Jump to content

Spirantho

Members
  • Content Count

    1,560
  • Joined

  • Last visited

Community Reputation

2 Neutral

About Spirantho

  • Rank
    Stargunner
  • Birthday 10/20/1976

Contact / Social Media

Profile Information

  • Location
    Aberystwyth, Wales
  • Interests
    Retro gaming!
  1. Much as I dislike replying to my own posts, it might be useful to others. The black screen and constant tone is what happens when nothing is initialised. The usual diagnosis apparently is dead CPU or GROMs (which is really bad news on something as rare as a TI-99/4 as you can't use the /4A GROMs or EPROMs or anything like that). Luckily, I found the schematic here: http://www.99er.net/download2/index.php?act=view&id=61 This showed me that the CPU gets its clock from a clock divider chip, the 74LS362, a.k.a. TIM9904. Looking with an oscilloscope showed nothing on the clock line! Hence nothing was happening at all. This meant almost certainly the TIM9904 or the crystal had gone. So I got both. Yes, you can still get TIM9904s from LittleDiode. Goodness knows how - mine was probably the first they'd ever sold. Both arrived this morning.... tried the TIM9904 - no good. Tried the new crystal (48MHz, incidentally)... and it fired up! One TI-99/4 all running nicely again!
  2. Hi everyone, I finally got around to setting up my TI-99/4 today to get started on Mystery Fun House (Scott Adams adventure). Unfortunately, the TI had other ideas. I was greeted with a blank screen and a constant buzz from the sound chip (which is good - it's alive). From what I can see, this is a common problem.... which instantly makes me suspect the 4116 ICs as they die so easily. However, I've repaired TI-99/4As before which had dodgy 4116s, and the symptom was different. Assuming there isn't a 4116 grounding its output and thereby the data line it's on, what's most likely to be at fault? I'm thinking VDP, GROM or ScratchRAM, as obviously the machine isn't able to start up enough to initialise the sound chip. I'm really hoping that it's not the VDP, but if it is... can I use a TMS9918A in place of the TMS9918? Are the two identical on the outside and just different on the inside? Or do I need a TMS9918 (where on earth am I going to find one of them....?) If it's the GROM, can I 'borrow' it from a TI-99/4a - or maybe an EPROM? Ditto the scratchpad RAM... that'll be the same as a TI-99/4a.... probably. Anyone able to give a hint as to where to start? Oh - one last bit of info - when I have a cartridge plugged in (Tunnels of Doom, of course), it 50% of the time creates a video signal (still black screen but the TV syncs to an NTSC display). Usually there's no video at all which is what you expect when the VDP isn't initialised. I *hope* this means it's failing to start up enough to start the VDP, and that the (very scarce) VDP is ok. Thanks for any help anyone can give!
  3. Hi everybody, (Posted in Atari 2600 forum as this is my focus! Feel free to move it if an admin likes) I've not been very active here in the last few years as I've been doing crazy real life stuff like setting up a business making Android apps (mostly games). I'm thinking of what to do for my next project right now! Just thinking out loud now: just now a thought struck me - would it be useful to people to write an app to keep track of your Atari collection? I'm thinking basically a specialised database, perhaps linking to photos taken by the phone of your precious carts/boxes so when you're going thrifting you'd know exactly what you have? Just an idea germinating in my mind at the moment, but am I allowed to ask: would any of you have interest in such an app? I'd probably sell it at a dollar or two (probably with a free, more limited) version. With Albert's permission I could even link to the AtariAge website, maybe AtariMania too with RomHunter's permission - so in trawling eBay or thrift stores or car boot sales, you could do a quick check on any weird games there are you don't recognise, or see if the one in the store is better than your copy. If enough people would be interested, I may well write this. Heck, if enough people like it, maybe Albert could even brand it an "AtariAge" app for Android. What do people think?
  4. Personally I use Cart Commander (http://www.arcaderestoration.com/) - it's not been updated in ages but does the job just fine for me!
  5. No apology needed on the English! These were all definitely black label Pengos? That's pretty unusual! My Pengo has its instructions - in French! They must have been scattered around Europe but there's still very few of them around.
