Yesssssss! The first computer I ever used!

That machine had daily use as a home and business computer for 6 or 7 years. The next 2 or 3 years it got flogged in a factory as a label printer driving a sequence of dot matrix printers. Then retirement and storage once PC clones took over. There was no bootup time so the easiest way to stop what you were doing and get ready to load the next task was to power cycle. Flicked on and off all the time. Primarily used for word processing (note scripsit labels on keys) and label printing using custom apps written by family members when it was at work. Had the same plus games plus VisiCalc at home. Also used for writing a lot of random games, apps, and utilities as I learnt to program. Had 1 game with sound. To get the sound you had to connect up the tape player, Set it to "Record" and hit pause which would cause the sound input to come out through the speaker. Even then, it was more squeaks than sounds as they were produced by writing out certain bytes combinations via the tape interface that were known to produce alien like sounds. Squeeks and squawks only.

I still have my Model 1 with 16K (serial #6841). I piggy back soldered a memory chip into the system to access lower case letters (with a toggle switch to disable for some incompatible programs). I taught myself BASIC and then was allowed to teach a 9 week class in my senior year of HS in 1982. This device gave me the jump start in the computing industry and a boost to my confidence at a very crucial time in my life. Thanks for sharing and taking me back to my roots!

Now 42 years or so have slipped by since I worked a one of the largest Radio Shack stores in the US in Framingham, Massachusetts.and we were certainly excited to get these units into the store and they did sell as fast as shipments arrived. As I remember the story, the computer was first going to be sold as a kit that you built by yourself. After meeting with the brass in Fort Worth, it was decided that it would be better to sell it as a complete unit. Two things I do remember differently than you described. First, the unit was shipped to us and sold with the keyboard and the "video" screen and the tape recorder and the power supply with all the cables. And it was all included in one box for the price of $599.00. And second, the first units only came with 4K RAM but later units could be ordered with 8K RAM. As you pointed out, it was a rapidly changing market so updates and changes came rapidly after production started. I have a slight difference in the clock speed. You stated that the speed was 1774 however the joke at Radio Shack was the speed was 1776--remember this was right after the 200th anniversary of the founding of the US. This computer was incredibly slow. Basic did not help. As a test, a friend and I wrote a program to sort 100 peoples names. Several hours later it was still working. But having said all of this, I remember staying up all night playing with the computer that I borrow from the store over the weekend--Stores were closed on Sundays back in those days. I learned a lot and I also sold many units Thanks for the program that you put together It was fun to watch.

Brings back memories! I worked as a service tech between 1978 and 1983 in an independent Radio Shack dealership (actually two) in Slidell, Louisiana before Radio Shack (later Tandy) clamped down and only ran company-owned stores. I remember the owner successfully winning a lawsuit to remain an independent dealer/repair station per his contract. Needless to say, Tandy hated us :) You are right that the expansion cable leads to the Level II ROM. The original ROM chip was pulled out and the expansion board attached with double-sided tape. The colored jumper wires were attached for power, etc per the Tandy-supplied instructions to the techs. Oxidation on those jury-rigged connections caused no end of grief. Little known fact: When we had to replace or upgrade a DIP chip in the field, we were required to socket it to show it's compliance with the latest update. PITA because some were used in moist environments and the tinning on the chips would oxidize (like you see on the Z80). Later, when the FCC cracked down on emissions, we were required to add stick-on shielding packs to any Model I, II or III that came through the shop whether is was part of the repair or not. We had tons of fun (not!) in fixing the circuit board design errors on any early-model machines (usually the II or III models). It seems we were forever getting service bulletins to cut this trace, jumper from here to there and generally create a rats nest of circuit fixes that should have been found in the original circuit boards. All in all, pretty sturdy machines that would get pretty warm over time and sucked power like it was free. I never liked working on the monitors much since I got knocked unconscious once after accidentally running my right forearm across the back of the cathode ray tube doing a repair. My tech buddy said it tossed me about 6 feet back from the tech bench. Don't remember that but DO remember waking up on the floor. I still cringe every time I see an open flyback transformer...

