0044 The ZX Spectrum of North America: The Timex Sinclair 2068
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- Опубліковано 18 жов 2022
- On today's video, we have a a Timex Sinclair 2068, also known as the ZX Spectrum of North America. It's a neat machine and a bit uncommon.
-- Video Links
Timex Sinclair 2068 Service Manual:
www.polylith.com/~brendan/Clas...
Adrian's Digital Basement Merch store:
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Adrian's Digital Basement (Main Channel)
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-- Tools
Deoxit D5:
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O-Ring Pick Set: (I use these to lift chips off boards)
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Elenco Electronics LP-560 Logic Probe:
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Hakko FR301 Desoldering Iron:
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Rigol DS1054Z Four Channel Oscilloscope:
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Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
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TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
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TS100 Soldering Iron:
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EEVBlog 121GW Multimeter:
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DSLogic Basic Logic Analyzer:
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Magnetic Screw Holder:
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Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
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RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
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Plato (Clone) Side Cutters: (order five)
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Heat Sinks:
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Little squeezy bottles: (available elsewhere too)
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--- Links
My GitHub repository:
github.com/misterblack1?tab=r...
Commodore Computer Club / Vancouver, WA - Portland, OR - PDX Commodore Users Group
www.commodorecomputerclub.com/
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
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I have chatted with someone familiar with this machine, and it definitely should color (and a color burst.) There will be a future repair video where I dig into what might be wrong with this machine to get it fully working!
By the by, I just got my 2068 turned on, and it seems you have the spectrum rom in there, mine shows a 1983 Timex Computer Corp copyright line when it is turned on.
If possible, I'd also love to see a video about upgrading the internal RAM on a ZX81 / TS1000. There are several ways to do this, all fairly easy, but I think they'd make an interesting video.
I wonder if it's doing something odd like 60hz PAL - you'd have a different colour signal then. That extra bodge board above the video out has me wondering.. did the owner mod it to also do PAL 50hz and you only have half the mod left?
Games do run faster in 60hz - you can toggle scan rates on the Spectrum Next and not only do the games change speed, the pitch of the music (often generated under interrupt) change also. Few games were written for the US market because as you mentioned it wasn't popular there.
9v centre negative is exactly what I'd expect.. good call on checking the polarity first, since centre negative is so unusual. There's no protection on the circuit so connecting them backwards would cause the magic smoke to escape.
Well, it says “Personal Color Computer” on the lower left side of the case, so I think there should be some color… 😅
Adrian, Modern Vintage Gamer on YT did a video on the 2068, His unit had the same bodge wiring that yours has on the user port and VLSI chip. Archive org has the user manual, page 6 shows the side ports are joysticks in the text.
FYI: do not buy the book "The Essential Guide to Timex/Sinclair Home Computers". It's 90% a boring BASIC tutorial and 10% a reprint of the TS1000's manual. Its "special section on the Timex/Sinclair 2000" is vaporware, and sheds absolutely no light on the Americanized version of the ZX Spectrum that was shown at CES but never produced.
My mom worked for Timex in the 1980s at a distribution center in North Little Rock, AR. The facility had a PDP-11 installed that was never used. She and her team opened up the manuals and learned how to get it bootstrapped and load the custom inventory software needed to automate the distribution instead of relying on all paper ledgers. The company remembered this several years later and gave all of her team that still worked there free 2068s. At the time we had an Atari 800 and dad used both a C128 and an XT clone which ran AutoCAD.
I remember mom buying a little portable TV and setting up her 2068 at her rolltop desk with the TV perched on the top shelf at roughly eye level. She used that thing into the early 1990s when it went out completely. Dad bought her a 386 DOS laptop from Zenith and she used it but even years later talked about how much she missed her "Timex PC".
What amazing stories - thank you for sharing them with us! 🙂
That little computer meant a lot.
The Sinclair ZX80, released in 1980, was a machine of its time.
The Sinclair ZX81, released in 1981, was a machine of its time.
The Timex Sinclair 2068, released in 1983, was a machine 85 years before its time!
Nice!
@@horusfalcon there was a variant unipolbrit komputer 2086, that csme out in 1986 !!
LOL
@@andygozzo72 Unipolbrit 2086 was interesting mutation
For some reason this wasn't funny to me at all, but by the time I got to the last line, I had a "guffaw"!
Those bodge wires are factory. The "Upside down" PCB is also factory. The T/S 2068 was really not fully baked when it was released. Timex needed to get the computer out for the Christmas 1983 season so they did what they needed to do to get a working system out to consumers. The "Hissing" noise is from the switching regulator and there is an OP-Amp inside the switching regulator chip that picks up the switching regulator frequency and amplifies it through the speaker. I bought one of these machines (actually pre-ordered it) back in 1983 when I was 15 Years Old. I am very familiar with this system and we even have monthly Zoom meetings. you can see old meetings I believe on the Timex Sinclair Fans UA-cam channel.
Also, you need at least 14V for the 12V linear regulator to regulate properly and the 12V is used for the color circuits.