  6. Hi, I've been repairing an old Teleng Television Computer System - which is essentially the British version of the Interton, and rather similar to the Emerson Arcadia I believe. Anyhoo, it's very nearly working now, but the one problem I'm not sure how to get rid of - the picture is unstable. That is, the vertical hold goes kablooie when certain colours are prevalent on the screen. I've twiddled the knob next to the video generation chip (a PE1X, it seems) and can get it stable for some colours, but never all colours. The top of the display shows the lines at an angle, so instead of: |-----| it's more like /-----/ if you see what I mean. After the first 8 or so lines, they're vertical as they should be. As the VSync is held in roughly this area, I'm thinking the two problems could be related. Does anyone have any idea what to try? I've tried replacing all the caps except two - one of which is miles from the PE1X, the other is the main PSU smoothing cap (the large one). I've reflowed most of the solder joints. I've removed the audio from the signal. I'm currently using a 2N3904 on the video modulator input to grab the composite video, but the same happens with RF. Picture quality is mostly good. Certain colours also send the HSync crazy so the numbers of the score become unreadable. What could cause this? Should I try replacing the colour crystal? It's a 8.86MHz crystal. Any help much appreciated! I can get a photo online if it helps.
  7. Thing is, the PAL database is an open one. There's nothing to stop people changing at reviewing it. Just because I don't have the time any more (nor the money! ) shouldn't stop anyone else. As much as anything else, though, I think it got to the point where pretty much everything got added! Obviously there's still gaps, it's nothing like as complete as Atarimania, but pretty much all the carts people come across are on there, I think. Incidentally, Obelix was actually a pack-in game with the Vader in France, at least for a little while.
  8. Maybe 500 then, I can't believe they'd do a run as small as 150. Then again, you never know. I don't think they did a proper run. Otherwise why would the first 100ish units have a different ROM revision? The first run must have been a prototype or sample run, not a production run. I'd guess they did one more run with V1.02, and then canned the project. That's entirely conjecture though.
  9. As soon as you send me £1000. Not really wanting to sell it because it adds to my Aquarius collection so well. Kind of fits next to the MIB 4-colour plotter quite nicely, I feel. In what way is Martin's QD drive not working? Maybe I can help to get it working... he does know that you need a S2 Aquarius to run it, doesn't he? And he's changed the drive belt? @Tempest: I'd say a lot less than 1,000 were made. Given most of them seem to have V1.01 of the ROM, and at most 106 V1.01 ones were made, I'd say probably 150 were made. Put it this way, it wouldn't look out of place in your (rather awesome) prototype collection!
  10. Yeah, I don't think there are very many of them about these days, probably countable on one hand. My particular one is serial number 15, but I know of a later one with a newer ROM (1.02) which is serial #107. I think it's probably for the best that the Speccy won that fight though.
  11. Hi everybody, Just wanted to let people know that I've put up a video: - I figured these old disk drives won't last forever so it's a good idea to archive them as much as possible now. Any comments gratefully received- hope people find it interesting. Incidentally, if the multi-cart gets the QD ROM on it (and I think it should ) then it's probably actually the ROM from this very machine!
  12. You might want to ask YOK-dfa if he is able to check his Mouse Trap. He believe he has/had what he believe to be a PAL one....
  13. I figured as much. But if it had been PAL the colour palette would have been completely wrong on my Quadrun (which is NTSC only) video I'm about to have a hack at my H6er now, I'll let anyone know if I find out anything...
  14. Who said my machine was PAL? It's an NTSC H6 just like his.....
  15. I've tried all sorts of things. Even changing all the chips. I think I may have changed the regulator too but I'm not sure. You can actually see the effect if you watch my Quadrun video, incidentally (the one on YouTube), I did that on the H6er. From memory I tried changing all the ICs I could, as like you I suspected the TIA at first, and it still happened, so it must be something else, and capacitors are the usual suspects.... Edit: The video is at and the colour shift happens at 5:43.
×
×
  • Create New...