My Dad drove me to the Radio Shack and paid $875 on his credit card for 16K Level II BASIC TRS-80 Model I after I begged him and promised to pay him back. God bless him. My poor father is dead now and I am a professor of computer science at a major state university in the United States. Thank you, Dad!

I still have my Trs 80 model 1 level 2 in a box somewhere. It was my first computer. Bought it in 1980, a big 16k ! Really enjoyed basic programming on it. They had magazines with games you had to type in which I did and always had a mistake when I ran it.. I had to recheck the 100s lines of coding... argh! but it was fun.

Super fun hacker computer for back in the day... you could get books on how to hack it... including a full disassembly of the L2 Basic. I took mine and put 48KRAM, L2 Basic (used 64K EEPROMs in the original sockets, no extender board needed). It's very simple to add lower-case characters, they're in the generator, you only have to add one wire IIRC. My first real tech job happened because I was a Model1 hacker... all their industrial computers were based on it, Z80 stuff. Made things that connected to the parallel interface... EEPROM burner, etc. Still have that thing somewhere in my junk... you haven't lived until you've used cassette assembler (EDTASM).

You know, back in the day, sound on the TRS-80 WAS an AM radio! You turned into the noise the computer makes and some of the games were programmed to cycle the processor just right to make sound effects and music!

I pre ordered mine in early 1977 serial # 004. Wish I kept it, would be worth a fortune today.

OMG, I remember it like it was yesterday. I paid like 3 months worth of rent and bought a Trash 80 back in 1979 when I was only 19 and wasn't sure what I wanted to do with my life. I drove back home like a mad man, with my first computer on board. Got home, and the first thing I did, was what normal people don't do. I opened it up to see what's inside. Was fascinated by it, and how tidy and beautiful it looked inside. Spent about a day and wrote my first program. An analog clock. Jump with joy when it worked at 6:00 am the next day. This shit of a computer, decided my fate. I enrolled in the EE program at North Texas university and it's history from there. From that date on, I bought every computer that ever came out (including the TR-100). That was until I started building my own custom computers with PC clones and I've never bought another off-the-shelf computer. Thanks for the nostalgic recall :)

In the US market, for $599 you had a complete bundle (and large box) with the 4K computer, the modified RCA 12" set, the power supply brick and the cassette recorder. It's so hard to imagine that the joke of a company Radio Shack is now would have had such a product! Ditto for their audio product line, which in the US was quite good actually. I worked there back then, and that was an era when you weren't ashamed to admit it.

I first learned computing on TRS-80s back in the early '80s. That was a great computer.

It was actually possible to get a TRS-80 Model I without the numeric keypad throughout most of its production run -- not just the very early ones -- if you bought the low-end 4K version with Level I BASIC. The 16K Level II version came with the keypad as standard. It was also possible to upgrade the RAM and the BASIC without adding the keypad, so once in a while you'll come across a Model I with 16K and Level II but no keypad.

It only started being refereed to as the "Model I" when they made the Model II. Technically, it was just called TRS-80 Micro Computer System..

Love it, the Tandy catalogue was the thing of dreams when I was a kid, and I'd have loved a TRS-80, but they were too pricey. Of course, the home microcomputer boom solved the price problem thanks to the Z80 processor, and Sir Clive Sinclair, and Acorn Computers using the 6502. Happy days, writing BASIC programs, and waiting 20minutes for a game to load from cassette on my Acorn Electron. My first job was selling computers for Woolworths as a Saturday lad, 32 years later I still work in IT. These machines shaped the modern world, and our lives.