@@mileselectronicsstudio7316 came to the comments to say just that! The voltage needs to be higher to get color.
You mean www.youtube.com/@timexsinclairfans right?
Wow! This is fun. I just got my TS2068 out of its box a few weeks ago!
Here's some info for you:
1. The thick white bodge wires are from the factory. Some of the others were added by the former owner.
2. You aren't running the Timex ROM, but the ZX Spectrum ROM. If you have the Timex ROM, you get TWO copyright lines at bootup. I think you're missing the Timex ROM, which would have gone in the other socket of the add-on board.
3. You need the voltage up around 15V for some of the circuits to work.
4. The Russell company made lots of ZX81/TS1000/ZX Spectrum/TS2068 add ons in the 1980s. There would have been a reed switch under that label and a button magnet that you'd slide back and forth to switch between them.
5. I suspect the little add-in board near the edge connector is a video adapter board. Unlike the ZX Spectrum, the TS2068 had RGB signals available on the edge connector (TTL RGB). This could drive a CGA-type monitor. But, the Hsync and Vsync signals are NOT available separately. You have to extract them from the composite video with a small circuit. The technical reference manual that you had up on your phone discusses this and includes the recommended circuit. However, several people sold circuits that worked better for this purpose and used ICs instead of discrete transistors. Another odd omission is the I signal. Although the TS2068 will show 16 colors via composite and RF, there's no way to get the I signal and feed it to an RGBI monitor. So, an RGB monitor will give a much nicer picture but only 8 colors. Incidentally, the interference that you see on the composite signal is normal. The crude switching regulator makes a ton of noise. Many current TS2068 owners replace the power section of their computer with a modern regulator to clean up the composite video.
Looking forward to seeing what you do with the TS2068 next! And hang in there. Once you get the knack of the keyboard, you can type code VERY fast.
It's a switching regulator? That explains the hissing.
@@melkiorwiseman5234 Yes, the 5V is a rather crude switching regulator. The 12V is an undersized 78L12 linear regulator.
The ZX81 and the Spectrum were hugely popular in Australia and New Zealand, too.
My first computer was a TS-1000 and I remember a brochure in the box that advertised the 2068, and I wanted one so bad! Well, didn't happen, got an Atari 600XL and was as happy as could be.
Actually, they weren't the same hardware. The TS2068 had extra video modes, a real sound chip, joystick ports, a cartridge port that was a separate memory bank. The edge connector was also different. It even had CGA compatible RGB on the edge connector.
The 50/60 Hz differences were obvious. Nearly all software used the vertical blank timer for timing. So Sinclair software would run a bit faster on the TS2068. Even when using a genuine 48K Spectrum ROM, it was still only 96% compatible.
The bodges and the daughter board are factory. The TS2068 had two ROM chips. One was in the primary memory bank (16K) and one was bank selected in (8K) the EX-ROM bank. The cartridge also was bank selected. The TS2068 had advanced bank selection and the 16/48K ZX Spectrum did not. The ROM switcher board only selected the ROM in the HOME bank.
The hissing is normal.
You need to burn a TS2068 HOME ROM to use the computer's actual ROM which is an enhanced version (and why Spectrum software is not compatible).
This was the first computer I owned. I made expansions and improved the OS using the bank selection logic.
Also, the Timex Technical Manual is available for download. Yes, it's color and should have colorburst. The joysticks were proprietary to the Timex. Sinclair joystick assignment is not compatible.
As you say, the hissing was normal, with the original power supply (which was indeed 15 volts) -- but maybe it actually makes sense to give it less voltage, and maybe that really does kill the hiss, as well as the screen noise, as Adrian seems to have found? I never saw that experimented with back in the day, but I do know that upgrading the voltage regulator was a common mod.
@@wmcbrine upgrading to what?
@@wmcbrine what does it do if you change it? I have one of these machines.
@@blackterminal I haven't done the mod. Read the article, you'll know as much as I do.
The issue with it, it was meant to be a rock bottom priced computer, the only reason it sold so well, at least here in England, as despite how unreliable they were, they were half the price of their nearest competitor.
Even later Spectrum revisions(such as the later models with built in tape drive) all stuck to this principle. In the late '80s they were still stocked and sold in high enough numbers in bargain stores for like £50.
It's so nice to know the history of ownership and that that was the first machine someone used, everyone's first machine is like a first love. I think it's great that you're preserving computing history, both the hardware and the knowledge.
Fun fact: The Timex Sinclair 2068 actually had 2 clones:
-The Timex Computer 2068, sold in Portugal
-The Unipolbrit Komputer 2086, a Polish clone
The TS2068 has additional graphics modes that the ZX Spectrum does not have. The AY chip is mapped differently from a ZX Spectrum. There is AY support in the BASIC ROM. You probably want the TS2086 ROM as well.
I don't know much about the 2068 itself, but that's definitely the original Spectrum ROM you have there. The Timex ROM shows a “© 1983 TImex Computer Corp” message under the Sinclair one.
