Search found 54 matches

by zx81user
Fri Apr 26, 2013 4:28 am
Forum: Hardware
Topic: Simple Video Mod for 210ULA
Replies: 19
Views: 10812

Simple Video Mod for 210ULA

I received another TS1000 but I couldn't get my TV card to tune in to the modulator RF channel. So I thought I would take the board out of the modulator and feed the video signal directly into the TV. Although this worked, the video was very dark and I had to increase the brightness and contrast to ...
by zx81user
Tue Apr 23, 2013 11:58 pm
Forum: Development
Topic: Read keyboard from assembly
Replies: 16
Views: 5002

Re: Read keyboard from assembly

[quote="dr beep"This will give the value of the key 1-40 for shift to space in A-reg. Also alternating HL and BC (as you can see)[/quote] waitkey LD HL,lastk LD A,255 LD (HL),A wkey CP (HL) JR Z,wkey ; 255 means no key pressed LD BC,(lastk) ; read IN port and value CALL #7BD ; translate IN port and ...
by zx81user
Tue Apr 23, 2013 11:14 pm
Forum: Development
Topic: Read keyboard from assembly
Replies: 16
Views: 5002

Re: Read keyboard from assembly

If you need to read more than one key at once (for diagonal movement, or running+jumping, for example) then you'll need to scan the input port ($FE) directly. I'll post up full information about that if it's required (don't have it to hand at the moment) Scanning the port would give me the same res...
by zx81user
Tue Apr 23, 2013 11:11 pm
Forum: Development
Topic: ZX81 Nixie Clock
Replies: 10
Views: 2614

Re: ZX81 Nixie Clock

you can put one there of course but you wouldn't be able to use the clock and run another program at the same time. You could use the tubes to display a game score or something like that :idea: The software runs based on interrupt events, so in theory it is possible to run the clock and another pro...
by zx81user
Mon Apr 22, 2013 11:40 pm
Forum: Development
Topic: ZX81 Nixie Clock
Replies: 10
Views: 2614

Re: ZX81 Nixie Clock

I posted the clock circuit and high voltage circuit to a dedicated facebook page:
https://www.facebook.com/Zx81NixieClock

Michel
by zx81user
Mon Apr 22, 2013 11:03 pm
Forum: Development
Topic: ZX81 Nixie Clock
Replies: 10
Views: 2614

Re: ZX81 Nixie Clock

Hi Guys, thanks for the replies. I will post the schematic later today, the plain PCB will be $50 without parts or $175 including everything except the Zeddy ;-) I don't think it is a waste to use a Zeddy to drive a nixie clock, the Zeddy's cost next to nothing these days so to put one aside as a ni...
by zx81user
Mon Apr 22, 2013 9:21 am
Forum: Development
Topic: ZX81 Nixie Clock
Replies: 10
Views: 2614

ZX81 Nixie Clock

After cleaning out the garage a few weeks ago and stumbling across my good old ZX81 (well, TS1000 really), I thought it would be quite interesting to turn it into a Nixie Clock! Here's the result: DSC_0063 (640x384).jpg I designed it with TTL logic, no SMD components here. It is direct drive using 4...
by zx81user
Mon Apr 22, 2013 2:55 am
Forum: Development
Topic: Read keyboard from assembly
Replies: 16
Views: 5002

Read keyboard from assembly

What is the easiest/best way to get keyboard input in an assembly program? Is there a OS call that returns for example the key code if a key is pressed or say $ff if no key is pressed?

I need to read many keys, 0-9 and A-Z so to speak.

Michel
by zx81user
Sun Apr 21, 2013 11:29 pm
Forum: GAMES
Topic: What to write next...?
Replies: 27
Views: 5799

Re: What to write next...?

+1

This was the Nr1 game for me to play on the Vectrex! http://www.youtube.com/watch?v=3EdRmZ6n7wI I don't know if it is very different from the Arcade game though.

Michel
by zx81user
Sun Apr 21, 2013 1:05 pm
Forum: Hardware
Topic: Ceramic Resonators (zx81)
Replies: 16
Views: 4716

Re: Ceramic Resonators (zx81)

ksng36 wrote:I tried this today on two different Issue 3 boards and they both worked fine. I found some 6.5Mhz crystals on Ebay.
Was that a drop-in replacement or did you need to change/add capacitors?

Michel