I spent a good portion of my childhood hacking on one of these. A couple of relevant points: The machine ran at 1.77 MHz out of the box, but almost everyone who actually owned one and was at all into electronics ended up doing a fairly simple hack to double the clock speed, so an awful lot of these actually ran at about 3.56 MHz instead. That was actually _much_ faster and more capable than most of the competition at the time, which I think was part of why they were so popular. There was also a very common (I think almost ubiquitous) hack to add an extra RAM chip necessary to do lowercase (the character generator actually included lowercase characters already, though some of the earlier ones looked really ugly (they didn't do descenders properly), so that was often replaced as well). Radio Shack even offered a DIY "lowercase mod kit", if I remember correctly. I'm pretty sure that the monitor was actually sold with the computer as a set, not separately. I've certainly never encountered any TRS-80 model 1 that wasn't bought with both the keyboard and monitor together. It was true that you could technically hook it up to any composite NTSC display (so you could display it on a TV if you really wanted to) but that required hacking up a custom cable that as far as I know Radio Shack never sold. The tape deck may have been sold separately (I don't remember), but it actually worked with any common audiocassette player (it wasn't a special computer accessory or anything), which lots of people already had, and if you didn't they didn't actually cost that much. The expansion interface (which was a box which sat under the monitor) didn't actually contain the disk drives. It just contained a drive _controller,_ which could then be plugged into external disk drives (which sat in their own separate box(es)) via a ribbon cable. (It also contained more RAM, printer and serial ports, and a few other extra bits, as I remember). You could actually connect up up to four external disk drives by daisy-chaining them. The "Trash-80" name was originally coined by Apple fans, I believe, but a lot of folks in the TRS-80 community sorta turned it around on them, adopted it, and made it their own, and it became something of a moniker of pride in some groups. The 64x16 character display was not driven by price (as far as I know). It was because that made the video memory space a nice round 1K in size, which was architecturally convenient for several reasons. It also made the character aspect ratio much closer to printed text, which made text applications nicer. Also, keep in mind that the 64 character display was at a time when other computers really only had 40 characters across, so the TRS-80 was actually much more capable for text applications like word processing than its competitors (which was the other part of why it was so popular, I think). The 64x16 screen was _not a compromise,_ it was actually arguably a much better character arrangement than what most other home computers had at the time this was released. Regarding audio, you could, at the time, actually buy a little external speaker box which you could plug into the cassette port which the computer could use to play sounds. It only offered simple bit-banged (on-off) audio output controlled by writing 0 or 1 to a port, no fancy synthesized audio or anything, but there were actually some programs at the time that still made surprising use of this through PWM techniques, etc. There were lots of games and such that did include full audio effects using this method, and even a "music composition" program that featured multiple voices, and an editable graphical depiction of a musical score sheet, etc. These computers were certainly not "mute" by any stretch of the imagination. It's also not really fair to say it had "no graphics to speak of". There were actually a _lot_ of games, paint programs, etc for the TRS-80 that made use of its pixel-graphics capabilities. Sure, it was only black-and-white, and you could only draw in blocky, non-square pixels, but you could still do a surprising amount with that if you put your mind to it, and many people actually did to good effect. Oh, and it wouldn't actually hurt anything if you plugged the wrong cable into the wrong port, it just wouldn't actually work (obviously). They were at least bright enough to take that into account with the design.

We used Model 3s and 4s when I was in school We had someone demonstrate the coolest thing I ever saw one of these do. Actually that should be heard, not saw. The screen didn't do anything. He placed an AM radio next to the computer and tuned to a free frequency. The program he loaded started playing a digital noise version of Michelle by the Beatles!

Started my engineering career working bench for Tandy in 75 through 82 and designed the serial to para I/O board that was used when they replaced the Cassette with a Shugard 5 1/4" floppy drive...

10:37 - TANDY! Was the best store in the world. Used to love going in there and sniffing the packs of 1/4W carbon resistors. Mmmm, electronics smell!

Oh man! This is the one that started it for so many folks...including me! THANKS DAVE!!

I used to work on these back in the 80's and i still have one that i must restore to life one day . Back in the 80's i made a load of hardware and software for them, i never marketed / sold it though :( . Audio samplers, 512k ram extension , RAM based NEWDOS/80 (no need to load overlays from floppy/HD) plus much more.