Also, as others have mentioned, the hardware isn't identical. The Timex has some (very interesting) extra graphics modes which are supported in BASIC, but only in its own ROM. Also, the GI sound chip is on different I/O ports to the one in the 128K Spectrums, so any Speccy software that uses it won't work. I believe the joystick ports are also incompatible with any of the Spectrum standards, but don't take that as gospel.
ZX Spectrums were immensely popular in the rest of Europe too, especially in Greece and Spain. Also plenty of clones behind the iron curtain too.
This same model with some modifications for PAL, was produced in Portugal and I had one. It was the TC 2068 instead of TS 2068.
@@fernandobernardo6324 Strange, as the original British ZX Spectrum should have been just fine in Portugal. France may have needed a special SECAM model though.
@@johndododoe1411 Indeed, but Timex Portugal decided to make some changes to that model and create another one TC2048 and they were produced here. These models were exported to some countries like Poland, where many spectrums were in fact Timex machines.
@@johndododoe1411 French Spectrums came with a SECAM adapter that plugs into the edge connector.
@@fernandobernardo6324 Timex of Portugal were allowed by Sinclair to serve markets not covered by Sinclair: Portugal, Poland, Chile and Argentina. In Poland one can find the Timex Computer 2048 and the Unipolbrit 2086 (which is a modified Timex Computer 2068)
This was my first computer, so many memories, I was going to hack the world with that machine what set me in my actual career as a programmer, I remember clearly the hissing but never knew what did produced It.
So sorry the machine didn't came with the manual, BEST MANUAL EVER!!!
I think VR stands for "variable resistor" on the board not voltage regulator so they don't necessarily control supply voltages. :) love your videos BTW, thanks for creating them! :)
UK ZX Spectrum's were also manufactured by Timex at their factory in Dundee, Scotland. 5.5 million units were sold across all versions of the system. My first computer was a ZX81.
I think Noel from Noel's retro lab created a diagnosic rom for the spectrum last year, you might be able to download that to test it out further.
Cool. Just picked up one of those TS2068 myself and haven't looked at it yet. Looking forward to your future videos on it.
From memory as an old Spectrum owner.
The three pots you pointed out are to adjust video timing, early Spectrums needed tweaking to get a good stable colour picture. Worth trying to sort out your colour problems.
The ROM probably contains both Sinclair and Timex code. The lifted pin and bodge wire are acting as a bank switch for the lowest 16K of memory.
I love these retro computer videos. Had a C64 back in the day... but did pick up a Timex Sinclair 1000 at Kmart... on clearance... for 50 whole cents! Really!
@Adrian: The TS2068 , the American version of Spectrum, had The General Instruments Sound Chip AY-3-8912. The Spectrum ROM could be put on a small card in the cartridge slot, and then the machine ran as Spectrum. The buses between Spectrum and TS2068 were different. It needed an adapter, named a Twister (I was the designer) which enabled one to run Spectrum hardware like micro drives, etc. With the twister one could run 3” floppy system (designed by Timex Portugal) as well as other British floppy systems on the TS2068. The Portuguese made 3” floppy system ran both CPM, as well as rudimentary Timex DOS. The Portuguese made Timex 2068 was nicer., with same GI sound chip. It looked exactly like TS2068, had the Motorola MC1377 providing RGB signals on the output bus. Here is the schematic for TC2068:
timex.comboios.info/Timex/tc2068squematic.jpg
The Spectrum emulator supplied by Timex Portugal was on a cartridge, and made the machine fully Spectrum compatible. That same cartridge, with a very minor circuit modification (which I made, and was marketed by Zebra Systems) made a good Spectrum emulator on the TIMEX TS2068, using a bank-switching command.
There were also Brazilian made Spectrum ripoff called TK90X (Sir Clive sued the Brazilians, but lost). It is a good machine with RGB out. I have both TC2068, and TK90x.
There were also Soviet knockoffs, Polish knockoffs and I think Czech copies. The Soviet machine is on the UA-cam.
To facilitate troubleshooting here is a link to the Technical Manual for TS2068. The schematic is at the end of the manual: ia801307.us.archive.org/8/items/TimexSinclair2068Manuals/TimexSinclair2068_TechnicalManual.pdf. Have fun 😁.
I also had prepared a comparative ROM Atlas, comparing Spectrum and TS2068 routines and usage. The Atlas was published in two user monthly newsletters at the time (August 1986).
Now I will watch the video, and if need be will comment later.
This was my very first computer. The keyboard was horrible, but I have to say, if you did a lot of BASIC programming on until the key combinations became natural - you could actually code faster than someone who had to type every keystroke of every keyword. In a sense, this keyboard is the godfather of autocomplete. LOL
If you compare to PC keyboards, the 2065's was pretty bad. However, if you started with a ZX81/TS1000 the 2065 keyboard was a godsend!
In a lot of BASICs, you could abbreviate keywords. Atari 8-bit BASIC, which I used a lot (username relevant) would let you enter, for example, "SE." instead of "SETCOLOR" (you'd get the full word on LIST, er, L.).
Absolutely beautiful version of the ZX. Sinclair must have been proud.
