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About helocast

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  1. Yes, pin 4 -CRUCLK and pin 6 CRUIN have no motherboard connection to the GROM port/riser. Just happens I've been spending the past month going over trace/component by trace between both models for a project. What I have not been able to detail on the FG99 because I don't have the schematics is the use of Vss, GROM port pins 33 & 35 (the odd little -.72V used to pull the line slightly below system ground). The standard TI-99/4A used a cap, resistor, and diode to provide that, but to "save" cost didn't make the final QI design and they just tied both pins 33/35 to ground. I know in Ralph's own troubleshooting he noted the FG99 is doing what it is supposed to, minus making final menu visible/actionable. These are really the only differences between the GROM ports unless you want to discuss the way pin 1 RESET is realized between the two, but that doesn't apply here. I have to assume TI engineers kept timings identical between revisions, but we know GROMs are very poor drivers because of the single transistor managing both pull up and pull down on its data lines. I throw something together in the FG thread whenever I get this little project of mine finished. Doug
  2. I guess I should've sent this zipped when you bought my FinalGrom99 ... didn't think about it at the time. Consider my PC hard drive like the Wayback Machine when it comes to TI stuff, even though I never use 99.9% of the files I get/find through this forum. I snapshot'd this back on July 12, 2017, at least that's what the file(s) creation date tells me (well prior to the existence of Ralph's current updates folder published 13 months? ago). Maybe it contains the originals required (not responsible if people break things). As to "building" the cpld file, there seems to be instructions at the end of the README.md file but it's all alien👁️‍🗨️ to me. Hopefully it helps someone. Doug finalgrom99-master.zip
  3. helocast


    Ebay funkward-tech https://www.ebay.com/itm/TI-TMS9901NL-TMS9901NL-40-TMS9901-Programmable-System-Interface-DIP-40-x-1pc/151076609192 has always been reputable to me. Only had one order out of probably two dozen where I was physically shorted DRAMs, but they made it up. I've had zero fakes in my dealings, but I'm about due. Doug
  4. Appreciate the offer. PM'd OLD CS1. I'll keep my reply short since I'm in Dev. I really wanted it to work ... if nothing else to have a piece of every tech offered here. I can't keep up, but retired pension/money permitting I try. Doug P.S. Brewing Academy on Ebay still swears up and down this combo "works" and I've sent them a message to alter their listing in that regard. ¯\_(ツ)_/¯
  5. Considering I only run/own V1 QI, I'm still wondering what to do with my FG purchased early in 2018? Can we get credit/trade-in against a future SDD99 sale if that will finally support the QI? Doug
  6. A little slower, 55ns vs 45ns and wider voltage supply range. Other than that it is also in the 44-pin TSOP II package. $6.92 AS6C8008-55ZIN https://www.mouser.com/datasheet/2/12/AS6C8008-1288432.pdf I haven't checked compatibility any closer than that. Doug
  7. It's Quora, which I give about equal footing on the level of Wiki for delivering dependable answers from "experts", but: https://www.quora.com/Some-powersupplies-can-be-switched-between-110V-and-220V-Will-leaving-the-switch-in-the-wrong-position-damage-only-the-powersupply-or-also-anything-connected-to-it#:~:text=If the switch is left,power supply or device results. Doug
  8. 👍Looks like you're progressing ... always good. I just wanted to address terminology in my last "help". Thierry does theory WELL (as do probably most of the seasoned contributors here). I know enough to be dangerous, but I always try to consolidate links, pics, sources since projects and references also seem to be scattered to the four winds over the years. With that said, http://www.harmlesslion.com/text/atx_peb.htm seems to be the project you are following. Might I also suggest Chris (Shift838 here) as a source since I know he did a great write-up on solving all of this AND putting PEB cage in a modern PC case. What I observe: It looks like your PSU has six rails supplying max peak of 750W. If you "math" what each rail could provide max, you get 823.6W, yet you are still limited to any combination of rails not totaling PSU rating of 750W. TI spec'd/budgeted original supply to