Your tear downs are so insightful and packed full of knowledge!! Very interesting stuff!! Please keep up the great work!!??

Incredible image quality as always. Love your stuff.

I've really gotten into retrocomputing over the last year, so I especially enjoyed this teardown. Thanks, Dave!

Great retro teardown! Lots of fun to watch! Nice job.

Dave, that was awesome, and beautifully filmed too (love those macro shots). It was 4 years ago I found your channel when you did a teardown of your old Tandy 1000 (EEVblog #32)... and I just found my old comment on that video! I had no idea back then that this would be my favourite channel on KZfaq. Good on ya Dave.

I love these teardowns. I recently moved and found my first PC stuffed in a crate that I had forgotten about. It was so much fun opening it up and powering it up again. It was HUGE! Six inches tall, 24 inches wide and 18 deep. It had the very first generation Intel 386. And it was the first PC that came with 1 meg of RAM. It operates at 20Mhz and has a 20 meg harddrive. And, it had two 5 1/4" floppy drives! DOS 5.0 The hard drive was corrupt so it would not boot, but I cannot bring myself to get rid of it.

I used to be a software dev at Microsoft, and I personally saw and heard BillG say that the Model 100 had his last _significant_ amounts of new shipping code. He said it during the Q&A section of a company meeting, circa... 1994 or something like that. Not necessarily the _very_ last code he shipped, but the last meaningful amount of new code.

I still have mine. Still works.

Wow the new desk for tear downs is absolutely perfect--looks great!

I made clone of that model I with my friends as a hobby project in beginning of -80's, pcb and everything. It worked when we figured out that due different TTL's it tried to boot to disk unit proms, but when some resistors where added to extension bus it booted without it. I still have it, it is not exactly same because keyboard was different, but 99% same. Keyboard was made from old IBM machine (white and blue keys... :) and monitor was tv with video input :) . We where kind of professionals at that time working with 8080 based boards, so we know what was going on. Very cool project at that time :)

Nice video. I thought you might give a shout out to the Dick Smith Electronics compatible computer that was also sold in Australia. The expansion module didn't have a floppy drive within it. Instead it allowed multiple devices - printer and floppy drives - to be connected. The box was bigger than the computer but most of the space to allow the external power supplies for the computer and the drive to be included within it. The problem in Australia was the 240V supplies were too big to fit. My brother and I grew up playing the various games on one of these, so much so that we wore through to the second layer of plastic of the case just under the keypad. (Our father used VisiCalc and word processing). Sold mine at a flea market for next to nothing. I hope the buyer got value from it. Ours also had a third party patch which allowed hanging characters in the word processor. I still remember going with my dad, back to the computer store opposite Nunawading Station in Melbourne, to get it installed.

ohhhh ... My first computer :))

One of my first computers, handed down from my Dad. We had a hardware hack that put in some extra logic and a toggle switch to toggle capital/lower case letters for use with the Electric Pencil Word processor... And I actually used it up until High School for Word processing.. Also had the Level II basic expansion.

My grandfather gave me a TRS-80 CoCo2 as a kid, I just hooked it up to our TV and bought a cheap tape deck for saving data. Worked great.

I spent many an hour programming in BASIC on my TRS-80. I loved it. Thanks for the memories !

Great to see this computer again. Brings back some great memories. Thanks. The Model One was my first computer. I bought the floppy drive expansion box and the original Radio Shack branded Centronix dot matrix printer. Learned how to program in Basic on the Model One. Upgraded to the Model Three as soon as I could. After the Model Three came the Apple Mac-Plus and I am still a Mac user.

I never had a look into the TRS80. Thank you for this insight, Dave!

The Heath H8, also introduced in 1977. Spent many hours looking at that page in my catalog. Spent many hours looking at the TRS-80 page in the Radio Shack catalog too. The first computer program I ever saw running was written on the spot on a TRS-80 model 1 by the sales clerk. It printed my name in a zig-zag pattern on the screen. Of course, I was hooked, and programming has been my profession.

