The Advantech I.Q. Unlimited with BASIC and a Z80 CPU.
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- Опубліковано 5 лют 2018
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In this episode, I take a look at the Advantech I.Q. unlimited, which was produced by V-Tech (Video Technology Corporation) in 1991.
"The computer your family will never outgrow". I'm glad that my parents decided to buy me a computer before this was on sale. I got a Commodore 64. It had more than 12 games.
oh common man it was so true forget that you out grew the commodore 64 this thing you would never out grow because it was beneath you to begin with so you were to old for it to begin with so you couldn't out grow it cause you already had before it even came out lol
13?
@@Thiesi there are sooooooooo many commodore 64 games. That thing was on the market for like 15 years.
There’s some family out there that never outgrew it and still use it to this day.
I love my IQ Unlimited, but even I think that claim is very unrealistic and quite bogus.
I love this episode because I bought 1 at a goodwill for 99 cents
Lucky!!!
Lucky!!!
Dang, all my Goodwills are out of 8-Bit Guy episodes. They have some iBook Guy ones in there, but they're way overpriced.
Interesting price for a find like that
3:38 That Brother not only plays Tetris, it reads backwards disks judging by the photo!
Came here to say this...
well technically upside down but that's definitely amusing as heck
i was just about to comment on the disk being backwards too lol
I actually have one of these WP-2400s, without Tetris unfortunately, but it supposedly came with other disks as well for similar utilities, and while it is able to use seemingly any 3.5" floppy disk (i used a 1.44mb IBM format disk in it and it initializes it to its own proprietary format), it uses a custom 240k format that can't be read by any other system that i've seen so far.
Wtf i dont see that 😁
I remember telling my parents I wanted a computer after watching Goldeneye back in 95. I wanted to hack and do cool computer stuff like Boris. They bought this from Kmarts going out of business sale for like $40 back in 1995. This was my first computer. Second one was a hand me down 1996 Packard Bell my uncle gave me around 1998.
At least the Packard bell could do more stuff. I had a Packard bell computer in 1995 and it was awesome
Some comments on this machine. The TMP42C50N microcontroller has 512 *bytes* (not kilobytes) of ROM and 32 *nibbles* (half-bytes) of RAM. It seems connected to the keyboard ribbon by a series of resistors, so it probably is a keyboard controller. The 74HC244 seems connected to the printer port, so it most likely works as a printer port interface.
Now we begin with the guesswork. Knowing that VTech had produced the Laser 128, an Apple IIc clone, and that this computer graphics mode is, apparently, pretty similar to the Apple II's DHGR mode (560 by 192, 16 colors generated by color subcarrier artifacts), I'd venture and say that the two unknown chips are an Apple-II-in-a-chip and a ROM chip (containing the firmware and the programs). The LH534NY9 sits next to the microprocessor, typical for a ROM chip, and the 26-5063-01 SMD chip on the backside is similar to chips in the Laser 128/128EX motherboards known to be related to video generation, so I think this is plausible.
If this is true, the use of the 128 KB of semi-static RAM would make sense: the Apple II models with 128 KB of RAM divided it into two banks of 64 KB (main and auxiliary). It wasn't paged memory, you had to switch the entire address space, so you could only access one bank at a time. Because of that, it was usual to use the main bank for the OS, the program, the display RAM and the working memory, and the auxiliary bank as a RAM disk (managed by the OS) or a data storage (this is a simplification, but accurate enough for this discussion). If so, this machine could use the first 64 KB as working memory, and the remaining 64 KB as battery backed storage. This would fit the ad that said "64K of RAM allows students to to use and store programs".
The Advantech I.Q. is amazingly similar to the Tiger Learning Computer (ua-cam.com/video/WZk-utRYrI0/v-deo.html), a prototype of an Apple II compatible educational computer made under license from Apple in 1996 (and cancelled when Jobs returned). Both are supposed to be easy, self-contained computers with no moving parts and a limited software library included. These two characteristics, while limiting to full-fledged computer users, were attractive for parents looking for a simple (and durable) computer for their children. And I'd bet my hat that the Tiger Learning Computer (advertised as having "Apple IIe Technology") was based on Apple's Mega II, basically an Apple-II-in-a-chip created for the Apple IIgs and later used in the Apple IIe Card for the Macintosh LC.
By the way, even if this machine uses an Apple-II-in-a-chip, it doesn't make it an Apple II compatible or clone - because of the Z80 processor. But, in theory, it's entirely possible to stick all the logic of an Apple II (or any 6502-based computer) to a Z80 processor. The advantage? Using a proven hardware design without having to develop it.
Sounds pretty cromulent vs what I was guessing at. I'd figured on 4x 32k blocks and 12k of video memory (which would fit with 6x8-pixel chars and 480x200 total), but if the remaining space readout was rounding up fairly heavily or just dividing by 1000 instead of 1024, then the just-over-13k needed for a 560x192 monochrome display would work too. Guess we need to try and count the dots used in the low rez mode to determine if it's more likely to be 240 or 280 total (or even 320? I don't think the clock is quite fast enough for that...)
That hard bank switching would make loading or saving files a complete pain in the ass, at least if you were using the second 64kb (there are multiple virtual drives, I expect at the very least it's "saving into whatever's left of the first 64k" and "saving into the second 64k" plus use of some additional cartridge or a real disk drive or cassette deck that's been somehow connected). If you can only use one half at a time, you're going to have to shift probably single bytes, maybe two or three at a time max, via the processor registers only (or maybe a few extra if using the keyboard controller RAM too). Though so long as the bank switching delay wasn't super massive you might be able to get a few kb/sec by that method, which would be sufficient for the small files involved.
Bigger issue is - how do we access the ROM? There's 512kb of data in there, and it's all code and graphics needed by the programs. We can't realistically keep banking in 64kb of that with no RAM available, the machine will spend all its time banking back and forth and not even have any spare register space left to do any proper work. Maybe the necessary data for a particular program will be copied across in the same way as loading in a work file, but 12 progs total means each average about 42k. It seems like it would be a very inefficient way of doing things. Better to split the address space into e.g. four 16k chunks... Working memory, VRAM, storage RAM, and ROM... each program actually taking 2 or 3 banks out of the 32 in the chip. Though of course it's not necessarily the case that all of them are used. It could be 12x 32k (=384kb used), or even just 12x 16k (well, actually 13x, as the main startup menu would occupy a space too) with 512k ROMs simply having become cheap enough by 1991 that it didn't save any money to risk speccing it with a 256k before the software was finalised.
