Texas Instruments TI-99/4A video RAM fix

Sdílet
Vložit
  • čas přidán 13. 05. 2024
  • ▶Neol's Retro Lab's initial TI99 video: • TI-99/4A - Powering Up...
    ▶Donations: www.paypal.me/flashjazzcat
    ▶Tip or donate: ko-fi.com/flashjazzcat
    ▶Patreon: / flashjazzcat
    ▶Website: www.atari8.co.uk
    ▶Odysee channel: odysee.com/@flashjazzcat
    ▶Facebook: / atari8
    00:00 Introduction
    01:44 Reproducing the fault
    04:02 Inventory of peripherals
    05:45 A look at the motherboard
    10:37 Diagnosis and repair
    14:49 Power-on test
    16:00 Fully reassembled
    17:44 A proper test
    18:07 Attempting to program in TI BASIC
    20:22 Munchman and another strange quirk
    24:39 Summary and conclusion
    Soldering and test equipment:
    ● Hakko FX-951 T12 soldering station: uk.farnell.com/hakko/fx951-64...
    ● Best BST-863 hot air rework station: www.banggood.com/BEST-BST-863...
    ● Anesty (Duratool) ZD-915 thru-hole desoldering station: cpc.farnell.com/duratool/d006...
    ● Hanmatek DOS1102 dual-channel oscilloscope: www.amazon.co.uk/DOS1102-osci...
    ● Amtech NC-559 Tacky Flux: store.rossmanngroup.com/index...
    ● Goot Wick Desoldering Braid: store.rossmanngroup.com/index...
    ● Cynel Sn60Pb38Cu2 Tin/Lead Solder Wire: www.tme.eu/gb/details/lc60m2-...
    ● SysCheck v.2.2 by tf_hh: www.abbuc.de/component/jshoppi...
    Equipment and software used for video production:
    ● Open Broadcaster Studio: obsproject.com/
    ● 2x Logitech Brio webcams: www.amazon.co.uk/Logitech-Gam...
    ● USB AV/s-video capture dongle: www.amazon.co.uk/Ex-Pro-Grabb...
    ● 135W Photography Studio Softbox Light: www.ebay.co.uk/itm/135W-Photo...
    ● Final Cut Pro
    ● Apple Motion
    ● 15" mid-2015 Apple Retina MacBook Pro
    #atari
    #retrocomputing
  • Věda a technologie

Komentáře • 29

  • @cbmeeks
    @cbmeeks Před 13 dny

    The TI-99/4a was my first computer. I have many of them now and still use them. It really is a strange computer that you either love like me, or hate. lol

  • @adamv242
    @adamv242 Před 17 dny +1

    A lifelong Atari fan, I always had a fondness for the TI as well. Great keyboard, a very nice built-in BASIC.

    • @flashjazzcat
      @flashjazzcat  Před 17 dny

      I really liked this machine too, which is why the various puzzling design decisions regarding the keyboard editor, etc, are so frustrating.

  • @tenminutetokyo2643
    @tenminutetokyo2643 Před 15 dny

    Nice lighting!

  • @mikegage3326
    @mikegage3326 Před 15 dny

    Nice work.

  • @jonathanwhiteside6092
    @jonathanwhiteside6092 Před 15 dny +2

    Of all the computers I own, I have to say that the TI 99/4a has the best video signal of them all in unmodified form. I use a CoolNovelties component cable via an OSSC to HDMI and the image quality is unmatched other than by machines like my 65XE and 800XL that have VBXE's fitted. Weird machine though.

    • @cathrynm
      @cathrynm Před 15 dny +2

      Suspect TI had decent analog engineers around at the time they designed this machine.

    • @flashjazzcat
      @flashjazzcat  Před 15 dny +2

      Seems so, yes. I've been reminded of the RGB mod for this machine, which is apparently sublime, but not having even seen component first hand, I'm sure it's excellent given the quality of RF out of the box.

  • @JoseArzacSolis
    @JoseArzacSolis Před 15 dny

    My first computer was a TI-99/4A. I loved it. The packaging, manuals and documentation were excellent. And I did use a tape recorder to store programs, but I never got a voice synth.

    • @flashjazzcat
      @flashjazzcat  Před 15 dny

      Yes: presentation was generally excellent. Just such a quirky machine with the benefit of hindsight.

  • @NotMarkKnopfler
    @NotMarkKnopfler Před 15 dny +1

    To delete a character, move the cursor back (fctn key and S key) on top of the character, then press fctn 1 (DEL). Easy when you know how 😅 still not as complex as the spectrum keyboard 😊

    • @flashjazzcat
      @flashjazzcat  Před 15 dny

      LOL - thanks for that. Easy when you know how, as you say. :D

  • @PG-gs5vb
    @PG-gs5vb Před 15 dny +1

    You have to put a chatty dwarf inside the speech synth box to make it work.

  • @ukcroupier
    @ukcroupier Před 15 dny

    The RF signal on mine is superb too, actually better than the component using coolnovelties cable (not a dig at coolnovelties, i think the machine is just built that way)

  • @cbmeeks
    @cbmeeks Před 13 dny

    On the speech synthesizer, the door does nothing. It was meant to accept new speech ROMS but that never happened. And as for the joysticks...they are quite awful as you will soon discover. LOL

  • @MoparStephen
    @MoparStephen Před 16 dny +1

    I wonder if rufies can erase the TI's 16k of memory? Bill would know!

    • @flashjazzcat
      @flashjazzcat  Před 15 dny

      Not according to the Pennsylvania Supreme Court, LOL

  • @NotMarkKnopfler
    @NotMarkKnopfler Před 15 dny

    The PAL TI-99/4A outputs YUV from its video connector. Maybe that's why the cable doesn't work?

    • @flashjazzcat
      @flashjazzcat  Před 15 dny

      You mean that the component inputs on the TV might be particular about it being YPbPr instead?

  • @joopidema
    @joopidema Před 14 dny

    There is a fix for that Alpha Lock problem using a diode.

    • @flashjazzcat
      @flashjazzcat  Před 14 dny

      Really? I assumed this was by design owing to signal contention with the joystick or something. Nice.

  • @jasejj
    @jasejj Před 15 dny

    This was a capable and interesting machine, but unfortunately it was never going to work in the UK. We used tape for games in the early days, and typically never bothered to expand our machines. Out of the box, the TI was completely unsuited to games thanks to the machine's inability to run machine code from BASIC, which immediately prevented good quality cassette based games from being available.
    I thought at first that this might have been my friend's machine from back in the day - as there can't have been many of these in the North East (friend lived, still does, in Sunderland). His dad was a massive Sanyo fan so it surprised me even at the time that he ended up with one of these rather than an MSX!

    • @flashjazzcat
      @flashjazzcat  Před 15 dny

      Stuff comes in from all over the country (and world, in fact), although I do get the odd local client coming down to the house in a car. This one was posted in last year from somewhere in the UK, but I suppose you never know where this machine's been during its long history.

  • @NotMarkKnopfler
    @NotMarkKnopfler Před 15 dny

    The door on the speech synth doesn't serve any function. The original intention was to produce different voice ROMs with male/female voices and different vocabularies etc. but it never came to fruition.

    • @flashjazzcat
      @flashjazzcat  Před 15 dny

      Ah - thanks. So it's bascially just a handy storage compartment. :)

  • @alexcochrane1966
    @alexcochrane1966 Před 15 dny

    Good computer, terrible joysticks. The speech synthesizer needs speech enabled carts or extended basic.