Nice video! I had one. Bought it with 4K RAM but Radio Shack allowed me to upgrade it to 16 K RAM without warranty issues. Later I added another 2 rows of 16 K RAM piggybacked on top of the original ram with the Chip Select pin driven by an extra decoder. I replaced the character generator with an EPROM and added some memory for lower case. In the end, I could switch it between the normal character set and one with the special APL symbols. And, of course, added better graphics. I got hold of two 5 1/4 inch floppy drives and designed and build the disk interface and a real-time clock and serial port to connect to a home build 75/1200 baud modem to get on the bulletin boards. The PCB edge connector for the expansion interface was absolute rubbish. I soldered a proper gold plated connector onto it. I never had so much fun later on...

The Model 1 was my first computer. A very expensive Xmas gift for a13yo. I had 4 siblings and we were not a well off family. I think my parent saw it as an investment. After I got it I don't think I slept for three days. You couldn't do anything but program it and that is what I did -- and still do today. I added the expansion interface, a printer and two floppy drives over a few years which gave me a whopping 16k of ram. I sold it to a comp sci professor at a local college and then bought my next PC. I considered an Apple 2 but ended up with a DEC Pro 350. Maybe I missed a bet there but knowing more server side stuff has serve me pretty well.

This video was a trip down memory lane for me as this was my first real computer after building a single board MK14. I wrote and sold some programs to run on it and spent many happy hours in the local Tandy shop on Saturday mornings swapping ideas and programs. Unlike mine though the "silver" coating on the front of the keyboard seems not to have worn away. Happy days

Ohhhh!!!! The memories!!!! TRaSh-80!!!! Cut my teeth on these as a spotty teen. Thanks so much Dave.

A 16K Level II BASIC TRS-80 Model 1 was my first computer, back when I was 12. I used the snot out of it. Things I remember: - The keyboard felt good, but had an awful keybounce problem (i.e. repeated letters). There were a *lot* of third-party debounce programs you could get and it was pretty much a requirement to load one every time you started it up. - I remember taking the trim panel off the monitor and seeing the holes where the tuner knobs would have been in its original design as a TV. - I played most of the Scott Adams (different guy from the one who draws Dilbert) Adventure games - lots of fun. - There was a third-party peripheral called the Orchestra-80 which you could hook up to the slot where the expansion interface would connect to and which would allow you to play 4-voice music. - My favorite game was SubLogic's Flight Simulator 1. 3 frames per second at 128x48 resolution, but still, I was flying! - Assembly language programming went like this: 1) Load the assembler (from tape). 2) Load the source code (from tape). 3) Edit the source code. 4) Save the source code (to tape). 5) Assemble the code (to tape). 6) Load the assembled code and run it. 7) If there's a bug, return to step 1).

Love the old tech teardowns Dave!

Hello again, my very first love! I didn't even own one, I used to write my programs on paper and type them into the display model at my local Radio Shack. I learned programming that way, thanks to the salesmen who didn't kick me out even though it was usually a school day and I was probably skipping typing class. Thank you Rat Shack!

I learned to program BASIC on one of these. :-)

you tearing down those machines is perfect material for binging KZfaq, keep up the good work!

Notice the holes in the front of the monitor case for the channel selector knobs? They are covered up by the gigantic label. It really was a retrofitted B/W TV!

We actually owned a Video Genie II with the numeric keypad (TRS-80 clone). Upgraded with 2 floppy drives, 300 baud modem and graphical upgrade. We completely took it apart and mounted it in a desktop case with separate keyboard case. Best computer years I ever had!

Man... Talk about a trip down memory lane. I remember playing on these at Radio Shack. It's the machine that I started to learn to program on.

This was the last computer I owned where I knew the entire schematic almost by heart and understood exactly what every gate did.

I had one - received as a Christmas gift from my dad in 1977. It was great.

