Search found 57 matches

by kpalser
Tue Dec 06, 2016 11:07 pm
Forum: Emulators
Topic: ZX81 emulator for iOS
Replies: 81
Views: 16392

Re: ZX81 emulator for iOS

Actually how about the ability to save programs you type in? I'll give it some thought. There's certainly nothing in the Apple developer guide prohibiting saving your own programs. Probably more along the lines of a complete memory capture of the 16k of address space plus the registers rather than ...
by kpalser
Tue Dec 06, 2016 9:57 pm
Forum: Emulators
Topic: ZX81 emulator for iOS
Replies: 81
Views: 16392

ZX81 emulator for iOS

Hi all, Apple approved my ZX81 emulator for iOS today: http://zx81-ios.weebly.com Consider it just the first step of an app that I hope to extend with more functionality, software titles and eventually an interview section. Currently I'm working on a more game friendly version of the virtual keyboar...
by kpalser
Sat Dec 21, 2013 8:31 pm
Forum: Hardware
Topic: Very low signal on MIC port
Replies: 30
Views: 4960

Re: Very low signal on MIC port

Thanks for the information and suggestions. A little bit of background - I’m just trying to get wave characteristics that accurately represents the original device, flaws and all, for an emulator project. For the moment I’m holding off making any mods to the device. I did follow Mark's suggestion of...
by kpalser
Mon Dec 16, 2013 11:12 pm
Forum: Hardware
Topic: Very low signal on MIC port
Replies: 30
Views: 4960

Re: Very low signal on MIC port

In the event that my evening of experimenting might be useful to others googling this and subsequent similar threads ... My three ZX81 (like everyone else’s unmoded units) are producing a weak signal from the MIC port. Since I wanted to double check the documented: Each pulse is split into a 150us H...
by kpalser
Sun Dec 08, 2013 12:03 am
Forum: Emulators
Topic: Side margin with Z-Xtricator
Replies: 8
Views: 2366

Re: Side margin with Z-Xtricator

So after a week of evenings reviewing all timing and cycle calculations to try and account for my emulator having the equivalent of two character spaces in the left hand side (LHS) margin and six in the right (RHS), I decided to load Z-Xtricator up on a real ZX81… So obviously in the photos below I’...
by kpalser
Tue Nov 26, 2013 11:17 pm
Forum: Emulators
Topic: Side margin with Z-Xtricator
Replies: 8
Views: 2366

Re: Side margin with Z-Xtricator

Checked out Spud81 and it is the best screen centred emulator for Z-Xtricator. If you see the attached screenshot on another Software Farm hires game, in these cases Spud81 demonstrates a larger left margin and so with Z-Xtricator it looks squarely centred. (Not criticisng Spud81 - I think it is a s...
by kpalser
Mon Nov 25, 2013 9:44 pm
Forum: Emulators
Topic: Side margin with Z-Xtricator
Replies: 8
Views: 2366

Side margin with Z-Xtricator

Folks, To further my challenge of perfecting my zx81 emulator I shifted testing to focus on Z-Xtricator and its pseudo hires INT mode 2 routine. It has been an excellent exercise for identifying and correcting some flaws. Some questions: 1) Have any of you fired up Z-Xtricator on a real ZX81 recentl...
by kpalser
Sun Aug 04, 2013 8:26 pm
Forum: Emulators
Topic: Help with ZX81 loading screen for new emulator
Replies: 18
Views: 4457

Re: Help with ZX81 loading screen for new emulator

This response is mainly for Rink but the points at the end might be of general interest. To be be fair the the changes in the iOS app store are no longer recent. For a while now Apple have allowed interpreted code to run on their iOS devices. There were restrictions on the languages that could be us...
by kpalser
Sat Aug 03, 2013 7:13 pm
Forum: Emulators
Topic: Help with ZX81 loading screen for new emulator
Replies: 18
Views: 4457

Re: Help with ZX81 loading screen for new emulator

PokeMon, Thanks for the extra info and link! Sirmoris, Love to expand the emulation to include zexpand in the future, thanks for the interest. I will find the time... The emulator is quite a long term project. Since I coincidently moved to Dundee three years ago, I have interviewed workers and shop ...
by kpalser
Sat Aug 03, 2013 1:05 am
Forum: Emulators
Topic: Help with ZX81 loading screen for new emulator
Replies: 18
Views: 4457

Re: Help with ZX81 loading screen for new emulator

In my quest for improving the accuracy of the video emulation, I made an observation and hit a point that is still bugging me. Firstly, I noticed for the sudo hires Forty Niner game that the internal vertical window has to be up to around 21.3ms. If not, the program controlled vertical sync is not r...