Search found 340 matches

by RMartins
Fri Jun 21, 2019 7:22 pm
Forum: Programming
Topic: The perfect fall/jump
Replies: 24
Views: 739

Re: The perfect fall/jump

The main reason it doesn't look right, is that the ball suddenly stopped moving forward while falling. My picture is misleading—it allows horizontal movement during fall and I just stopped pressing the key. To feel smooth, user input needs to control acceleration, not velocity or position (X in thi...
by RMartins
Fri Jun 21, 2019 6:18 pm
Forum: Programming
Topic: Zeus assembler - code generation?
Replies: 16
Views: 780

Re: Zeus assembler - code generation?

The instructions are realistic in the sense that they’re implemented as fast as is possible with a 28MHz master clock and an extra 4Ts for the prefix fetch. Things can happen on every rising and falling edge of that clock, which the Z80 designers did not have access to in their design. They had fou...
by RMartins
Mon Jun 17, 2019 8:41 am
Forum: Showcase your work!
Topic: I made a new App for the Multiface 3
Replies: 26
Views: 1377

Re: I made a new App for the Multiface 3

Just a suggestion.
You could remove the false positives, by checking if the contents have all bits set, or all bits reset.
If every bit is 1, or every bit is 0, in a specific char, there is no hidden content, it's just a color.
by RMartins
Wed Mar 06, 2019 8:12 pm
Forum: Showcase your work!
Topic: ZAD Adventure System - Progress
Replies: 55
Views: 6099

Re: ZAD Adventure System - Progress

This has gone a long way. from the initial screens. 8-)

Hoping to see this finished in the near future. :geek:
by RMartins
Tue Feb 12, 2019 4:24 pm
Forum: Sales/Commercial
Topic: Wanted: tape deck part for +2
Replies: 5
Views: 562

Re: Wanted: tape deck part for +2

Have you considered 3D printing the part ?

Regardless, a picture of the wanted part, might help your quest
by RMartins
Sun Dec 30, 2018 12:33 am
Forum: Hardware
Topic: Gray color, a second after power up
Replies: 4
Views: 392

Re: Gray color, a second after power up

Thanks So from that source When used with PAL, the colour subcarrier is 4.43361875 MHz ... That's exactly the frequency of the crystal used for generating the PAL output (4.4336MHZ) on the Spectrum. So I'll try to measure if that's what I'm getting, although is not very easy to measure since it's no...
by RMartins
Sat Dec 29, 2018 3:13 am
Forum: Hardware
Topic: Gray color, a second after power up
Replies: 4
Views: 392

Re: Gray color, a second after power up

Obvious first “stupid” question, does your display work okay with other ZX Spectrums of the same type? Yes Which issue board does your colour shy ZX Spectrum have? Issue 3 And I presume you have looked at the video signal with an oscilloscope? Correct. So have you checked the frequency that the col...
by RMartins
Fri Dec 28, 2018 10:15 pm
Forum: Hardware
Topic: Gray color, a second after power up
Replies: 4
Views: 392

Gray color, a second after power up

Hi, guys Long time no see. Life has kept me busy with other stuff. I'm working on reviving another ZX48, which is already working, after a few required fixes (Power transistor, damaged high memory chip, etc ...). But it still has this strange glitch, where it loses color after a second of power on. ...
by RMartins
Fri Aug 10, 2018 7:07 pm
Forum: Hardware
Topic: 128K +2 Works with divmmc but alone not
Replies: 2
Views: 291

Re: 128K +2 Works with divmmc but alone not

DivMMC, the regular one, starts by copying the ROM to internal DivMMC memory. I'm not sure the DivMMC Future does the same, but it probably does since it's a feature of the DivMMC OS. It could in fact be a ROM problem, but due to what I said above, I doubt it. It might be related with memory (RAM), ...