A couple of notes on memory banking on the Apple II - which should apply to this machine if it's based on an Apple-II-in-a-chip.
First , when I said that the entire address space was banked, I simplified it a bit. The lower 48 KB of address space banks as one unit, and the upper 16 KB, which contains the ROM, banks as other unit. Both can be banked independently for reads and writes, so you can set one bank for read and the other for write, and copy memory from bank to bank in a thigh loop.
Also, the 16 KB ROM space is banked itself. Starting with the IIc, the Apple II supported 32 KB of ROM divided in two banks, and it is technically possible to use more banks to support larger ROMs. That space can also be switched between RAM and ROM, so you can access the full 64 KB of each RAM bank.
Actually checking on how the Apple II made its video, it ran the pixel clock at exact multiples of the NTSC colourburst; twice for hi-rez / 6 colour mode, ie 7.16mhz, and four times for double-hi / 16 colour mode = 14.32mhz.
That wouldn't gel too well with a processor running at 6mhz... and looking more closely at the text it definitely seems to be 6 pixel wide, not 7. Plus the way it creates its colours is very much different (pairs of greyscales with maybe 5 or 6 levels, rather than 4+ strips of pure monochrome) and the number of them it seems to use is different too (12, not 6 or 16). It's still artefacting, but synching differently with a different set of patterns, maybe closer to how the NES does it (also in the region of 6mhz). Could even be the common 5.37mhz (or 10.74mhz for 80-col) as used with a whole load of TMS VDP-using machines, which just about fit 256 pixels across a TV screen with a small bit of over or underscan, so 40 (or 80) 6-pixel characters would work just fine.
Though I'm wondering now, seeing how the modulator attaches to the "power" PCB - and how the composite output is cosited with the DC input - if the video system might actually be wholly separate, including a CRTC or VDP plus its own 16k or so of memory... very much like the CGA, in fact, and a variety of early 8-bit computers (inc MSX, BBC Micro) and consoles (Intellivision, Sega SG1000), just with the bit patterns for colour mode being interpreted in a way similar to that of the Apple IIgs in its specific hi-rez mode... which can show black and white pixels in full resolution, but any colour appears effectively in low rez, with a limited set of patterns putting black, white, and four primary colours together to make 15 pseudocolours. In this case though it's all greys instead, creating colours entirely through artefacting, and only making maybe 12 overall. At least, that's the most I can count on any one screen in the video.
Yes, it looks like the character cell is 6 pixel wide. It fooled me,
because it uses a character set similar to that of the Apple II, which
used a 7x8 cell with 5x7 active pixels (two empty columns on each cell). This computer seems to use a 6-pixel-wide cell with 5 active pixels.
The palette is also weirdly similar to the Apple II's hi-res palette (black, white, green, orange, magenta and blue) but with two different intensities for each color (full and half intensity). This would also allow for a single gray (half intensity white). The presence of four "primary" colors would point to a 14.32 MHz color clock (four phases over the 3.58 color subcarrier). The pixels look aligned with the color clock, so I'd venture to say it uses a 7.16 MHz pixel clock. This is coherent with the artifacts shown by white text on black background in a color monitor (which are always one of the four colors from the Apple II palette).
There seems to be no apparent limitation on which colors can be on which place, which would point to a true 16 color framebuffer or a NES/MSX-style tile-and-attribute mode. I think the former is more likely, because if it used a tiled mode, why limit the color palette so heavily? Even the NES can display 25 colors from a palette of 54 with just 2 KB of RAM.
Anyway, I can't think of any home computer or video controller with those specs, and it seems weird to develop a completely new chipset for a cheap computer when you can grab an of the shelf part and save the design costs. This is why I thought it used an Apple-II-in-a-chip...
Last, the processor is *rated* for 6 MHz, but it doesn't mean it actually runs at that speed; it's just the part's upper limit. I'd bet it is an integer divisor of the 14.32 MHz master clock bellow 6 MHz, so 4.77 and 3.58 are the most likely speeds. Taking into account that the graphics controller itself runs at either 3.58 or 7.16 MHZ, and doing a 4:3 bus interleave between the graphics controller and the main processor is possible but hard, the processor probably runs at 3.58 MHz. Then, why bother buying a 6 MHz part to run it at a lower speed? Because it probably was the cheaper variant available by the time this machine came to market.
I thought I was the only person who has one of these! FYI: The cartridge slot on the left is for playing Socrates games. (That was the educational video game console VTech had in the late '80s, using very similar hardware to the IQ Unlimited.) VTech also made a later version, called the "IT Unlimited" with a GUI and mouse.
VWestlife I think Retrogamervx showed one of those in a video! :-)
still got it?
I assume it was also unnecessarily software limited as well? 'Unlimited'...
Seriously this company seems to always use the top shelf of words when it comes to describe their products. What happens when they introduce a better model? Unlimited 2, Unlimited Unlimited?, Turbo Unlimited?
Ultra Unlimited?
then the Truly Unlimited?
Then the Truly Ultra Unlimited?
Kind of hitting a wall at this point :P
Born in 83 🙋🏼♀️ After years of trying to remember which computer I had as a small child, today I got some papers from my dad’s house and hold and behold there was the Quick Set-Up Guide for the Vtech IQ Unlimited Computer. And here I am!! Thank you for showing it, great memories!! Hi from Puerto Rico 🇵🇷
RIP JCPenney Christmas Catalog. You are sorely missed.
Thank you for this video. I had this computer as a child and it got me started in programming. I’ve been looking for a video on this computer for ages and you delivered (day after my birthday, no less). Thanks, David!
Michael Lee you deserve it gurl! 😢😄
That is a genuinely awesome story. I love hearing the really random ways some of us got into programming.
I had one of these as a kid and there was an external ram pack that you could store your files on. It had a standard cr2032 battery. I believe there was also an external floppy drive option. At least I recall seeing one offered in the included literature, and I did want one. Oddly it also partly worked with the Socrates game carts. Though you could not really play the games if I recall. I used this as my main computer for about 3-4 years. I still have it, though doubt it works after sitting for 20+ years.
harshbarj pull it out and mess about with it!
