Built my first computer 40 years ago
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Hah! Bunch of whippersnappers! When I was vewy vewy young, I built one of these: http://www.oldcomputermuseum.com/heathkit_ec1.html[^] Standard output was to an oscilloscope. :omg: :wtf:
I was a keen used of Heathkit (as was my father!) - Had the small scope, the valve voltmeter and the DX100 AM transmitter, but I never knew about the EC1. I'd love to have one to play with now... First computer I built was the Z80 based Nascom 1 kit - about 1976 or so as I recall. Programmed it to play Lunar Lander and Star Trek, which I'd first encountered running on an Elliot 903 / ASR33 Teletype at Leeds Uni in 1973/4!
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Hah! Bunch of whippersnappers! When I was vewy vewy young, I built one of these: http://www.oldcomputermuseum.com/heathkit_ec1.html[^] Standard output was to an oscilloscope. :omg: :wtf:
I remember the EC-1. Always wanted one...
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
Matthew Dennis wrote:
using the Motorola MC6800 8 bit processor
Had me with 6800. Tear-eyed with 6809. Stack down the best 8-bit microprocessors of all time :cool: -- RP
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
About 1980 I built a UK-101 kit computer. Bare-board kit with (most) chips supplied. At the time I lived 5 doors from the embryonic "Watford Electronics" who operated out of the front room of a terraced house, but were able to supply the individual chips I needed. I built the thing in a single night, but by the end I was so tired that for some bizarre reason I soldered the 6502 socket onto the WRONG side of the board. Not being a whizz with a soldering iron, there was no way that baby was coming out again. So I did the obvious... :omg: and bent each pin of the 6502 up though 180 degrees, and inserted the chip the "wrong way up" into the socket. Turned the power on and... woohoo! It actually worked. * Got pretty fed up with the 4Kb memory limit (8 1k x 4bit chips), so examined the circuit diagram carefully. Then soldered on another 8 chips ON TOP of the existing chips, all pins save the main addressing pin. Ran an external wire from that to the address decoder and bingo! 8Kb on-board memory (though rather warm memory). The screen was a paltry 64 chars wide by 16 chars deep. So I did the same trick with the video memory (now 2kb instead of 1kb), addressed the extra 1K through via an external wire again, and cut a PCB track and patched in a second to double the rate at which the VDU was refreshed and - voila! 32 rows of on-screen text, each character now square and using 8 lines of TV instead of rectangular and using 16 lines. Of course the thing was a bit slow, running at 1Mhz, so again a bit of snipping and soldering, and - via a switch dangling in mid-air - I could double the clock rate to 2Mhz. Brill! Next I got a bit fed up with the limited character set; snip, snip, solder, switch; now I could toggle between the full 256 character white-on black, OR I could have 128 characters white-on-black PLUS the same 128 characters black-on-white (inverse video). Smashing! Of course storage was still via a serial link to a cassette recorder, running at 300Baud, making saving programs pretty time consuming. Snip, solder, switch, switch - now I had a hardware switchable baud rate of 300, 600, or 1200. 600 baud was pretty reliable, at 1200 baud you had to clean the tape head every day and use decent quality tapes, but it worked. Then my friends at Watford Electronics had an AY-3-8910 sound chip in the window. So I bought an add-on board (plain drilled PCB, all the wiring external) and knocked up a 3-voice soundboard, addressed directly via the upper regions of the address space. I built a second one, on a differen
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
Back in 1979 I bought a MOTOROLA MEK D1 devkit with MC6800 CPU, 128 bytes of RAM, MIKBUG in 512 bytes ROM as the OS, an ACIA serial port. Had a video controller to fire an 11 in. green monitor. I had a Radio Shack keyboard with no ENTER key. I also had a cassette deck as mass storage which worked at 1200 bauds. I wrote my programs directly in object code. Loved the MC6809 and the MC68K. Had a lot of fun back then. Have lots more fun today. Andy Day
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
Here in Malaysia they used to sell Apple 2+ kits in 1982 - pirate motherboard and all the chips and you put it together yourself. The ROMs were already programmed. I built one and used it for a few years with no problems. My first computer was before that - a Mini-SCAMP. 16 address switches, 8 data switches, 8 leds and a couple of push-buttons - thrilling stuff!