You failed to mention that the expansion edge card connector was only tin plated. I had a close friend, R.I.P. Kent, that tried to clean his with WD40 (didn't know better, but didn't really do any harm). He used it with a memory expansion box (which I am trying to visualize in my memory but can't quite. Anyway, I remember Kent getting a gold plate upgrade kit for that connector. It soldered on to both side and a gold plated board (or connector, I don't remember) then stuck out the back I remember soldering it on for him and the reliability of the expansion interface improved 100%. He used that computer for many years actually. I was living in another state at the time of his passing and don't know what his daughters, who I was not close to, did with it (he never threw stuff like that away so I am sure it was there in 1997. Anyway, gee thanks, now I am very meloncholy right now.

We had a TRS-80 Colour Computer 3! So excited for this!!!

A loverly trip down memory lane dave. I remember my friend asking me to drop by his place to check out his new personal computer back in 77, that is where i started programming computers in BASIC and later bought an Energy Control Apple ][ + clone.

I've got one of these, had it since 1980... it's what I cut my teeth on. There's lots of aftermarket info (including the L2ROM disassembly) available... I had a friend burn some 8K EPROMS so I was able to upgrade without the extension board... put my own 64K DRAMS in (jumper one bit to the address buss), add lower case (one jumper wire!)... I had cassette editor-assembler (EDTASM), made my own EPROM burner, etc... even did a light pen program for my uP2 final at comm college. Having one of these put you head and shoulders above the classmates using the little 6502 breadboards. Then I got a job in industrial computing... based on the Trash80! We used Model 3's for lots of things. The insides is very familiar to me!

I had a TRS-80 with extended color basic purchased in the mid 80's for a whopping $50 US. On mine, the heat sink wasn't sufficient to keep it cool during constant use. After a day of use, I fell asleep, and woke up to a melted plastic case and blown power supply circuitry. Still the best machine of its day. Made the Apple look like the PC of a simpleton. My hat is off to RadioShack for producing the first true PC for the masses.

That extra key near the EI connector is a reset button. They used to have a cover which would flip down and protect the connector. Most people discarded these as they got in the way of the reset button. Also, the monitors did come with a grommet. :-)

Very entertaining video, I remember playing with the TRS80 when I was a kid. My first computer was an Atari 800 home computer. The Atari 800 probably was the first really affordable do it all computer. I remember I had a thick book of nothing but basic programs that I typed in by hand and then executed. Those were the days, my iPhone and iPad are far more powerful and entertaining then that was but I remember spending days and days at my Atari 800 computer. Thanks for the video.

My favourite Dave teardown so far

Awesome! My first computer that I got in 1988 was a Commador 64. I was 8. It was bought in a garage sale. But I did learn a lot from it.

Dave, the lighting in this episode is spot on. Good on ya mate.

my first computer as well... mine was the level one with the ROM upgrade board that converted it to a level 2, and added the keypad, after you cut a hole for it!! BTW, the little switch next to the expansion port was a hard reset, that you needed sometime when doing asm programing!

I used a Trash 80 while in the Navy with scriptset as the word processing program to write Nuclear Plant repair procedures.

I had one of these in 1978!! I learned all about BASIC language, and used it a lot and had a lot of fun doing it!! --- John A Bellas I think my unit had the 16 K upgrade and tape drive (CASSETTE) .

I had the Hong Kong rip off of the TRS80 called the Video Genie II and loved it. It even had a build in tape deck with volume control. 16K memory and learned how to program in Assembler. Those were the days. :-)

Back in the 70's and early 80's when I worked on developing solder mask technology, getting the coating to work over tin/lead was a pig, 3 cheers for the transition to SMOBC and HASL technology.

At the beginning, I zoned out, and thought I was watching the antiques roadshow. Dave is just so great at these things :D

Loving the work area!

