Search found 158 matches

by kmurta
Thu Apr 02, 2020 6:30 pm
Forum: Hardware
Topic: Clock doublers
Replies: 1
Views: 303

Re: Clock doublers

Has anyone built or used one of the ZX81 clock doublers ? If so where there any gotyas or was it difficult to get working ? I use it through the ZXULA-2, an ULA replacement made by Andy Rea some time ago: ZXULA2.jpg Here it running the CLCKFREQ test, with ZXpand patched with ZX81X2 ROM: https://you...
by kmurta
Sun Mar 08, 2020 4:48 pm
Forum: Development
Topic: JOY81 - Programmable Joystick Interface for ZX81
Replies: 93
Views: 28256

Re: JOY81 - Programmable Joystick Interface for ZX81

This is one more example, where multiple keys may be pressed at the same time: while holding the fire button down (e. g. SPACE key), it is possible to move the craft up(A)/down(Q)/right/left: http://www.zx81stuff.org.uk/zx81/tape/3DDefender But Siggi, the interface works like this, I don't understa...
by kmurta
Sat Mar 07, 2020 5:23 pm
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

The purpose of these small samples of modifications is not to denounce problems in this game, but to show that the basic standard can very well be adapted on the Zx81, but with small tricks specific to the machine. Don't worry about it, I appreciate your suggestions, they are welcome ;) My intentio...
by kmurta
Sat Mar 07, 2020 5:05 pm
Forum: Development
Topic: JOY81 - Programmable Joystick Interface for ZX81
Replies: 93
Views: 28256

Re: JOY81 - Programmable Joystick Interface for ZX81

Hi Kelly is it possible to configure also keypresses, which are recognized as valid (when a game in M/C scans the keyboard directly), but which do not lead to a valid ZX81 key? Currently the interface can generate a single key, valid for BASIC. I am thinking of that situation: a m/c game scans the ...
by kmurta
Thu Mar 05, 2020 3:36 am
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

Well remembered, BASIC Sinclair already initializes arrays with a value of 0, unlike other BASICs. In this sense, we can also discard the following lines of code: 530 FOR I=1 TO 9 532 LET C(I,1)=0 535 LET C(I,2)=0 538 NEXT I and 670 FOR I=1 TO 8 680 LET D(I)=0 690 NEXT I However the impact on game s...
by kmurta
Sun Mar 01, 2020 1:30 am
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

I uploaded a new version (see in the first post), in the first one I used the PAUSE statement and this was causing conflict with the RAND statement to generate the RND seed. Some game configurations were repeating themselves very often, they weren't exactly random. With the changes this has been fix...
by kmurta
Sun Mar 01, 2020 1:18 am
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

A couple of those screens remind me of the German Star Trek theme game 'Enterprise' which was published by ISS (the exclusive German Sinclair Importer) and was by Kilian Schlaich. I am actually in contact with him from time to time. I have permission to share it, so here it is as a .p file (for the...
by kmurta
Sun Mar 01, 2020 1:16 am
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

dr beep wrote:
Thu Feb 27, 2020 7:05 pm
I think this should fit 16K machinecode.
It's possible, but would it be worth the effort?

There are already several versions in BASIC that fit in 16Kb, of course many simplifications have been made to achieve this.
by kmurta
Sun Feb 16, 2020 8:21 pm
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

A point to note for ZXpand users. Don't rely on the program setting RAM-TOP to 49152! Before loading you must use the CONFIG"R=49152" command before loading otherwise a nasty little whiteout happens. I tried this on four different spands ( issue 1,3 and 5 and the xpand+ ) and they all crashed unles...
by kmurta
Sun Feb 16, 2020 4:46 pm
Forum: GAMES
Topic: Super Star Trek
Replies: 23
Views: 7906

Re: Super Star Trek

I have always had a liking for this game so many thanks for this kelly. :D You're welcome! You may or not know that a double speed BASIC ROM is available now for the 81 and I will try this with that ROM to see if it speeds things up. Yes, I know it and I even tested the game with this improved ROM ...