Both this and Socrates are z80 based and from the same company, so it makes sense they'd be sort of compatible. But something as simple as changing the memory map between machines could render the software basically unusable.
As long as you didn't leave batteries in it, I'd be quite surprised if it didn't work after a mere 20 years. The Sinclair Spectrum had to reach about 30 before the membranes started to have to be replaced as a simple matter of course.
Kinda want one of these now :)
Interesting. That makes it into a rather more practical and better-value prospect than just the base unit we see here.
I just bought one of these IQ Unlimited computers online and I find it rather fascinating, it arrived today and it works. If you still have the RAM expansion pack and no longer want it, I'm willing to buy it off you if you're willing to part with it.
There are MANY MANY old 8-bit computers which are forgotten, and for good reason. Some are forgotten for bad reason, too.
Which ones in your opinion are forgotten for bad reasons?
@@maybebabyny I liked the TRS-80 model 1. It was limited, but fun to use. I liked the Apple ][+, though that's not forgotten. I haven't heard much about the Amiga series recently.
this looks so familiar. i think this is what we had in the house when i was a kid in the 90s. picked it up and taught myself a little bit of basic right out of the box. the language was so approachable.
i even had an apple IIe with everything including mockingboard, bunch of games and apps, mockingboard card too. speakers, joystick, disk drives. neighbors were having a garage sale. i asked them about it and they just gave it to me. was dope
@@buddyroach Lucky, I've only ever seen an Apple IIe at school
I had one. It was my first "real" computer. I've been waiting for you to review this model and I'm glad you did! The weak basic was an issue for me even then, as I was becoming familiar with Apple II basic, Commodore basic, and Qbasic on other computers at the time. As for it's fate, it was left in a storage shed when I had outgrown it. It likely succumbed to water damage before being thrown out.
I have been looking for that tiger math and spelling explorer computer forever. I had it as a kid and loved it, I just could not remember the name to look it up. Then BAM it's there at 3:28 in the bottom right. Crazy nostalgia overload.
Hey! Cool seeing you over here on this page. Love your videos!
Thanks :) 8-Bit Guy is probably my favorite channel.
Useless Duck Company
I can't find any videos of that tiger computer :(
computer
It says it's a 200 year calendar but it only accepts 2 digits as a year when booting?
Good point.
Krzaku
Technically that would make it an infinite calendar since it can only display two year digits, it would just loop every 100 years.
In this case, for me, February 29th makes the difference, think about (example) the date 29.02.89, the next day will be 1.3.89. Besides, if you think 28.02.89 and the next day is 1.3.89, now you can notice that it is really a 200 year calendar. It is may sound silly as long as I used only one date occurrence and the aforesaid example also applies for a 100 yr calendar but if you find this February pattern n times in certain a century, i assume that next century will show this pattern =/n times.
Calendar isn't necessary the same thing as the real time clock, nor is the real time clock's limitations necessarily the same as the input field of the time prompt when booting
Jose Antonio - Except there's a special case with leap years where if the year is divisible by 100 but not by 400, it's not a leap year. 1900 was not a leap year, even though it is divisible by 4. 2000 was a leap year because it is divisible by 400, but 2100, 2200, and 2300 will not be (not that anyone alive is likely to see the year 2200 or 2300, or anyone old enough to understand this video on the day it was released to see 2100).
Also, your example year was not a leap year, so there was no "29.02.89". '88 was a leap year, so that would have been a better example.
16:20 "Not sure what speed it's clocked"
Time for you to get an oscilloscope, sir!
Frequency counter
You can probably find a crystal somewhere on the board ... if there's nothing other than the NTSC colourburst one, then it's using that, and likely running 3.58, or for later Z80As, 7.16MHz.
If even that can't be uncovered, just try and figure the pixel resolution and how wide a sweep of the screen they cover, and compare that width against a machine of known frequency and resolution. The TV's beam will scan at a fixed screen, so active width is equal to active period; pixels divided by period will give you video clock frequency ... which in a machine like this will almost always be locked either directly to the CPU speed, or in a fairly simple ratio (2:1, 3:2 etc) to it. Which gives you a most likely speed, plus a limited number of alternatives. The CPU markings themselves should also reveal what its maximum speed is, and usually the host machine will be designed to run at or close to that (EG one with a chip marked with an 8MHz maximum speed probably runs faster than whatever the next speed grade down is, likely 5 or 6MHz...), and in concert with the other information should help narrow down the realistic options.
Update: Looking into / refreshing my memory over how the Apple ][ video modes created colour, as this machine sure does seem to use at least a variant of the same method if not completely copying it, you are pretty much locked in to using a 14.318MHz master clock, as that's what creates the pixel clock in double-hi-rez graphics (560x192 1-bit on a mono screen, 16-colour with 140x192 effective rez on a colour screen, possibly you could shoehorn in a 4 or 6 colour 280x192 mode but that doesn't seem common/official) and 80-column text modes on the ][c and ][e, as well as the colour waveforms in original low-rez (40x48, 16 colour) mode, and is subdivided by 2 to make the pixels in original hi-rez graphics (280x192 mono or 140x192 6-colour) and 40-column text. All the other frequencies in the system are also divided out of that master, including the CPU at 1.023MHz ((315M/22)/14).
As the system smacks quite a lot of a ][c reference design (including the under-used 128KB RAM), with the 6502 CPU replaced by a Z80 for some reason, and almost all the original logic squashed into a single LSI chip plus a couple others which weren't convenient to fit into that, plus the floppy controller virtual "card" replaced with the bundled software ROM, I'd be surprised if it does anything different.
The CPU in this case is therefore probably running at 4.77MHz, the same as the original IBM PC, and arrived at by the same method - 14.318MHz divided by 3. If you've got a 6MHz Z80 available, that's the best you can do without adding extra oscillators and clock generator hardware, because /2 is 7.16MHz (too fast) and /4 is 3.58MHz (slow enough that you could have used a regular 4MHz Z80 instead). It's also about the slowest you can run the chip whilst still getting a reasonable speed boost vs the original processor (a 3.5MHz Z80 is arguably on a level with a 1MHz 6502, but a 4MHz has a better fighting chance; 4.77MHz is definitely quicker), in order to compensate somewhat for any suboptimal coding (VTech probably doesn't attract the world's best coders), inefficiencies from simple source porting, any need to swap endian-ness of 16-bit data, etc. It may look like it runs a little sluggish here and there, but without that extra 50%, it'd be noticeably worse (like... a third worse. Of course.)
