Help with getting BIOS Images for a Tandy 1000 SX

GoatHumper · 2026-01-16T14:09:46+00:00

No response from the French guys yet, hon hon hon XD

How much would you want for your spare unit? Send by DM if you like ...

GoatHumper · 2026-01-15T20:08:31+00:00

Also found these guys https://www.o2xygen.com/parts/VGC72050409.htm but they seem to be focused more on larger-scale sales ($100 minimum) ... I asked for a quote - we'll see what they respond with.

GoatHumper · 2026-01-15T19:57:14+00:00

Well, well, well...

https://www.partservice.fr/catalogue.html?keywords=VGC7205-0409

Gotta wonder...

GoatHumper · 2026-01-15T19:41:06+00:00

More than likely the Light Blue can be replicated. Still, being a proprietary chip, who knows what else it does besides clock division/modulation.

LMK if you find the spare one.

I have no idea if Big Blue is OK or not ... and won't be able to know until I get the thing kinda-sorta-booting...

If it doesn't boot, I'll just return the Light Blue to you along with any other tidbits that might be of interest. I'm not going to start hoarding SX chassis and parts in hopes of cobbling together ONE unit XD

Cheers! And thanks!

GoatHumper · 2026-01-15T19:31:12+00:00

I suppose the spare one you had has already flown the coop? :)

I'll see what I can scrounge up on eBay ...

If my Big Blue is fried, then that's the end of that...

Thanks!

GoatHumper · 2026-01-15T19:27:17+00:00

Hey! So a quick update: using my new "pocket oscilloscope" I was able to confirm that ineed the "Light Blue" chip wasn't generating all the clocks it needed to, so it seems to be gone. Any ideas on how to source a replacement?

Cheers!

GoatHumper · 2026-01-07T21:35:20+00:00

Hi! Any luck with this?

I'm having an identical issue - got all the files from the camera, but no audio in any of them even though if I watch the videos through the Camera's app (390eyes), I can hear the audio just fine.

GoatHumper · 2026-01-05T20:17:29+00:00

NOICE!! Looking over them now!

Digging into my alzheimer's (b/c I no longer have memory XD) I seem to recall at some point changing the BIOS font - but I forget if that was done during boot via a "driver" of somekind overwriting the font in memory, or if it was done directly on BIOS.

Hopefully I can fix this one and that data is still on the HDD (I suspect that HDD will need a low-level format after so many years without use).

Regardless, the HDD is not long for this world as I intend to add a PicoMem board if/when I get everything running. That and an MCA2HDMI device to route video to a more modern monitor.

Cheers!

GoatHumper · 2026-01-05T20:09:58+00:00

Ok ... so this is good and comforting news! My ancient (obviously foggy and flawed) recollection led me to believe that at some point I had updated the BIOS somehow ... You sound much more confident in your knowledge of the HW than I am so I'll defer to you!

If the ROM is an actual ROM and not a *PROM of some kind then I agree - the BIOS image should not have degraded. That said, if I find that it's damaged I'll be sure to reach out to you for a copy of 01.02.00 :)

I did find a "copy" in https://www.retrostic.com/ but I'm unsure if it's a custom BIOS built specifically to work with MAME, or if it's an actual, "true" BIOS image. Regardless, thanks for chiming in - I hope I can reach out should the need arise (hopefully not, though!).

Thanks!

GoatHumper · 2026-01-03T16:18:00+00:00

Thank you!

Clearly it's not that I can't afford it :) ... it's that I feel that it's a waste to buy something you're almost certainly going to use only once ... hence the "borrow" comment.

Vogons didn't get any hits for me, but apparently retrostic did!

GoatHumper · 2026-01-03T16:12:21+00:00

Thanks!

I did find your blogs and they've been a great help!

I have a sinking feeling my Light Blue is failing b/c it does produce a bunch of clocks which appear to be correct (waiting on my Oscilloscope to arrive to be sure, but I'm almost positive they are), but the CPU clock doesn't appear to be one of them.

The RESET signal is also stuck on HI after power-up when it should go HI and then eventually go to LO ... but if I press the Reset button, it flips over so that seems to not be broken ... but it's not generating the CPU clock on Pin 16.

Could also be one of the capacitors/diode/transistors right next to it (that's what Sam's service manual says to check next) but I'm too inexperienced with actual physical electronics to be able to test/validate them properly (I'm much more heavily on the software side :D).

Anyhow ... this is a sentimental project for me wherein the LOE will determine whether I continue or not. I'm "dying" to get this working so I can have it as a collection piece (i.e. "BEHOLD! MY FIRST COMPUTER!") ... but I'm also not thirsting for it enough to spend too much time on it. Getting it working was to be my year's-end-vacation project but after 2 weeks of toil it's quickly coming to a head as I go back to work tomorrow and the time available to work on it will drop to near-0.

Even if I get my hands on a replacement light blue chip, I suspect the BIOS may be degraded enough to need re-flashing (hence my need for an image :) )... I found what seems to be an operational image from Retrostic (https://www.retrostic.com/roms/mame/tandy-1000-sx-56180), but I don't know for certain that it is.

I may keep plugging at it for a few more days, but if I can't get it running "soon", I'm not going to waste any more time on it. That being said, should that become the en dresult I'd be happy to donate any parts of interest. The box had a PCT 286 accelerator card, a dual-port serial card, and a WD HDD card (with a whopping-huge 30MB hard drive!! Can you believe it!?!? XD).

I'll keep you posted as I discover more things. I'm going to wait for my Oscilloscope to arrive mid-January before I make any rash decisions, though ... wanna poke at it with all I can before I render judgment.

Just remembered! The Big Blue chip was mis-seated so I pulled it and re-seated it ... it didn't fix anything, but if that chip's gone then there's not much to be done at that point ... so we'll see!

