Search found 21 matches
- Thu Mar 04, 2021 6:34 pm
- Forum: Hardware
- Topic: Wait mod + ZXPand+ issues
- Replies: 2
- Views: 1226
Wait mod + ZXPand+ issues
Hello wizards! I tried the "why wait" mod on my issue 3 ts-1000 (using the default 2907 transistor) and it worked perfectly fine for long minutes, a sweet 10% speed boost and stable picture. But when using it with my ZXPand+, I would get progressively more RAM corruption whenever I would shift-reset...
- Sat Jul 04, 2020 2:54 am
- Forum: GAMES
- Topic: Tractor Beam - Galaga style game
- Replies: 10
- Views: 13860
Re: Tractor Beam - Galaga style game
Well done! The best Galaga-style game I've played on the Zeddy. I haven't managed to make it work with my zxpand joystick but I'm still figuring that out so maybe my fault. I don't have UDG or Chroma, just needs a catchy song on the zonx to be as good as can be (unless you make it hi res without ext...
- Mon Jun 01, 2020 1:10 am
- Forum: Hardware
- Topic: Using a microcontroller for clock doubler?
- Replies: 7
- Views: 2470
Re: Using a microcontroller for clock doubler?
I must persist :) I think I have a heat stroke, my brain isn't working very well so I just can't stop thinking about this. :) The zx81 expansion port has basically all the signals a clock doubler needs, /IORQ, /HALT, WR and so on, and of course /CLK. Could a simple expansion be made to hold the logi...
- Sat May 23, 2020 2:33 am
- Forum: Hardware
- Topic: Using a microcontroller for clock doubler?
- Replies: 7
- Views: 2470
Re: Using a microcontroller for clock doubler?
Okay, my idea was to assume that the required clock pulse would follow a predictable pattern, 3.25 Mhz when displaying a char, 6.5 Mhz otherwise, so you could literally write a program with a line for every pixel or scan jump to generate the clock pulse or skip it (for half speed). Run the MC at 6.5...
- Fri May 22, 2020 5:52 pm
- Forum: Hardware
- Topic: Using a microcontroller for clock doubler?
- Replies: 7
- Views: 2470
Re: Using a microcontroller for clock doubler?
"Randy" = Andy Rea, doh, thanks for sorting me out, seems obvious in hindsight. :) As for hardware requirements, as far as I can tell the ZXpand+ can handle 6.5 Mhz so RAM speed shouldn't be a problem? The whole idea of the Baker/Rigter "clock doubler" is to drop down to "SLOW" 3.25 Mhz clock whenev...
- Thu May 21, 2020 6:52 pm
- Forum: Hardware
- Topic: Using a microcontroller for clock doubler?
- Replies: 7
- Views: 2470
Using a microcontroller for clock doubler?
Hi everyone! I'm hardware-innocent and for the two days I've been looking into clock doubler designs that I could build cheaply and easily. Unfortunately even the simplest and latest designs from Wilf date from 2003 and still needs 3 IC and enough ability to be able to build the circuit correctly. T...
- Wed Jan 29, 2020 2:20 pm
- Forum: Welcome Area
- Topic: Bonjour from France
- Replies: 6
- Views: 4468
- Tue Dec 10, 2019 3:17 pm
- Forum: Development
- Topic: New year, new projects?
- Replies: 12
- Views: 9669
Re: New year, new projects?
Another visitor? Stay a while... Staaaay forever!
The digitized death yells on Impossible Mission were so impressive on the C=64 that one day my big sister rushed down the stairs fully expecting her little brother to be crispy & smoking.
Great design on the port even without sound.
The digitized death yells on Impossible Mission were so impressive on the C=64 that one day my big sister rushed down the stairs fully expecting her little brother to be crispy & smoking.
Great design on the port even without sound.
- Tue Sep 03, 2019 12:19 am
- Forum: Hardware
- Topic: A homemade ZX81 keyboard of wood
- Replies: 13
- Views: 5979
Re: A homemade ZX81 keyboard of wood
Because nothing compares to a real Cherry Keyboard with ZX81 professional printed keycaps. :mrgreen: My homemade keyboard has Cherry keys (well... Chinese Cherry, I ripped out the keys from the cheapest keyboard I could find :) ) but I haven't figured out how to "professionally" print the keycaps. ...
- Mon Sep 02, 2019 3:58 pm
- Forum: Hardware
- Topic: A homemade ZX81 keyboard of wood
- Replies: 13
- Views: 5979
Re: A homemade ZX81 keyboard of wood
That looks like the keyboard from a TI 99/4A with extra timer circuitry for repeats & new functions. See TI99 keyboard adaptation for wiring help without the new circuits.
TI99/4A's are more common than Zeddies so why not sacrifice one to do this. O
TI99/4A's are more common than Zeddies so why not sacrifice one to do this. O