So cool this classic 8 bit computers. I have my eye on an Gradiente MSX 1.1 around here. Thanks for the videos. With all politic turmoil around here they are so relaxing and entertaining!
There is an european version, the Timex Computer 2068. Some may call it a clone but in fact it is the same computer, designed by Timex Portugal with some hardware differences. It uses the same ULA and ROM, the big differences were the rear edge connector which is ZX Spectrum compatible (the TS2068's edge connector is ZX81/TS1000 compatible, and can be made ZX Spectrum compatible with a Twister board), the cartridge port can receive thicker cartridges, and it uses 9V DC center-negative power supply like the ZX Spectrum (in fact, the PSUs are compatible). Also the TC2068 was sold with a ZX Spectrum compatibility cartridge (Emulator Cartridge), which basically when inserted disables the internal ROM and replaces it with a ZX Spectrum ROM, increasing substantially the compatibility with most ZX Spectrum software.
The TC2068 was made like this to be compatible with lots of peripherals and software already existing in Europe, that don't exist in the US since the ZX Spectrum was never released there.
Timex Portugal also launched the TC2048, a ZX Spectrum 48k compatible, that uses same ULA of TS/TC2068 but it's more compatible with the ZX Spectrum than the TC2068 with the Emulator Cartridge. It has a slightly modified Spectrum ROM and it retains the hi res modes of the TS/TC2068, and a Kempston compatible joystick port. Usually the compatibility problems arise when software expects a true Spectrum ROM and with the audio generation (no sound in some games). The TC2048 is unrelated with the canceled TS2048 Timex US project.
The Unipolbrit Komputer 2086 was a modification of the TC2068 manufactured on Poland under license of Timex Portugal. For almost all purposes it is a TC2068, with some hardware changes. The ROMs were slightly modified and one of the joystick ports was replaced by a Centronics port.
More information about Timex computers, clones (TS1000 compatible) and peripherals is available on this site: timex.comboios.info/PT/home.html
I am very interested in seeing more on this. I had a Z81. I had a tape player and RAM expansion pack. Was one of the very first computers I owned. I got it at a garage sale. I learn to program on it. Though it was hard to use. It made programming everything else seem easy after that. I never had the printer. Never even seen one ever other than in pictures. I thank had it before my Texas Instruments 99/4a home computer I keep on thinking was my first. I wanted a Timex Sinclair 2068. I never could find one I could afford at the time.
I remember seeing a ZedX for sale new in the store, and I waited for my turn with the display model. I had the cash in my pocket to buy it, but after 10 minutes with that keyboard I bought a Vic 20 instead.
I had a Timex Sinclair 1500 at one time (dad found it at a "resale shop" many years ago). The case looked more like a silver-and-beige ZX Spectrum, although I understand it was more of an upscaled TS 1000. Even had a matching thermal printer with it. It went missing years ago, I suspect I lost it in a house fire, along with my 3 TS100 machines and their accessories.
Never actually *used* any of them, they were just in the machines I was collecting at the time.
The TS1500 is a ZX81 in a Spectrum case with 16K internal RAM. Oh, and the case is tweaked ever so slightly to sort of match the styling of the 2068. It was a weird relic of Timex's original plans to bring the Spectrum to the U.S., before they went with the more advanced 2068.
I love this computer! I am sure I am not the only one that got some TG-16 vibes with that port in the front
That form factor reminds me of two computers launched in Brazil in the '80s, the CP200 (compatible with the ZX81) and the CP400 (compatible with the CoCO 2).
More like the first version of the CP-400, with the "mini" keys. But the color scheme (silver with black lines) reminds me of the MC-1000
Conectiva former employees detected over here too...
Neat video! My only real awareness of the Timex Sinclair back in the day came from the fact that there were usually (or often, at least) Sinclair variants of the Basic type-in programs that were published in many of the magazines and books of the time.
I think I can remember seeing some version of the Sinclair for sale on clearance at a department store long after it would have been market relevant, perhaps about 1990 or so. I didn't bite.
I had a Timex 2048, it was smaller ( no card port ) , it also had 2 joystick ports and it had RF for ntsc or pal.
I remember that it had on the manual a code that open some eprom that was able to be write from the basic, but I do not remember any eprom on the main board.
It use a 9V - 1 Amp power brick.
From what I remember did not had any "extra" boards on the main board.
I had to repair my when it blow up a cap.
It was a strong (like a tank) machine, besides the cap nothing more got damage.
Good video, 😉
What a good memory... This was my first computer! I recall playing in commando with a friend of mine for a whole afternoon and in the end by accident he pushed the on/off switch on the side of the machine... Damn, what a great test to the resistance of that machine this was... 😅😅👀
"playing in commando" - you had no underwear on? lol . What a great typo. or maybe i am wierd.
@@TheSudsy Commando was a spectrum game from elite released in 1985. It was one of my favorites
So cool to see this on the channel, and that it sort of works!
Those are definitely joystick ports on each side, but I haven’t the faintest idea of what joystick protocol they talk for the software.
