17 replies to this topic

[Vorticon]

Back in the late 70's, Radio Shack put out a cool educational product called Microcomputer Trainer based on the TMS1000 processor. I bought one when I was in high school (it was very cheap), but never got too far with it. I rediscovered it yesterday and I must say it's quite under appreciated as a machine language learning tool.
It has 2K of ROM and 128 nibbles of RAM (it's a specially modified TMS1000 chip), a built in machine language monitor, a HEX keyboard, a row of LED's indicating current address, an 8-segment LED for number/letter output, and a speaker. There are 16 fundamental commands and 16 callable subroutines like a timer or a tone.
The manual is exceptionally well written and is really a full tutorial on machine language. The whole thing is laid out on a cardboard plane, and you make the connections using wires just like the old electronics learning kits. It is therefore fairly straightforward to interface the inputs and outputs of the processor, and some have used it for lab work!
You can definitely program useful things with it including games thanks to the callable routines in ROM. 128 nibbles can really go a long way believe it or not That said, the learning curve can be a little steep for someone with absolutely no assembly experience, but then this IS the target demographic, so it's absolutely doable and I guarantee that you will learn quite a bit about microprocessor programming fundamentals, enough to give you the needed base to tackle more complex systems.
I definitely plan on seeing how far I can push this little gem!
The trainer frequently shows up on Ebay very inexpensively, and the manual is available as a PDF online. A great geeky gift for someone interested in programming

Here's some info on it: http://www.old-compu...asp?c=1053&st=1

Edited by Vorticon, Thu Nov 10, 2011 9:15 PM.

[matthew180]

oh oh, me me !! I want one! :-)

[Tursi]

I had one of these too, it was awesome!

[Willsy]

I got one of these. Awesome little thing

[Vorticon]

Willsy, on Sat Jun 18, 2011 3:26 AM, said:

I got one of these. Awesome little thing

Nice! Except that at 255 Pounds, it's a tad on the expensive side While on the topic of trainers, I also dug up a BASYS/1 computer kit I had bought in 2000 from its original designer Lee Hart based on the Cosmac 1802 processor, which is the same that powered the ELF computer. The kit was designed in 1981, and when coupled with an RS232 terminal, will be a fully functional computer with 2K RAM and 8K ROM with Tiny Basic. I have hesitated to build it just yet because I need to beef up my digital electronics knowledge so I can take full advantage of it. Its parts can also be used to build an ELF as described in Popular Electronics. BTW,there is a modern incarnation of the ELF also being sold by Lee Hart called the Membership Card (don't ask...) for $89 which fits inside an Altoids can. I tried to contact Lee to see if he has any kits left, but so far no answer...

Edit: He still has kits and I got one. http://www.retrotech...ip/memship.html

Edited by Vorticon, Sat Jun 18, 2011 4:19 PM.

[Vorticon]

matthew180, on Fri Jun 17, 2011 10:43 AM, said:

oh oh, me me !! I want one! :-)

Well Matt, it's your lucky day.
I was browsing Ebay for classic computer kits and came across this item: eBay Auction -- Item Number: 190592146479 , the Gakken GMC-4 4 bit computer trainer from a Japanese company. It really looked very interesting, so I downloaded the PDF English manual, and it all looked really familiar... Then it hit me: this computer is a complete rip-off of the Science Faire Microcomputer Trainer I mentioned above featuring the TMS1000 CPU! It has the same op codes, callable subroutines, memory addresses and architecture, and even the programming examples are straight out of the Science Faire manual... I don't recognize the chip which seems to be an SMD square about maybe 1/3" per side, and there is no mention anywhere about the manufacturer or the specs.
Who knows, maybe this company has a licensing agreement with TI to clone the TMS1000, but then maybe not. At $32.80 plus another $22.80 shipping to the US, it's not exactly a bargain for what you get in terms of capabilities, especially when you can get an ELF or a KIM replica in kit form for under a $100... Nonetheless, it is interesting, and definitely less bulky than the Science Faire trainer, ideal for a long plane or train ride
So if you still want one, here you go!

Edited by Vorticon, Thu Nov 10, 2011 9:18 PM.

[Mirage]

I have a complete in box Science Fair one. I messed with it for a little bit, was pretty cool, maybe I'll have time to get into it again one day. Was lucky enough to pick mine up for $5 at a garage sale.

[matthew180]

Heh. I think I'm getting my "build your own computer" fix via HDL these days. :-) It is not so much having a 4-bit CPU trainer, but more the idea of having an old TI-trainer. There has to be the nostalgia and authenticity to it, otherwise it is not quite the same.

[Vorticon]

matthew180, on Fri Nov 11, 2011 7:58 AM, said:

Heh. I think I'm getting my "build your own computer" fix via HDL these days. :-) It is not so much having a 4-bit CPU trainer, but more the idea of having an old TI-trainer. There has to be the nostalgia and authenticity to it, otherwise it is not quite the same.

I'm definitely with you there.

[Vorticon]

Mirage, on Fri Nov 11, 2011 5:46 AM, said:

I have a complete in box Science Fair one. I messed with it for a little bit, was pretty cool, maybe I'll have time to get into it again one day. Was lucky enough to pick mine up for $5 at a garage sale.

I'd say that's a good price I always get a kick out of pushing these little machines to their limit, and there are some cool things being done with them on YouTube. With that trainer, all the connections are very easily accessible, so interfacing should be easy enough. The only problem is that you have to type in your program all over again after you shut off the machine... Maybe I should design a cassette interface for it he he...

[JonnyBritish]

Gakken makes a number of these magazine / kits - http://www.makershed...p?Search=gakken

[jens-eike]

My favourite card is like a hybrid TI-99 and TI-59: the TM-990/189 http://www.vintageco...i/TI-TM990-189/

[Vorticon]

jens-eike, on Fri Nov 11, 2011 2:54 PM, said:

My favourite card is like a hybrid TI-99 and TI-59: the TM-990/189 http://www.vintageco...i/TI-TM990-189/

Nice. I did not know this existed...

[kl99]

regarding the hybrid: gerhard w. from our austrian ti group brought one of these boards to our ti meeting:
http://ti99blog.webs...otoid=124346176
as you can see, tom seems to love it

[Vorticon]

kl99, on Sat Nov 12, 2011 4:58 AM, said:

regarding the hybrid: gerhard w. from our austrian ti group brought one of these boards to our ti meeting:
http://ti99blog.webs...otoid=124346176
as you can see, tom seems to love it

Now that's love! The scary part is that I can relate!!!

[scouter3d]

Yes, i really love this Board, so i finally got one from ebay!!!!!

You can see my board here: http://www.8bit-home...tm_990_189.html

Greetings TOM:-)

[RXB]

Wow I remember those. My first one (1976) was the ASR K43 Teletype computer I added 128 bits to by adding ferrited beads soldering 6 inch wire loops hanging from the board.

http://www.columbia....y/teletype.html

Sorry can not find a pic of the K43 only the 33 but was fully metal case and bolted to the floor. Ran on 3 inch paper tape thin cardboard like a player piano.

I tried to find a PUNN TI member here in Portland who had a full on 990 mini frame computer including the 10 inch disk drives, I think he passed away.

[Vorticon]

scouter3d, on Tue Nov 29, 2011 5:39 AM, said:

Yes, i really love this Board, so i finally got one from ebay!!!!!

You can see my board here: http://www.8bit-home...tm_990_189.html

Greetings TOM:-)

Lucky!!! I would kill to get my hands on one in such good shape and with the PS+manual! I'm very jealous...