It might also be something to do with the memory, which looks like it's rated for 100ns? 10MHz? (Same difference?) Either way it may well be running at a good 7.16 if not 14.32MHz, taking advantage of the higher speed rating to allow the video system some extra slots besides the CPU access (in the original Apple, this was taken care of by the memory being good for 2MHz, whilst the CPU ran at 1MHz). Maybe there's even some kind of fancy /1.5 divider, x2 synthesizer, or just a 28.63MHz master clock involved to make a 9.55MHz memory clock possible. It only really needs a fairly minimal amount of extra bandwidth (1-bit video at 14.32MHz means shifting bytes at a mere 1.79MHz; as memory usually needs at least two clocks for a single transfer, that comes out at 3.58... 4.77 + 3.58 = 8.35, so 9.55 leaves a little bit spare).
Alternatively the video accesses could just fit into gaps in the Z80 machine cycle where it doesn't touch the memory bus at all, and the memory is merely overspecced (it was just whatever was cheapest in order to provide at least 64KB, or maybe the full 128 so that working memory and document / image storage could be kept separate and bank-switched, at a minimum of 4.77MHz operating speed), though I'm not convinced that would allow enough bandwidth without some degree of contention and processor waitstating... which may itself be a reason for the higher clocking, so that it has some chance of executing any instructions during the active video portion of a line, even if it's at a reduced rate. (Memory running a 7.16MHz could work though, with a bit of glue logic to interpose between it, the CPU and the video, maybe with a bit of buffering for the former; if the chip only does one access per four clocks, a reasonably common thing for anything other than the 6502 at the time, that would demand an equivalent memory speed of about 2.39MHz; that + 3.58 is clearly less than 7.16)
The final alternative is that everything runs at 7.16MHz and they're simply overclocking the CPU (Z80s were quite resilient against the practice AFAIK), whilst underclocking the memory. With an even sharing of bandwidth between the two, there's just enough for the video to run 80-col 1bpp (with that very Apple ][-looking, thus probably 7-pixel-grid, and 560 total pixels), and the CPU to operate at full speed, without any contention or shortfall. Each gets the equivalent of an uncontested 3.58MHz memory chip, with the Glue logic doing some simple round-robin buffering to guard against both systems making a memory IO request at the same time... a pretty common thing in almost every computer system of the era other than the (non-Jr / Tandy) PC compatibles themselves.
One oddity seems to be that, in colour / 40 column mode as seen on the monochrome display, it isn't actually using super thin on/off stripes, but wider ones in a few shades of grey. This is an entirely valid alternative to the Apple ][ method, produces the same effective colour resolution, and if it's 4-level uses the same amount of memory and bandwith for a given display (and therefore, the frequencies etc are the same), it's just a touch more complicated on the electronics side (have to provide a 2-bit resistor ladder DAC rather than a simple single TTL), and results in a different, and likely more restricted set of colours, with probably only about twelve unique ones in the full palette. This would seem to match what's observed though, as I wasn't able to count more than that many, and the palette is a bit weird even vs the Apple. Plus there are multiple greyscales, which this scheme would allow, but ][c/e DHR didn't.
Similarly it looks like it gives a somewhat wider image - the ][ had a bit of a horizontally compressed image even on a regular TV, a bit like that of an ST or C64, to ensure it fit within the underscan limits on even a curved tube (similarly, the choice of 192 instead of 200 lines), which also gelled nicely with Woz's idea of using the 8th bit of each byte as a colour palette indicator. This machine looks like it might be showing a full 320 (or 640) pixels instead, which again is an entirely valid thing to do within the calculated operating bounds. The Amiga (running a 7.16MHz pixel clock) shows that it's a neat fit for a typical TV, you can make the colour encoding a little more logical and less prone to fringe artefacting (thus easier to program, and much nicer looking) by running 4 x 2-bit subpixels within each 1-byte block (with a resulting effective 2-pixel colour graphic or 4-pixel B/W text resolution, ie 160 colour or 320 B/W on a line) and happily sacrificing the 8th-bit mode switch because you're already getting twice the palette range of the original system anyway, and use a slightly more refined looking - or at least, slightly more loosely spaced, either way is more readable - 8-pixel-grid font. 80-col mode just splits each of those 2-bit subpixels into two 1-bit ones... and would have worked fine on a regular TV if only they'd thought to run a line to the modulator to switch it into B/W mode / turn off the per-line colourburst when it was activated. (Without that signal, a colour set will treat the incoming signal as pure monochrome and not attempt to decipher the hi-rez patterning, ie the text, into lower rez colour smears)
or just look at the crystal...
That port in the back is an expansion port, and yes, the other is a ROM cartridge port, for which there were a total of SIX ROM cartridges available, mainly for expanding the database of the already installed programs, including the BASIC commands.
That expansion port I do believe was intended to serve as a way to connect a disk drive or some other data device, but never got implemented.
I've seen many of those types of chips like the one you first ran into after removing the RF shield, and usually, that is one of those 'all-in-one' things, similar to poxie blobs...lame.
I knew someone years back that had one of these, and everything that it could of come with. It certainly wasn't worth it's weight but...still a neat niche of a collector's item...
I bet. At least there was cartridges for this.
Amy Carter, do you have any further information on these ROM carts? I haven't found any proof of them from my own internet sleuthing.
@@jakenned91another comment says this computer could play Socrates game cartridges
Cool episode! Thanks for sharing. Btw the 74HC244 is indeed an 8 bit buffer instead of a shift register and I believe it is related to the reading of the keyboard matrix pretty much like the speccies did it assuming that the diodes close to him (te HC244) go to z80 upper address lines.