I wonder what happened to the other ROM? I definitely remember using that machine in ZX Spectrum mode a few times, but it was very wonky.
My brother was somehow a Sinclair authorized dealer in the US for a while in the early 1980s. I remember he had a Sinclair QL, which alas was stolen from his house in the 1990s.
Now that I know this uses a 9V center negative power supply, I’ll have to dig out my TS2068 (I have an unmodified one we got when they were being blown out for real cheap back in the day) and see if it works.
They’re Atari compatible.
I have recently picked one of these up off ebay, but I didn't really get much of a chance to mess around with it. Seemed like a very cool machine, from a historical perspective.
Well, it does say “Personal Color Computer” on the front of the case, at the lower left. 😊
I was thinking the same 😂
I had one of those things in 1989. It came with a couple of differently styled digital joysticks of a design which I believe predates the Atari VCS. They were more styled like a mushroom where you held the stalk and they had a rounded triangular cap. They may have had rotation and two buttons in addition to up-down-left-right. I recall the same motherboard bodge wires/components and that little green upside-down bodge PCB as well.
As far as I remember, TS2068 had a ZX Spectrum "emulation" cartridge, which supposedly was supplied with the computer (at least its Polish version - Unipolbrit 2086 was). There was also TC2048, which was much more ZX Spectrum compatible.
Correct. Same in Portugal.
Iirc it was an extra and rare, dont know for sure though
The US Spectrum cartridges for this was very expensive and is now insanely rare. It certainly did not come with the machine.
i have a tc2048 but not yet working correctly,
Are those Soviet era clones?
My first computer was a ZX Spectrum +2. Very versatile.
This looks like a very neat machine. Please do a follow up soon! :)
Great video and you are very knowledgeable about the Spectrum these days, Kudos. It did not take long to get used to entering basic programs and the less keystrokes you had to enter on the rubber keyboard the better. The Spectrum keyboard is way better than the ZX-81 while still being terrible.
I know someone who has a PAL 2068 as they were sold in Portugal. They also have the rare Spectrum BIOS cartridge for it, so you could natively run Spectrum software on it
They were sold and made in Portugal.
I loved my 48k ZX Spectrum ❤❤
If that hole in the back is near the keyboard connector, it may be he had an external keyboard at some point.
That was quite common over here with the ‘81 and Speccy, where people had ribbon cables out to a more robust keyboard 👍
yeah that has to be it. just soldered onto the back side of the connector
En Argentina toda la línea Sinclair fue muy famosa junto a los Commodore 64, Tuve una TS2068 y era espectacular aunque cargar programas desde la casetera era un dolor de cabeza.
Hi Adrian, I may have mentioned this before, this was my second computer (T/s1000 the first) and the reason this failed was lack of software I think. I didn’t know then at 13-14 years old that the reason I couldn’t run spectrum stuff and had to wait for ports was because Times decided to make it their own rather than just make it spectrum compatible. I learned basic and machine code on it. I also created software and sold it on cassette via mail order back then too, database stuff and the like. My favorite games on it were “Fighter Pilot” and “Tomahawk” sims. Tomahawk I had to wait 9 months for them to port to the 2068 from the spectrum. The nice thing about those games is that you could use two joysticks. For Fighter Pilot you used the left stick for throttle/rudder and the right stick for aerelons, elevator, guns. Tomahawk was collective for the left stick and cyclic/weapons for right. The sound generator was really neat on it if I remember. Well enjoyed the video and wish I could have done that to my 2068 back then!
Great video. I'm hoping you get round to bringing the Timex back to its full glory soon, as it's an unusual machine. Obviously, here in the UK, we didn't get these, but I can't understand why Timex messed around with the hardware and ROMs, making it largely incompatible with Speccy software and hardware add-ons. The major attraction of the Speccy were it's low price and huge software library. Timex should have stuck to making watches. 😁
timex dundee made many if not all of the sinclair machines in the uk anyway 😉
I seen the power supply. It a DVE power supply. Model No. DV-141A. Input: 120V AC 60Hz 26W. Output: 15V DC 1A
that ZX Spectrum looks like how I remember seeing it as a kid.
The 2068 has a brown in its colour palette along with a black whereas the ZX Speccy had 2 blacks so there can be problems translating the correct colours in ZX Spectrum games when installing the ZX Spectrum ROM into the 2068. A nice looking machine we never got in the UK.
I think Spectrum is prettier. And it's rubber membrane keyboard was still a major upgrade from the flat membrane keyboard on the famously cheap ZX81.
My dad had a TS 2068. I had the TS 1500 that looks like a black-and-silver ZX Spectrum case but it's mostly a ZX81 inside, and the thermal printer. (all on clearance after Timex gave up) I never tried to play games on the TS 1500 - it would not have been able to compete with our Atari or the Apple II I played Ultima on at school.
Looks like that plastic post and brass nut, along with the thermal pad that fell out of the case early on, may have been for heat sinking the voltage regulator on the far left side of the motherboard.