Need to do a write up on the Model 1... I was one of the folk in Tampa that was on the team that wrote BASIC for the Southwest Technical Products 6800... I forget the name of the exec that called us and offered $10k for basic. The others in the group negotiated the terms...while I did the BCD math package and then the string handlers.. (Was teaching Z80 assembly at that point)... We figured 9 months max to get the basic going. The shack was supposed to have a target hardware package to us by August of the year... Came December, and no sign of hardware.. A flurry of phone calls in January and February resulted in our withdrawl from the contract. There was a hard coded date for finished code that was march of that year, and we were going to have to troubleshoot all the hardware interaction.. the word from Tandy was "Don't worry about the contract." --- They had been known to sue and destroy anyone that was a day late on stuff.. so we got out. First shipment: Lee Chin Wang's tiny basic in the box... When that was a total dud...So they went to Gates to get Microsoft Basic.. In ROM.. (Hard to pirate roms!) --- Gates wanted something around $100k... Tandy's CEO said "How about $10k and $xx per machine? Gates had been burned by MITS... so he finally settled on a figure around $56k... Doing that, knowing that the box with its 6 digit serial number wrapped 3 times.. IN other words - a million in sales roughly. Had they taken $50 per machine, they would have multiplied the take by 10x minimum...

OMG. I remember this well. Here is where I started. TRS-80 rocks.

This machine was the start of a 40 year career for me. I had the 4K Level 1 BASIC version with the cassette tape drive for storage, and I upgraded it to 16K with an $80 kit from Godbout electronics.

I worked for a company in California, Compatible Electronics, and we did FCC testing. It was funny when you mentioned that this would not pass FCC regulations I for once understood what you were saying :) I'll tell you in the early days of the 80's with Windows 3.11 just coming out we did a lot of testing for AST computers out of Irvine California you should do one of their early 80's computers for a teardown and see what a mess they made trying to pass FCC regulations its hilarious the mess they made with copper wire and shielding!

nice. I learned how to type and program basic on those old beasts. Still so weird to think back about saving to cassette

Sending me down memory lane here! Although for me it was the TRS-80 Color version that a friend lent me during the 80s, back when I tinkered with BASIC programming, some of it coming from Compute! magazine....

Thank you Dave, it was fascinating.

The Expansion Interface didn't have room for floppy drives. it was a plastic platform that had room for a single largish PCB and a cubby for a daughter card (extra $$) if you wanted an RS-232 interface. There were cut-outs around the periphery to expose connector edges on that PCB or various things, including a port you could use for external floppy drives. Originally single-sided, 83K floppies. To save money, we used to use a paper punch to cut out a symmetric notch so we could flip them over and write on both sides. :)

I used to program at school with an Apple II Europlus, but since I could not afford one of these at home I used to play around with one of these in the local Tandy store. Probably with the TRS-80 Model III or IV. In 1982 I bought a TRS-80 Color Computer and loved to program on this for many years. It's in my garage somewhere and I want to pull it out someday :-)

Very cool, that monitor was so built to a price point, and dead simple to make. It started life as an RCA as Dave mentioned, To make it into a monitor, tuner and IF section was removed the IF, video/audio demodulator was all on that circuit card standing up in the left of the TV it was then replaced with a direct video drive board and the cable run out the place where the volume control had been and a plate placed over the holes where the tuner had been. Made in Taiwan The higher end RCA TV's of the era like the XL-100 color sets where made in Indianapolis Indiana.

Brought back some memories Dave.

Love these retro computer teardowns. Thank you!

In college they dumped a big pile of junk and in there I found a TRS-80 monitor. The model number is KTR 122S, manufactured in December 1977. It has a gromet in the video lead, and the chassis is different. I don't know why the flyback lead has no insulation cup, there was some corona discharge producing ozone in mine, so I installed one from an old TV. It appears it feeds on a composite signal isolated by an optocoupler.

