Skip to main content

ZX81 P and O filetype added to TZXDuino with a slight speed update.

ZX81 P and O filetypes have been added to TZXDuino. There is also a minor speed update that shaves a few seconds off previous load times.



We were hoping to have an update to CASDuino with working Dragon CAS files but unfortunately whilst we can get Chucky Egg to work we still can't get others to work. We are still working on it though.

Comments

  1. Hope to try this next weekend on my ZX81 (and Spectrum 48k). I modded v1.3 to work on my Arduino Mega with LCD Keypad shield - need to add the amplifier but for now it works with a headphone;)

    ReplyDelete
    Replies
    1. Nice. Do you have any photographs? It's always good to see other peoples versions.

      Delete
  2. I made a short video of the Ardiuno with shield working:
    https://www.youtube.com/watch?v=jTDi8nEtnpo
    When I manage to test it with my spectrum I'll take more pics!

    ReplyDelete
    Replies
    1. That looks great.
      The amp will be needed I suspect but I do know that many have tested theirs with the ZX81 and have had good results.

      Delete
    2. Sure I have a few audio Amp ICs lying around (TL081 LM741 etc) - I will add one with adjustable gain (I have a small pcb somewhere which I used as headphone preamp) - will post my results.

      Delete
    3. Excellent. Can't wait to see your results.

      Delete
    4. Hi Duncan, I managed to load all the games I threw at it successfully without an additional amplifier. I just added a 2.2uF decoupling cap - here's my 48K loading a couple of games (with composite output mod):
      https://www.youtube.com/watch?v=saPOPK4qcYc
      https://www.youtube.com/watch?v=HtWqcZ2V188

      Delete
    5. How did you connect the cap? That could be an interesting way to make things easier for people. I have to try that myself.

      Delete
  3. The 2.2uF cap is connected in series with the digital output of the Arduino - positive on the Arduino pin which drives the output. I chose a rather small cap as the audio frequency of the output is in the 1-2 KHz range and this will definitely assure the signal. The Arduino Mega (as the Mini and Nano) outputs a 5V max "square" wave which is somewhat integrated by the cap smoothing it off slightly - this is a very high peak to peak amplitude, more than double than a headphone one (2.2V peak to peak on 600 Ohms around 1 milliWatt). The input of the Spectrum is in any case decoupled by a much smaller ceramic 100nF cap in series with a 10K resistor to ALU pin 28 so even connecting it directly should supposedly work though I have not tried it. One important aspect could be line noise or ground loops: if you power the arduino with USB and you don't have a good ground you could be introducing noise. I suggest using a battery powered Arduino (I use any LiPo 2 or 3S I have around) to avoid any ground loop related issues if you are in doubt, at least initially anyhow.

    ReplyDelete
  4. Interesting. Definitely going to have to give that a try to see if it will work on my Speccies and MSX.

    ReplyDelete

Post a Comment

Popular posts from this blog

TZXDuino Firmware 1.16, 1.17, and an updated TZXDuino Instruction Manual

  TZXDuino 1.16 In TZXDuino 1.15.3 I added a bug that lowered the volume of some Spectrum TZX files and all ZX80/81 TZX, O, and P files so they didn't work for many people. I fixed this for 1.16. You can download TZXDuino 1.16 from here.   TZXDuino 1.17 The MAXDuino team added ORIC TAP playback functionality to their firmware which I have adapted to TZXDuino. I don't have an Oric Atmos to test it on so I have been recording the playback and loading on Oricutron and everything I have tried has worked. Obviously things may be different on a real machine. Team MAXDuino have also added a speed up function for Oric TAP files which I will add to TZXDuino 1.18 but so far I have been unable to get it to work correctly. You can download TZXDuino 1.17 from here.   And finally there is the updated instruction manual which now tells you how to access Turbo mode for the Electron, ZX80, and ZX81. It also says for Oric but that has not been implemented yet. You can download the pdf of v...

Arduitape on the ZX Spectrum

How to use the Arduitape with the ZX Spectrum. Sorry I've been a little quiet recently but I've managed to get my grubby little mitts on a ZX Spectrum + 48k and have been testing it with the Arduitape. Unlike the MSX and other 8-bits the only limitations on frequency of the .WAV files is no higher than 22050 Hz due to the limitations of the software used. I was expecting to have all the difficulties of the MSX but I've tested lots of files at different frequencies and they all work fine. I've been using TZX2WAV to do the conversions. Open a command window. Type  tzx2wav -f [desired frequency] [filename].tzx [filename].wav   and that's it. I have been trying to experiment with a programme called OTLA which can output various formats of Spectrum, ZX81, Amstrad, and MSX files that playback at a higher rate and essentially turn a 5 minute loading game in to a 30 second loading game however it outputs at either 44100Hz or 48000Hz which is too high for the Ardui...

New CAS/TZXDuino firmware

New firmware . TZXDuino 1.15.3 Adapted the MAXDuino ID19 code and TurboMode for ZX80/81. To access Turbo Mode for ZX80/81 and Electron please switch Turbo Mode On in the menu Also added UEF Chunk 117 which allows for differing baudrates in BBC UEFs. Added a Spectrum Font for OLED 1306 users converted by Brendan Alford. Option added to userconfig.h Added File scrolling by holding up or down buttons. By Brendan Alford. Download from here. CASDuino 1.24 Added a Spectrum Font for OLED 1306 users converted by Brendan Alford. Option added to userconfig.h Added File scrolling by holding up or down buttons. By Brendan Alford. Download from here.