Defaulting to Celsius? Your Canadian is coming out. lol
25:35 it's possible that the computer was operated on a monochrome monitor. The color burst would interfere there, since the signal is then interpreted as "dots". Black and white TVs had a color trap for this, which filtered out the burst. The disadvantage was that the sharpness went down.
I am actually going to a furniture store that is in the old Timex factory in Dundee Scotland where these were made tomorrow lol. Guy at our work used to do QC on these at the factory.
NCR also being in Dundee
I'm from buenos aires, i had it in the early 1990s, i remember attaching it to the antenna input of the Philips Trendset tv at home and struggle with v-scroll lock despite being a colour tv made in the 1980s.
What i still would like to know if Trendset TV's from Philips were created by Philips of the Netherlands or they were conceived in Brazil for South America..
Oh I really enjoyed digging into this computer a few years back. First, you are probably not getting color because you are only using 9V. The video section of the computer need +12V and that is generated by a linear regulator off the +15V input, so you are severally under powering that section of the circuit. This computer was supposedly desperately rushed out to the market and the PCB design really shows. The little PCB you saw at the top of the computer as well as the flying wires are all how it was shipped. The noise you are hearing is because the switching regulator runs at audio frequency (the inductor likes to ring at the switching frequency) AND the speaker is driven from the op-amp on the switching regulator itself! The ULA (SCLD) has a bug when they ported from PAL to NTSC and the color reference is incorrect, resulting in wrong color. The video output is noisy and the expansion port is not pin compatible with the Spectrum, the sound chip is mapped differently from the Spectrum (to be fair, this computer implemented this before the Spectrum) and the joystick does not follow any of the regular Spectrum standard. It was really fun converting mine into a machine with switchable rom, improved power supply, S-video output, fixing the color, re-mapping the sound chip and joystick when in spectrum rom mode to be Spectrum compatible. Drop me a note if you want any of the technical details.
There were game cartridges for the ZX Spectrum but you needed the optional "Interface 2" expansion which added the cartridge slot and joystick ports. They never really took off as the cartridges were more expensive to produce than cassette tapes and the Interface 2 was not that common as there were other cheaper joystick interfaces like the Kemptston. Even in the later versions of the Spectrum that included joystick ports as standard the external Kempston interface was more common for game support as it was well established.
Also the game cartridges could only contain 16K of data, whereas on a fully expanded Spectrum you could load 48K.
If I had to guess, the "monitor" output was intended for use with a monochrome monitor, which would display an annoying pinstripe effect if fed a color signal. Color is probably available on the RF modulator output.
nice aesthetic music choice
Adrian, could that white post with the brass nut on it be the "guts" of the color trim capacitor?
I'm amazed that after 3 decades, there is NO polarity standard for barrel connectors!
And no voltage / current / size standard - or even whether it is AC or DC. I wonder how much equipment has been trashed by people just plugging in any nearby supply that happens to fit - either accidentally or through lack of knowledge.
My family (we're American) briefly had a Sinclair ZX80 that my dad got second-hand when I was about four years old. I don't remember it being branded as Timex, but I was so young so it could've been Timex-branded and I just don't remember it. From what I can remember, none of us could figure out how to do anything with it, and we later (not sure how much later) got a Commodore 64 from K-Mart.
nice, i picked one of these up posted from the usa (i'm in the uk) in the mid 2000s , very uncommon to find them here, not surprisingly,
You can use a fiber glass pen and push in the dc power jack and 'twiddle it around' to buff up the centre pin.
You can also wrap a small strip of sandpaper around a toothpick or very small screwdriver.
Lol! I remember asking my dad why this "marker pen (sharpie)" isn't working as a kid back in the early 1980's... He wasn't too happy and then showed me what it was for and to not touch it... 💯hehe
Timex / Sinclair computers made the user do the job of tokenizing BASIC commands for the computer! Still, a lot of good memories, and the BASIC had some more sophisticated commands than the C64 (after I accidentally killed my 2068 I later owned a C128, then more recently got another working 2068). Can confirm my original 2068 power supply is 15VDC, 1A, center negative (good job getting the polarity right without a reference).
The Spectrum in was later upgraded to 128K from 1985 with a brand new ZX BASIC which did away with the annoying command key typing system and had more commands the utilised the AY-3-8912 sound chip the 128K Spectrums were using. After Sinclair's computer division was sold to Amstrad in 1985 the Amstrad designed Spectrum +2/+2A/+2B resembled Amstrad's CPC464 which had a built in cassette datacorder when the Spectrum +3 was released in 1987 it used Hitachi CF2 3" disks which the Amstrad PCW, CPC664 & 6128 were also using the Spectrum had another BASIC update called +3 BASIC which utilised CP/M
+3 BASIC doesn't have much of anything to do with CP/M so far as I know, but Locomotive did produce a version of CP/M that could run on the +3
I wonder if the cutout on the base under the keyboard connector was done so that an external keyboard could be bodged in.
There is a cartridge for this for swapping the ROMs. I'm building some FujiNet boards for the Coleco Adam, very fun device.