Currently binging Halt & Catch Fire. This channel = the perfect after-show. ✌🏼
I remember the infomercial for that computer. Tom Bosley was the spokesperson for it. In fact, I managed to record about 3-4 minutes of it onto VHS back in the day. It was soo hokey. The computer was being marketed to people who wanted to learn but didn't know anything about computers, and for the kids to do homework on.
A 74HC244 is not a shift register! It is an octal tri-state buffer IC. Commonly used for driving higher loads / greater fanout, or perhaps for reading real-time input values onto the data bus (eg. if it’s output enable was activated by an address decoder).
Looking at the circuit, it appears to have a diode/Capacitor circuit commonly used for debouncing on the backside of the 74HC244. My guess is the 74HC244 is used as a true buffer to read input values from the expansion port and the diode/Capacitor circuit is used as a hardware debounce which ultimately goes to a uC ... IMO
Hi @geekfeather. Taking a closer look, I can see that 'ENABLE A’ (pin 1) input is tied to GND (10), possibly also ENABLE B (but pin 19 trace is obscured by under chip trace). This identifies the 74HC244 is a permanently enabled buffer. Some of the visible input pin traces as well as some output pin traces route directly to the 25pin printer port. The other side of the buffers appear to go back to the micro-controller (must be GPIO pins). On this basis the HC244 appears to be buffering all of the parallel printer port's input & output control lines. The diodes are likely over voltage / spike protection. Cheers.
@@gregclareOne of my pet peeves is when people think the 74HC244 is a shift register instead of an octal tri-state buffer IC.
@@customsongmaker Yes, as I’m old school and grew up when we were designing our own 8-bit microprocessor systems in the 80’s, I immediately recognise 244 octal buffers. We commonly used these for address and control bus buffers, and the associated 245 bidirectional buffer for driving the data bus. Although, I’m not sure why anybody would confuse the 244 with a shift register, especially when data sheets are just a google search away these days.
The intro and outro music somehow make this content 100% better. Not that it's not fun anyway but damn, those sweet 8bitguy trackz.
I had to go back and listen --- I don't think I ever heard an outro for this channel. I really like it. I honestly wish Dave would use that as his intro. Its a lot cooler. The intro he uses now sounds too much like those cringe worthy school films we used to watch in the 80s/90s on wheel to wheel.
Conner Rhoads personally I like the intro music.
Just discovered your channel, it is AMAZING ! so well explained and so full of stuff ! Thanks !!
Man, 1991 I was seven years old playing the shareware of Duke Nukem 1 on a 386 PC.
Had this thing as a child. As a silly child I tried to do things with the ports. Remember those cheap game carts that had the lcd built in? I put one in there somehow and it triggered some "Music Maker" mode but then crashed. I never was able to reproduce, and no idea what it was about (left over ROM data?) Would be interesting to learn more about it.
The Ti 83/84s are still using 6 MHz Z80 CPUs and sold for $120~$150.
At least the Ti-Nspire versions use 350 MHz 32bit ARMs, and also go for $120~$150.
I had to Google that immediately. I knew 8-bit processors were still useful, but you just blew my mind! 🤯
I just love how your videos are educational and fun to watch at the same time! :)
I really did enjoy learning from you. All your videos are fantastic.
3:39 Not only does that Brother model feature Tetris, but it also seems to feature a disk drive where, apparently, the disks go in backwards!!
Me thinks these machines were a cheap effort to scam the average consumers who weren't very tech savvy in those days... which were a great many people. The BASIC is less than bare bones, the LED is one line, the keyboard is rubbish, there's no additional software outside the boring built in programs; for 200 bucks in 1991 you're only ripping yourself off. If you really still wanted a good 8-bit micro by that point, the redesigned C64 for $150 would have been the best choice.
Great video, by the way. :)
I'unno, the hardware basically seems to be an Apple ][c just with a ~5MHz Z80 in place of a 1MHz 6502 (and so operating just slightly faster, realworld). One of those plus a basic software bundle might have cost you about the same at the time, maybe quite a bit more because of the built in floppy (the mechanisms were still fairly costly), without the nominal portable capabilities. A "real" laptop or indeed any other kind of useful portable computer would have been much more expensive and not at all kid friendly, or able to connect to a TV.
The real failing of it is the lack of additional software. Like perhaps VTech made some carts for it, but they evidently weren't very widespread and would have been limited in number, as well as carrying a heavy bias towards edutainment games. Thing could have really done with a floppy add-on, and allowing third party devs to make stuff for it... probably wouldn't have taken much more than recompiling Apple ][ source for the Z80.
I was kinda thinking the same thing myself. A Z80 processor in 1991? Were they insane?
It's a bizarre machine, and it doesn't seem like the manufacturers really thought through what it was they were trying to achieve with this thing.
I think Dave's right, those awful wordprocessors would be the best bet, $200 cheaper than a c=64, ($150+$50(software)+$200(1541)+$200(printer)), vs $400. You got a better display, spellcheck, grammar check and it was a lot more capable for writing than a C=64. Your kid will hate you and will never go into computer science, but they won't be playing games, pirating disks and they'll be able to do their assignments... ugh. That said, some of those wordprocessors had DOS disks or could be used *as* a printer, and I bet that external monochrome monitor is a generic composite one. You might find a junk XT or something to upgrade to... having flashbacks to my horrible childhood.
Great video 8 bit dude. You always make it feel like the warm 80s when I watch your stuff.
Great video as usual, and that is a really interesting piece of entertaining tech. Still looking forward to seeing David messing around with ZX Spectrum, though :D
3:39 - Stay tuned for seventeen Brother WP-2400s coming to a Feb 2018 unboxing video near you.
Wal Ter that was my first thought too, lmao
Shit, i have one and my first thought was to send in mine since i don't have any use for it anymore, since i don't have the tetris disk, unfortunately.
FORZA ROMAAAAA!!!!!
Why did i post that lol I don't even remember
August 2020: No WP-2400
Interesting machine, great video :)
My first computer in the 80's was a version of Vtech Laser 2001, namely the Finnish version, Salora Manager. The Basic screen looks a bit familiar to me.