Sound was achieved through the cassette out connected to a small telephone amp (or whatever amp you wanted). All the games supported sound that way. The button you were pressing by the edge card connector (tucked in back) is the reset key, soft to push, hard if you hold down break while pushing it. Also, the monitor did have a grommet or some sort of strain relieve there, it was missing on that model, but google pictures and you'll clearly see it. I did a lower case mod on mine that involved soldering a ram chip onto another (piggyback), that and a replacement char gen chip, hence the reason it was socketed. I worked at radio shack and I asked the tech about getting it done and said save yourself the money, tossed me a chip, a piece of wire and the char gen and I did it myself. Also, the expansion unit didn't hold drives, it enabled drives, (contained the drive controller hardware), as well as an additional 32k of ram, an rs-232 board for data, a printer port, and a data bus since you use the one on the main cpu to connect to the expansion interface. Interesting thing about all the RF you covered. A guy (from my home town actually) wrote a program that would play music, wirelessly of course, from the computer to a nearby radio. He used machine language loops and figured out what sized loops produced what frequency and had the computer playing music through radios :)

I used one of these in high school in 1979. The "monitor" is actually an RCA b&w TV. I had one at home in the mid 70s.

A very fine looking specimen of a classic computer, if ever I saw one.

In that classic ceramic package, I love it.. They are vintage stuff. :D

Love the video, I was a Tandy bench engineer in Wednesbury UK back in the day, I did all the mods on these units.

TRS-80 Model I, my Father's first computer when he was a littler younger than I.

I learned to program on one of these things. I had an early machine that developed terrible key bounce. You could hit an "A" and get "AAAAAAA" all across the screen. I had the upgrade done just to fix the keyboard bounce. The original language was better that the full version of basic you got with the upgrade. The machine I bought in the USA came with monitor. I went on to buy a floppy drive and a printer. Work I did at work in a day I could come home and complete in an hour over my lunch hour on the trash 80. When my superiors saw this they got me a IBM for the office. So, lots of memories.

I make it from scratch when I was à young man. In the 80'. I have a lot of pleasure with my clone of trs80, with floppy disk 8''. Now, I'm retired and have fun with arduino and raspberry. But I buy it, no make with my solder Iron, and this it's no very fun. René from France.

Great, classic Dave style video

The first computer I ever used. Our 7th grade computer lab in 1978 had about 30 of these PCs. I vaguely recall the storage device on a cassette tape player and the computer seemed very, very slow. Ah, the memories...

I had the original model (have) that I bought when I was a paperboy! Speaking of loud RF coming from it, there was a music program for it that used the effect very well. You had to tune a radio to a certain frequency and set it next to the computer to hear the music! The song that came preloaded in the program was the flight of the bumblebees! Ah, those were the days!

I had a TRS80 copy called a Video Genie. The main drawback was the tape storage which required endless fiddling to get anything like reliability. Unfortunately it wasn't Kansas City standard but an analogue system. Went on to the BBC 'B' which was a vastly improved kettle of fish and incredibly versatile. Hard to think of this being described as 'vintage' :) The first computer I worked on was all discrete germanium transistors, drum data storage and real core store for RAM (or IAS). No keyboard or VDU, just switches, lights, and card reader/punch. Now THAT'S vintage! LOL

Many kids from the 70s remember the Apple II and Commodore PET because of their popularity in schools. Even if the TRS-80 outsold both in actual units, the vast majority of people didn't have any computer at home, School was the first place most of us touched a computer. (in my case it was the Apple II) I was very aware of the TRS-80 as I was a budding nerd whose yearly rite was getting the annual RadioShack catalog. I'd end up with a I and later a III. The one Radio Shack computer that Gen Xers have a fond memory of is the TRS80 Color Computer, An entirely different machine.

good that he noticed the different size screws. The spacers are equally important. Radio Shack repair shop once sent one back to me with all the spacers missing and wrong length screws in some of the holes.

Layout of PCB has certainly come a long way since that was built, can remember using black tape to make traces for a PCB shop in the 80's then shortly getting to use a Computer Vision that took up a whole room. I have respect for the person that layed that board out by hand back in the day.

I'm in my early 50s... in eighth grade my school got one of these. And we did the print name thing. And some programs. I remember seeing it in the RS catalog before that just dreaming about having a computer.... a COMPUTER in my house! I knew computers back then as something in sci fi / adventure shows. The TRS 80 would've ben like having a spaceship in a real way. Thanks for the memories!