Hey Adrian! I didn't know you went to High School down in that area. Loyola High School myself, not too far from there.. ;-) Small world..
the 'half duff' 64k chips werent just used by sinclair, they were officially sold by the manufacturers under unique type numbers and had 4 'variations' of the duff bank, either duff row or duff column, and each of those either high or low bit duff , one manufacturer sold duff row ones, the other duff column ones,
Can't wait for the next part. Are you sure it's not just the Retro Tank making the signal monochrome?
There is a DiagROM for the Spectrum which you can find free online. It does require a small mod but not sure about the TS2068. You burn it to a 27C128 EPROM and it does require a small resistor/diode mod. (note that whenever I try to give the name of the website the DiagROM is from, UA-cam deletes this message 😕)
Hi Adrian, the only ZX Speccy I have is the Soviet/Ukraine Made Robik computer. I have the original box, Diagrams in Russian, and I have opened it up totally amazing insides. Maybe you will tackle one of these if you ever get one. John :-)
i have one of those, not yet got it working, the internal regulator has been removed and some of the keys stick down
the Russian version sounds like an adventure.
I’m pretty sure my dad had one of these when he was a kid!
It should have color. You were looking at the video signal, but there should be two color difference signals as well that are combined to a composite signal before it enters the RF modulator. At least that's how (or similar) it's done on the original ZX Spectrum.
The mysterious plastic piece rattling around may have been part of an RF socket or connection handling the color subcarrier. Or it may have been a stalk for a case sceew.
Spectrums were popular in the UK because at the time, most people were POOR. A new 48k spectrum could be bought for £180 whereas the 64 retailed at £299. This is also the reason C64 disk drives never really took off here.
We still are :-)
Bet that hissing was the transformer right there near that inductor at the back left.
Also, a good trick for finding the location of noises is to use a length of tubing, stick on in your ear, and wave the other end around where you're searching.
The hissing comes from the op amp, which is on the same chip as the switching 5V power supply.
I still have my dad's Timex Sinclair 1000, which is pretty old at this point. I'm pretty sure it doesn't work and I'm afraid to even try 🤣. It even has a RAM expander.
15:46: I'd be curious to know whether it would have been necessary to remove the ROMSWITCH daughterboard. Maybe it would have still worked, so long as it was switched the right way. Though I do realise the point in simplifying first and removing it for troubleshooting purposes. Seems like a lot of work for that though.
The cassette connection on many of these old machines were mono audio cables to whatever old mono cassette recorder you had around, as long as it wasn't complete garbage. Nothing brand specific like the Commodore Datasette. The user would be instructed to press play or record at the right time. Some fancier machines had a smaller 2.5mm jack for controlling the pause function via the input normally connected to a button on the microphone. Of cause these days it would connect to some other audio storage as modern cassette drives use the same awful cheap mechanism with very few quality options such as a slightly heavier flywheel.
It wasn't just that Spectrum keyboards were bad. It's that they wanted you to feel bad too. (Although I'm seriously impressed that Adrian managed to find E mode by sheer trial and error! You get to this by pressing both shift keys simultaneously, which is not intuitive!)
This is why I am glad I have the Spectrum + 48k model - all those weird mode combinations were expanded into their own keys. Plus, there were plastic keys on top of the membrane that make typing less erratic. I'm currently learning BASIC on my little Spectrum (I have bad fingers at the moment so pressing one key per command is really attractive)
[the only real difference with the + 48k model was the case and keyboard, to the point where Sinclair made case-upgrade kits for £20 and would fit the thing for you if you posted your Spectrum in with a £30 cheque or postal order]
I have the one from my youth sitting on the shelf. I also bought the ZX spectrum rom. Would love to get it running again but the power pack is missing.
I got mine working with a generic 6-12 volt multi-tip power supply I got in Walmart. Just make sure it’s set to 9 or 12 V and the tip is set for center positive.
Standard ZX Spectrum uses 12 Volt for color (I should say colour) generation chip, and it generates it (12V) alongside the -5V for RAM, from the little step-up converter based on a choke you heard hissing at you.
And I remember my Spectrum + had the AC 9V adapter. Maybe if you use the DC this thing can not start 12V ???
I have one of these. As a Commodore guy used to just typing the commands, I agree the the keyboard is murder. Mine makes the hissing noise as well, seems to come from the square shaped inductor. I encased mine in clear silicone sealant and that made it quieter, but not totally silent. I'd be curious to know if there is a modern substitute component. The power supply mine came with indicates it outputs 15 volts, I believe it is factory original. My screen says on two separate lines "1982 Sinclair Research Ltd' and "1983 Timex Computer Corp" so I wonder a little bit about the rom you have. I see on ebay a cartridge for the ZX Spectrum rom, may experiment with that at some point. Mine does output color. For quick test, press shift-b and then pick a number - this will change the border color.
Hissing or buzzing TV is normal on ZX Spectrum, as the sound was coming from the speaker in computer. Sound on TV must be muted or set to zero. Also, "baseline" ZX Spectrum 48K (including "plus" version) is the main and most massively produced-16K version was soon dropped in favor of 48K, and those with bad RAM chips are also early "issued" mainboards, (Sinclair used the word "issue" instead of "version" "v."or "ver." for motherboard revision).