I wonder if Salora Manager / Vtech Laser 2001 Basic commands for graphics work in your Vtech computer? How about trying this, "Your first computer program" from Salora Manager manual :)
10 GR
20 COLOR=1,3
30 CIRCLE (75, 50), 20
40 CIRCLE (175, 50), 20
50 PLOT 70, 145 TO 75, 150
60 PLOT 180, 145 TO 175, 150
70 FOR X=75 TO 175 STEP 1
80 PLOT X, 150
90 NEXT X
100 CIRCLE (85, 60), 5
110 CIRCLE (165, 60), 5
120 END
If it goes to graphics mode, you should get back to text mode by typing:
TEXT
and pressing enter.
I love how slowly the pictures representing the question categories in Mind Challenge are drawn.
I started following your channel because while I am only 30 my first computer was a C64. I loved that thing. I haven’t touched one since I was about 6. But man all of your videos on 8 bit computers and retro tech make me want to pick up another C64 one day. Keep up the good work!
V-TEC KICKED IN YO!!!
Shingo? What are you doing here?
Sorry if I'm missing something, but who's Shingo?
Vault-Tec Rep I knew somebody would comment this 😂
Vault-Tec Rep (9000rpm INTENSIFIES)
shingo is a character in the anime "initial D" that drives a red 90s hatchback civic
Any day 8 bit guy puts out a video is a good day.
man i just love your intro tune it makes me so happy
I hope to see more restorations from you soon, they're my favorite of your videos!
Great episode! :)
Wishlist: A whole video dedicated to the SID chip in C64.. There isn't any video on it anywhere.
+Marius VanDamme I bet it will be covered in the upcoming Commodore History episode. Surely David won't miss one of the best features the C64 has.
Yes fingers crossed. But I would love to know more about the technical aspects in particular, its insides, the connections, etc. :) Would be worthy of its own episode for sure.
I've been close to doing this video myself since I spend/t a huge amount of time programming the beast. So I think I will. G.
Forgotten piece of computer history for sure...forgotten in various trash bins after the kids got tired of all the 12 programs on it.
I remember wanting something like this when I was a kid and my mom told me that I'd get bored of it, and that I'd be happier with a regular computer.
vtech just did the mfg, advantech is an AWESOME company that makes motherboards and chipsets and accessories for embedded devices. I used to use their 386 3.5-inch single board computers for building medical equipment in the late 90s, awesome company and awesome people
I do not know what happened to myself, but when I began watching David's videos (+ 8-Bit Keys) some days ago, I started being interested in soldering and keyboards while in the past I did not even want to try those! (LOL!!) Great job, David! Thanks for making me interested in more things except computers!
Well, in 1991 they did have gameboys. So there's that.
Fratm Atari lynx too yo
I had a Game Gear in 1991. It was rad, besides the horrible battery life of 5 seconds. I could not imagine bringing a word processor on a car trip. This is still a great video though, I had no idea that VTech made stuff like this.
You can't do BASIC w/ those pieces of crap. :)
I mean, considering that the Game Boy is a) a handheld, b) came out earlier, and c) was a dedicated game machine and not a home computer, chiding it because it can't do basic is a little unfair.
:D I was joking.
The little microcontroller at 16:10 has 512 *bytes* of ROM and 16 *bytes* of RAM, not kilobytes.
also the x244 is a buffer/line driver and not a shift register
Wow 512 bytes, that seems tiny to me.
@ Booze & Metal : I actually had no idea, thanks, seriously those machines had such limited resources yet were pretty decent when it came to capability.
512 bytes is about right for a vintage microcontroller though. I'd be curious to know where the screen memory is though because 16 bytes isn't going to be enough for that.
There are modern MCUs with similar amounts of memory, e.g. there are ATtiny variants with just 1K ROM and 32 bytes of RAM - some simple tasks just don't need more. The screen memory is most likely included in the main 64K - that would partially explain why the word processor shows so little free memory.
Never heard of this computer before, so it was nice to see a rundown of it here. Good work.
Thank you for answering questions I've had about that computer for years, you're my new best friend.
Great episode!
Ktoś z Polski :-)
3:40 is that disk in backwards?
lol yes it totally is
Haha, yes, I paid attention to same :-) Maybe just for advertisement, so people understand it is a disk there.
But made we wonder is there ever been any floppy drives that would accept disk that way around. I mean it should be technically possible, though kinda stupid :-)
It's in a holder slot
Right around the time that I was fully in the thick of personal computers back then, and I never had heard of this one. Nicely done video, very informative.
Another great video. Always enjoy this retro computer stuff.
Wow, my first PC was a Laser 8088 clone from Sears. Never knew it was made by vtech. It was built like a tank in a heavy gauge steel case with a huge (lol) 40mb MFM hard drive.
Love me some zilog computer
Dimitri Andreou i
me too! I'm glad they still manufacture the CPU!
Another geek topic ,number stations, z80 was used on machines that synthesized voice
Dimitri Andreou lol
Never disappointed with your videos, thank you.
So I just learned today that you have to go back approximately 4 years to hear the 8-Bit guy not sound like a smarmy jerk half the time. Good to know, he has cool stuff
This is the best in 11pm!
I wonder if the extra RAM on that 128K RAM chip is used for file-storage? It’d be difficult to store *all* your files *and* program data in only 64K, would it not? Maybe it did some kind of page-swapping thing where the program could access the higher parts of the RAM chip for “permanent” data storage somehow? Although that word-processor program *did* say it only had 24K when you were typing in it... Oh well...
I’m sure some well-intentioned parents and grandparents who knew literally nothing about computers bought a bunch of these for their kids/grandkids back in the day. Bunch of kids who wished they’d gotten C64s. ;-)
Yeah.. I pity the poor kid who got one of these for Christmas instead of a C64.
I am sure that is why there is 128k and the extra circuitry is on there. I suspect that they would not need to bank swap either. I suspect the area is mapped in hardware as a drive, probably handled by one of the mysterious chips on there. 128k chips would still have been considerably more expensive than 64k even then, and the storage ram has to be somewhere.
LMacNeill
I can't imagine the paltry storage capacity would last if the poor kid who got one really liked to draw
It sounds like something I would've gotten too easily if I kept begging my mom for an Amiga and got this instead. That happened to me a few times where I ended up with an Atari 8-bit computer instead of the Amiga 500.
I do hope you find the typewriter with tetris built in!!!
Coming home to see a new 8-Bit Guy video after a long hard day is always awesome.