not more than ~4W on unregulated +8V rail to include a floppy drive, ~3.75W on unregulated +15/16V rail to include a floppy drive, and finally ~4.5W on unregulated -15/16V rail? Divide each of those rails up among 8 PEB slots plus a drive respectively and you can see there wasn't a lot of excess power and why only one drive was officially supported - actually quite puny! I'd suggest keeping your two yellow +12V rails separated, one powering backplane and one powering noisy accessories (fans, drives), common grounds. I don't know what your full complement of cards and accessories for your system are. I'd also suggest using the +5VSB rail (see attached picture as an always-on source for a TIPI if you have one and perhaps a standby panel light. Thinking aloud: I personally can't see how a modern PSU provides enough overhead for the relatively power hungry 7805s or 7812s of the day. +8V was chosen to provide 2.5-3V overhead just as the +16V was chosen to provide 3.5-4V overhead to respective regulators. Also of course over time, some users/techs may have bypassed regulators on individual cards to control heat and chose to supply regulated +5/+12/-12V. If they did that they should have annotated on the card/shell that was done to prevent plugging in a modified card into an unmodified PEB. I guess it has been successfully done, so I'm not trying to impune anybody's successes previously. As I said, I just try to consolidate and combine info into a one-stop reference ... and those aren't all that pretty (tough conveying all the information and I suck at that). My 2 cents. Interested to see how this turns out and as always, good luck and low magic smoke release! Doug
  9. You'll have to fool your ATX supply on the power good signal. Here's the project for that https://www.overclockersclub.com/guides/atx_psu_startup/ with a couple variations. Also, once you disassemble your PEB, you should have your power/ground planes already marked and color coded for you: Doug
  10. I very much appreciate your support. I popped in to say that you can cross me off your list of having install problems for now and saw this post, so I'm replying here. What fixed it? I don't know. I DID go back and reflow all the pins on the tall extension header between the PI Zero W and the TIPI speech board. As was mentioned here in another reply, I don't do sloppy soldering despite old eyes ... so yes I also visually went back over the dual supplied headers I had soldered along the right side of the PI - no bridges there. This is new and exciting tech and application in the TI world (even though I'm a late adopter), so even though this isn't your product you are to be commended it works in sidecar, PEB-, and speech-synth formats. Doug P.S. V2.4 is stable! 😁
  11. This 2015 thread https://atariage.com/forums/topic/241337-ti-994a-beige-consoles/ has some info and tables members put together of all the variants out there, U.S., E.U., Argentina, et al. Also discussed (can't find the link) was the production change over period ~ August 1983 - basically assembling whatever parts were available as assembly lines switched to the cost-reduced or beige and/or QI. The OS is strictly dependent on GROM 0 (CD2155NL or CD2155ANL) - later on they were not socketed making them more difficult to change out. The monitor port pin variations are at http://www.unige.ch/medecine/nouspikel/ti99/pinouts.htm. The boards were designed to go either way with shunts based on a different crystal, VDP installed 9918A/28A vs 29A, and supplied modulator/adapter. Granted, it's odd with your copyright screen info that you can't use 3rd-party command modules. Of course only the case was serial numbered, so even with week/year production numbers, the parts were so similar the factory or even subsequent users could mix and match boards in cases. My half dozen consoles or so (lost count) are all beige QI, blue power switch stripe, NTSC, non-V2.2 GROM 0 (some socketed) with cases stamped LTA 4083 through 5083 if memory serves.
  12. I haven't tried with Nano or PEB yet ... should have mentioned since they are both in the pictures. Crossing one bridge at a time, minimal hardware only first until stable.😅 Though I am aware once I'm stable, that I'll have to open back up the speech synth and jumper TIPI's 32K "off" since Nano has 32K native and my PEB has a 32K card.
  13. Yes sir. PI Zero W at least that's what it said it came with from store listing. Doug
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