It was hugely popular in Europe, and when past its prime there (late 80's, early 90's) it became popular in former Eastern Europe, Belarus, Ukraine and Russia. It got new DOS and was reverse-engineered to the point that ULA chip was "de-constructed" into discrete components and built in that form!
The parts falling out was for the voltage regulator, check if the other brass nut is shorting something under the pcb. hissing noise???
It’s only confusing because it’s new to you. Once you understand the layout you can really fly. I also thought there should be a Timex copyright message if your running off a Timex rom.
Yeah, seeing only the Sinclair notice indicates that he's running the Spectrum ROM.
Looking at the rom switcher mod, I think the reed switch is still there, in that clear heat shrink. Seems it may had been damaged (wire ripped off on one side?) when the other rom was removed.
That was my first computer the ts 2068 !! Wow
It should output color on the composite out
I can see the burst signal on the scope right after the black reference, but it is waay too small
Mine had the mod to run as spectrum otherwise games won't run (I didn't do the mod, I was a kid I had no idea what a logic gate was hehe) little will I know back then that digital electronics will become my life!
Of my speccy friends, almost all hated the "eraser" keyboard, but the split was pretty even when it came to coding basic on the speccy some loved it, some couldn't stand it. I never owned one, so I was eternally frustrated by it.
The 'bodge' wires are original. They are part of an attempt to eliminate interference caused by power supply ripple and feedthrough from digital to analog signals inside the ULA. It doesn't work very well. I replaced the switching power supply with a small dc/dc module, removed the video ground bodge and soldered thick copper wires between the ULA ground, composite output, and rf modulator. It's better now, but not perfect. Investigations continue...
I had a Spectrum 48K (replaced a lovely TRS-80 M1 L2) and the power supply was 9V.
9vdc, center negative iirc (on most 48k Specs)
I don't know if you have had the answer yet, but from what I remember from the ZX 48K the joystick ports were 9 pin D-shaped port like the old pc mice.
Stock ZX Spectrums used 9v DC at 1.4A on a terrible linear regulator that gave the 64's brick a run for it's money in terms of melting and blowing up. Original ZX's are also -extremely- hissy and noisy just generally - someone brighter than me can tell you why, but I suspect it's a result of the cost-saving design
That is the ZX spectrum rom in it, the Timex Sinclair rom starts with a 2nd line timex sinclair copyright notice below the Sinclair one
GAK! I just looked up motherboard images and those bodge wires are FACTORY stock. Such beautiful Sinclair hardware. /s
Timex hardware. The original Spectrum has a quite clean motherboard with no bodges at all I think.
@@MQsto There's a lot of revisions of the Sinclair, some of which are cleaner than others.
retro man cave did a video on that model and he did do a rom swap as well. I do have a timex sinclar 1500 the one in a zx spectrum case along with a few 1000's
That was my second computer after the TS1000 (US ZX81) and was better than the speccy of the time by a lot. Hm its running the speccy rom instead of the timex one. That means compatibility, but none of the more advanced features of the 2068 will be working. Composite is color. Atari standard joysticks (IIRC), Clock is a bit faster, but blanking time shorter, so about a wash in speed. Also has AY sound and extended color modes. To see all that stuff working ,you need to take out that added rom board. Should boot with two lines of text - sinclair and timex
Back in the day, Spectrum programmers got the machine to do things that seemed almost impossible to do with the hardware. I can imagine that there may be programs/games that will find the 60Hz framerate of the US variant a problem. In the UK version, there is an interrupt generated at 50Hz at the start of every frame. I recall writing a program that would carefully arrange to rewrite the attributes data very fast (in fact it was only the first 24(or maybe 20) characters of each 32 character line) in such a way that each scan line (8 per character) could be in a different colour (more precisely have its own set of attributes). In other words, instead of having a single ink/paper/brightness/flashing control for each character, each of the 8 lines had it's own attributes. To achieve this, I used the push and pop commands to transfer data from a buffer to the attributes region (as I was under the impression that these were the fastest commands to execute data transfers - this meant using up all the registers and the primed registers with data), I changed the stack pointer to point between the two regions for reading/writing. A particular issue was that the stack pointer grows downward in memory in the Z80 and the scan data is accessed in the opposite direction (hence only having 24 horizontal characters per vertical line before the race condition was lost - also there was the problem of running out of registers). Of course, the interrupt routine only returned control to the program once the 24 character lines were displayed, and so the only processing that could be done was when the bottom part of the border was being sent out. I did find that graphs looked pretty good on it (black background, multiple coloured graphs on the same plot).
Were this interrupt routine to be run at 60Hz, the timings would be all off if the processor speed is not scaled prortionally. I do remember a game, that used a similar technique (or rather it just used timings to modify the border colour) that made it seem as if a countdown was using the entirety of the TV screen, and not just the text area.
... its own attributes. 😉 (it's is the contraction of "it is")