Wow, I just randomly got suggested this video and I can't believe it. I got one of these as a kid, exactly how you said--grandparents bought it for me from the Sears Wishbook because I wanted a computer. Unfortunately I wanted a Mac, but they really did think it was the same thing. This was great!
Love the 8 bit guy this video came up on my phone and strait away watched it
Matthewdoesmc81 //
Yeah man, one of only two channels I get notifications for
Ram Laska guessing the other is 8-bit keys?
ikr he's so awesome
Matthewdoesmc81 // Did the same lol
Haha! Actually, I do enjoy (and am subscribed to) 8-bit keys, but my (only) other notification channel is +Ringway Manchester.
Cool channel about 2-way (generally amateur) portable radios, and very interactive and nice channel op.
Cheers!
Even the Commodore Plus4 would have been an infinitely better computer for the time and that thing was what, like $100? I think it went for even less in the early 90's!
R33Racer But it's for people in need of IQ!
I agree. The Commodore Plus/4 had a very good version of BASIC, better graphics and sound than this educational toy. Still, I think this IQ computer was geared towards children aged 7 to 13. For learning and for typing a few pages of homework, it was adequate. The Plus/4 was a home personal computer and not as user friendly as the IQ.
This is eerie. I just pulled this exact some computer out of my garage the other day after doing some cleaning! I never used most of the features of this thing (I wasn't that interested in computers until the mid-late 90s), but I remember using the typing tutor program on this thing in the back seat of the car once in a while, and also hooked up to the TV for that missile-command style typing game.
5:52 "It's good for using in the car"
Gameboy: am i a joke to you
8:58 "Not to hard." Gets annihilated, lol.
Apparently, at 3m38s the Brother not only features Tetris but also a FLOPPY DRIVE THAT READS DISKS BACKWARDS !!! WOW !!!
3:38
And the Commodore 64 has come full circle, they are averaging $150US with shipping/etc on Ebay. I know because I just bought one, lol. I grew up on the C64, your channel is the main inspiration for me finally taking the plunge! Thank you for all your hard work David!
Love your videos! Look forward to every video
The first Unix editor was ed, and you worked on one line at a time. Of course this was the early 70's.
You probably got to see more than 20 characters at once, though, I'd expect. Especially if you were using a teletype.
How about using DEBUG to format an MFM hard drive then using EDLIN to write AUTOEXEC.BAT and CONFIG.SYS? If you screwed up you had to start over because EDLIN was an *output only* text file creation program. Once you hit Enter, the line was written to the file with no way to change it. I did several PC setups like that back in the day.
Is there a port of DOOM for it?
VTech shoveled/shovels out a dozen of propietary computer platforms that have zero support of any kind.
...So there is still a lot of virgin grounds to break for Doom :D
Me too! In the shitter at work!!!
It'd take quite a bit of reverse engineering just to get to a point of running arbitrary code on it... but it should still be possible.
No, but there is a heavily modded port for Wolfenstein 3D, called Wolfenstein 1D. IDK how it would work for something with an LCD display, though.
I want doom on this. I need another piece of obsolete hardware to run doom.
OMG 😲This is how I got started with spreadsheets, databases, and programming! What a flashback!
I used to have this as a kid. This plus my old Atari 2600 is what got me interested in electronics and computers in the first place.
That BASIC is pretty... basic :)
It's not very "All purpose" though.
+o c e a n m a n - Seriously, this Tide Pods meme has to die, now.
T H E I R O N Y
Depends on what tide it is, because you know, low tide is more basic...
..Just because I decided that it is...
Eat vegetables!
Seemingly much harder than tide!
9:03 Hades? Naked? Bach? OMG...
Yeah, hours of fun for kids, right? :-D
Curious piece of hardware! Thanks for sharing with us.
I owned a Laser 3000 computer back in the mid 80s and was unaware until today that it was a VTech product- all I cared about back then was what it cloned rather than who made it- an affordable Apple computer. According to what I read, it preceded the Laser 128 which makes sense- it was an Apple ][+ clone (minus lo-res mode, which had me a bit miffed back then) which apparently came out in 1983 whereas the Laser 128 was in line with the //c and came to the US in 1986 (according to Wikipedia). It would be interesting to see this bit of history included in the upcoming Laser 128/XT documentary if it hasn't been finished yet.
Where did you find the vintage Sears catalog? Is there a website where they can be browsed?
I’m not certain, but bitsavers does have some catalogs
The TMP42C50N has 512 bytes of ROM and 32 4-bit words of RAM, according to the datasheet I saw.
yes, 16k
There is 16 bytes of RAM and 512 bytes of ROM.
oh
Oh my god.....
Yeah, but if it's only doing a very simple job within the machine, it might not need any more than that. I could imagine such a controller, with a different ROM mask, being perfectly capable of looking after the requirements of a basic but competent electronically controlled washing machine, for example. So if what it does in the VTech is equal to or less than that kind of task...
As for it being a video controller, I kinda doubt it. It's not the sort of thing microcontrollers tend to get used for, and of course the memory isn't anywhere near large enough; even the half-K ROM isn't enough to even hold a proper character set. It might be working as a basic GLUE type chip, running the LCD panel, keeping the backup memory alive whilst the main machine is turned off (a simple 4-bit uC will use _far_ less current than a Z80), or maybe most likely it's the keyboard controller. You see Motorola and Intel equivalents in the ST, IBM PC etc.
The video display is probably looked after either by the mystery VTech proprietary QFP surfacemount chip on the top side of the board (maybe some form of ULA), and/or just the Z80 itself. The computer doesn't do anything that requires any kind of serious processing power, and if we look at the example of e.g. the ZX81, which can produce a 256-pixel monochrome display at 3.5Mhz with about a quarter of its processing speed left, a 6Mhz one should be able to provide 80-column monochrome and 40-column in 4 greyscales (which are then manipulated into artefact colour), with 6-pixel wide characters. With a more Spectrum-like ULA being able to give at least 480 pixels at 3-bit greyscale/artefact colour quite easily so long as it was running at twice the speed (as per the Sinclairs; the CPU-built images taking advantage of its 2-phase clock instead...), and fairly sprightly performance for this kind of application. The Amstrad PCW after all ran just fine with a 4MHz chip and a 720x256 monochrome display.