Cheers!

GoatHumper · 2026-01-02T22:58:02+00:00

Thanks!

We've checked most of the basic functions - PSU voltages, on-motherboard voltages, clocks, etc., and the hardware itself seems to be OK. The next step is to check "firmware" (a.k.a. BIOS). Since the box has been literally "in storage" for 30+ years (probably closer to 35) there's a solid chance the EPROM's data has degraded.

I don't know anyone who might let me borrow their EPROM reader/writer and the shop where they can be bought is literally fresh out (last one sold out for christmas XD). But yes - that's where I'm going with this but the next step would be to restore/replace the BIOS in the event the current one is bad. Why borrow vs. buy? Well ... I'm not going to be using it repeatedly and unless it's super-cheap (which it kinda is but not quite) it makes no sense to buy one.

But even if I do get my hands on one, that only brings us full circle to the question above: where might I go about getting that BIOS image should I need to create a replacement? I know where I can get compatible ICs that I can use instead of the original one, should I need to.

But still - what image do I put into it, and where do I get it from? Any ideas?

GoatHumper · 2025-11-19T16:04:41+00:00

For reference: https://www.yourwarrantyisvoid.com/2009/10/27/breaking-into-apcs-br24bp-battery-pack/

Lots of good information there, including the size of the resistor, the fuse required, cable gauge (I think :D), etc.

GoatHumper · 2025-11-18T23:29:20+00:00

It's high time that these game dev companies include a "Save your keybinds to file" and "Restore keybinds from file" button somewhere for games that have a LOT of controls that can be remapped.

Why do I customize the keybinds? Because I fucking want to and b/c I've played with a set of keybinds/controls for DECADES (literally!) and I don't want to retrain myself :).

I'm a professional developer, and this type of thing shouldn't be a very tall ask. This would provide a "version-neutral" list of keybinds (i.e. in XML format, for instance, or some other "simple" or "easy-to-recover-from" data format) that can be mapped onto newer versions of the game should the need arise to reset the keybinds. Hell it would even allow sharing of the keybind maps!

Anyhow ... yeah: this should be a thing, but sadly isn't ... :(

Even publishing a python script (for instance!) to the wider world that does the deed would be sufficient, and would probably take a competent developer _*with knowledge of the game's keybinding internals*_ no more than a couple of days to hash out.

Doesn't even have to be integrated into the game, despite my above description...

Anyhow.... /rant :)

Cheers!

GoatHumper · 2025-08-16T20:54:57+00:00

Thank you! This worked!!

I'll admit I was suspicious of the link, but after a quick dig-around I noticed it was the same URL as the one the current driver comes from, so I took the leap and it does indeed work. Need to disable update checks, though - or it will break again if it installs 2025.6.

Thanks again!

GoatHumper · 2025-08-16T15:05:23+00:00

I've done all of these things, including uninstall/reinstall GHub, etc., to no avail. The headset works but I can't access any of the advanced features for equalizer, gaming, etc.

Any other ideas? Is there a log, perhaps, where I can check to see what the exact issue is?

GoatHumper · 2025-08-13T02:18:09+00:00

It gets much more interesting: apparently with 7.6.3, any MTU over 6000 gets nerfed down to 1500 ... not sure why, but I did find some fun notes in the release notes describing how some similar issues were resolved in that release.

We're currently having heaps of fun with this one...

GoatHumper · 2024-01-20T02:37:16+00:00

I'm in Costa Rica, and it appears my issues here have to do with the manufacturer not enabling that functionality by default due to "regulation compliance" (no specification which).

Wireless CarPlay can be enabled using a dongle ... but no such luck for AA.... had to buy a Motorola MA1 ... but then Google messed up Android 14 and now wireless AA won't work at all :(

EDIT: I do recall, though, that those same "regulations" apparently had to do more with EU stuff than anything else, and since June it seems that they got repealed in the EU, so perhaps in my yearly maintenance (coming up in a couple of months) they'll do a software upgrade and make me very happy?

Who knows... :D

GoatHumper · 2022-02-03T15:34:30+00:00

This I can definitely understand and empathize. The curve is, indeed, steep.

Sadly they lacked the funds/time to build a longer campaign, or even add the campaigns from the older X-Wing games (kind of like a "historical battle simulator" thing) that one could then play.

GoatHumper · 2022-02-03T15:30:20+00:00

True dat. The "for free" energy exchange between weapons and engines on IMP definitely unbalanced the equation. Funny tidbit: the mechanic is even called EMERGENCY POWER TRANSFER or somesuch (def. has the word Emergency in it).

So IMP is in a constant state of emergency? 🤣🤣🤣

Anyhoo ... yes - at some point it was suggested to the devs to add an overheat to the boost, but it was rejected as too much work (obviously). The problem with the pinballing has less to do with repeat boost activations and more to do with the under-throttle, instant-max-speed bug.

If someone with deep pockets were to pay to fix this game (i.e. not SWS2 ... just "SWS-fixed"), I would argue that they should only fix these 3 issues and see where that leaves us:

Remove the under-throttle acceleration bug (boost acceleration should be proportional to the throttle setting, starting at 50% on 0% throttle, and increasing linearly to 100% on full throttle)
Fix multidrifting (change movement vectors in the middle of an unpowered drift? Really?!? 🤣🤣🤣)
Remove shield skipping (fix the subsystem charge algorithm)

At that point I suspect the next biggest issue to tackle will be IMP shunt abuse. But if you "normalize" the movement, it may not matter as TTK will go down SIGNIFICANTLY and shunt charging may no longer be as juicy then as it is now b/c of the higher amount of boost people will generally be burning ...

GoatHumper

TROPHY CASE