Oh, and the actual ROM is that otherwise mysterious VTech DIP on the underside, which does indeed hold a full 512k. Essentially all the programs it runs would fit quite comfortably onto a single 3.5" DSDD. Googled for the codes printed on it and found someone else had already managed to ID it as a Sharp-manufactured mask ROM...
(FWIW I figure all of that 128k is used, probably with 32k permanently locked in as working memory - which it doesn't need much of if the software is largely running from ROM - and VRAM (12k is more than enough for 480x200 1bpp or 240x200 2bpp), and a second 32k out of the other three quarters swapped in as file storage. After all, the things you write have to live *somewhere,* and the file handling routine appears to split the available pseudo-SRAM into three virtual "drives". And the word processor says you have 20kb free when you start a new file, which is just _far_ too convenient... 32 minus 12... though I might have thought it would save straight into the "drive" bank rather than the working memory, in which case perhaps there was already 12kb of files in that bank... ;-)
We were a few years behind in Ireland, I remember getting a C64 for ~£200 in 1992 with just the datasette and a T2 cartridge and it was pretty cutting edge at the time
The extra ram was used as a ram disk.
The Vtech labeled dip next to the cpu is system rom.
The edge connector on the back was intended for use with planned floppy drive that was never made available.
The cartridge port on the side was compatible with the VTech Socrates game ROMs
4-bit micro controller appears to be handling the keyboard and may be involved in the memory management;
The custom chip on the other side is probably th video chip.
Perhaps they were buying known defective ram modules where only half of it worked and thus saved money, that is something that companies do
0:37 first apple watch
Thank u for doing this video because this was my first computer
I could binge watch your videos all day.
I'm pretty sure that screenshot on the C64C was NOT an actual application that could run on it; but the question remains: what IS that CAD application? and what DID it run on?
I've used 2D and indeed 3D CAD software on an ST, including in its low-rez mode, so 320x200 with limited colours need not be a barrier to the concept... just might have a slow redraw rate and be limited in how complex a design you could construct. There's all kinds of surprising software available for the 8-bits when you start looking beyond the games. Also I wonder if the 64C could still have 80-column and other such expansions added to it which might have made it more of a practical prospect?
9:04 There's two words you'll NEVER see in today's kids' computers.
yeah... But hey, I guess you need to learn to spell those words too!
I didn't mind seeing them!
Besides, it's not like you're spelling the actual word of those 'parts'.
Elijah Vincent
Let me guess, is it the words Bach and Naked?
Ronaldo Rodriguez You got the second word. The first word is "Hades".
Holy crap.. I distinctly remember those 1991 catalogues. Ahh.. memories..
I had a blue one of those with the handle like in the catalog page you showed. It was basically the same trivia questions and everything, just minus the TV connection.
That Brother / Tetris word processor in the Sears catalogue had one particularly weird thing in the photo: the 3.5" floppy disk in the drive was.. backwards? Was that actually a thing, or technical incompetence?
Interference22 most likely technical incompetence by their marketing department.
Those bastards, now they've gotten me wishing I had a backwards floppy drive....
On a side note, the ad got me curious, are the 240KB disks proprietary, or are they just 720KB DSDD formatted in a funky Brother format?
I have the same question, I thought 720KB was the minimum on 3.5" floppy, the Amiga started with that as double-density.
@@marcusdamberger Amiga formatted disks were 880k, not 720k.
Think that mystery chip might be a driver for the LCD?
Nope, the "blob" is the LCD driver.
Your organized cords on the wall are inspiring
I got this in 1991 for Christmas when I was 12. You couldn’t tell me I didn’t have the best gift ever. I had a 13” tv I used with it and an Epson 9 pin dot matrix printer from Radio Shack. I ended up using this thing all through HS and college until about 1998 when I bought a Compaq computer. LOL.
Is it me or are many of the inserted floppy disks in those catalogs inserted backwards? They have the clip to outside instead of the inside. I guess some photography genius thought it looked better that way...
Probably a photography and graphics design team that had up to that point still used Polaroids for proofs and lighting tables to look at slides and did all their compositing on a camera stand of some sort. Never having ever touched a computer, and even when Photoshop came on the scene probably refused to move to it for another ten years. That's probably who took the pictures and setup the "word processor" in this catalog shot..
It wouldn't surprise me. I once saw a photo of graphing calculators in a catalog, pictured with an equation screen on which someone had typed a bunch of meaningless gibberish that resembled nothing anyone actually using the calculator for its intended purpose would enter.
I saw that immidiately, too. It was painful.
I only can think that they wanted you to see that disks go in there and not .. slices of very white cheese or something.
The laser 200 and 300 were also very popular in Australia distributed by Dick Smith as VZ200 and VZ300 respectively. I cut my coding teeth on the 200 at age 7, it took years to undo the damage of the location of the space bar ;) from there C64, and then IBM XT the rest is history.
8-bit guy and 8-bit keys are my two favorite UA-cam channels
According to someone called Andrew68K the chios in question are:
- Zilog Z80 CPU (Z84C0006PEC)
- ROM containing 12 built-in programs (VTech LH534HY9)
- (custom?) A/V controller (VTech 27-5063-01 1111F0249)
- I/O controller (TMP 42C50N)
- Printer buffer (PC 74HC244P)
- 128KB SRAM (Toshiba TC518128APL-10)
A disk drive was planned to connect to the expansion port, but never realised. Instead a memory cartridge was supposed to be plugged in there.
1991!? They had 386 computers by then! They sold an early 80's basic machine for $200 in 1991, what a ripoff!
mrjakeisnumber1 They had 486 (1989) computers by then and the Pentium (1993) just two years after this 1991 8-bit computer. I bought my first 386DX in 1986 with a 150MB ESDI hard drive (there is an interface type few have heard of!) and 2MB RAM ($1000/MB at the time), that is how far behind the times this VTECH computer was on its release day!
A 386 in 1991 especially a portable one would have been $4000.
IQ unlimited? It must watch Rick and Morty
Love to see old computer/toy packet, nice vid
This looks an awful lot like a VTech Pre-Computer 1000 with a video module glued to the top of it; all the way down to the keyboard design, legends, and design of the internal display's contrast switch. The PC1000 was also a z80.