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I played Adventure on PDP circa 1978 but do not remember which version. Never could cross the bridge.
Crossing the bridge: You have to pay the dwarf: Give him the golden eggs (they will return to their original place if you utter the formula FEE FIE FOE FOO) and you can pass. When you go back, you bring the bear with you, that will scare him off.. (Why do I still remember such things? I last played Adventure in 1983, on a CDC Cyber mainframe)...
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Crossing the bridge: You have to pay the dwarf: Give him the golden eggs (they will return to their original place if you utter the formula FEE FIE FOE FOO) and you can pass. When you go back, you bring the bear with you, that will scare him off.. (Why do I still remember such things? I last played Adventure in 1983, on a CDC Cyber mainframe)...
I believe our copy of Adventure was broke as I did that but it would lock after you started to cross the bridge, unless you forgot to leave the bear in which case it colapsed. I to can remember Adventure from long ago, but cannot remember things I should today.
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
I was born with a built-in "digital" computer, which to this day, is still affective for counting, adding and subtracting numbers up to ten, and multiplying by nine. I guess technically this is the oldest computer my parents built.
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
I also built my first computer back in the '70s, though I admit I didn't finish it. I'm a programmer who eventually got tired of programming something that I had no idea what was inside. I based my computer on a PDP8 bus that I had gotten from work, and used the 74181 bit slice ALU chip with the intent to build a 16-bit PDP-11 knockoff. I taped up a set of double-sided boards and etched them at home. No plated-through holes though - just wires soldered in to connect the two sides. I finally got stuck when I got to the proms that I needed to implement the microprogram. They and the equipment to burn them were too expensive. I built a great living-room ready box to put it all in too. The populated boards that I did finish sat in a card box for years until I could bring myself to throw them out (wife helped on that).
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
Heh, memories. I built my first computer back in 1978. It was a Z80 based S100 bus system. Except for the video card I wirewrapped all the other boards. I had a whole 8k of RAM woohoo! No programming language, only a primitive monitor program (named Zapple). I use to know most of the z80 instruction set by the numbers, no Z80 assembler program for me :).
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
In the early 70's I played around with magnetic core memory for a while but didn't get anywhere, but then Newbear brought out their 77-68 board: a 6800 with 256 bytes of memory. IO was two rows of toggle switches and 8 LEDs. I added 1. a speaker so that it could squeak tunes 2. a cassette tape drive to make program IO easier 3. more memory (eventually reached 4k - why would anyone need more?) 4. a type 4b teletype 5. a video board with a vhf output for an old TV 6. an old keyboard rescued from an electronic calculator 7. eventually, a 5.25" floppy disk drive (software for that was a challenge. But then Amstrad started selling their machines that were much less than I had spent on mine. Still got most of that gear in the loft.
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Memories! Built my first IMSAI 8080 with model 15 teletype and paper tape storage in 76. Saw one in California during a motorcycle trip from Anchorage AK and back that summer... Then added a 10 MB 15 inch platter hard drive a year later I picked up at auction for $75.00 and 2 months of wire-wrapping the interface and writing the driver for CM/M
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I designed and built an 8080-based computer on a single board with wire-wrap connections. It had a 6-digit 7-segment LED display and a hex keypad, 1k of ROM and 256 bytes of static RAM. I/O was an 8-bit programmable I/O chip. I wrote some real programs directly in machine code on the keypad (there was no other way to get code into it). I think that was all in 1976.
Phil
The opinions expressed in this post are not necessarily those of the author, especially if you find them impolite, inaccurate or inflammatory.
Yeah, 1976 I bought a kit for the Imsai 8080A with two 5 1/4 floppy drives from Horizon, which came with HDOS. Soldered everything up myself, including 7-8Kbyte memory cards for a whopping 56Kbytes, ADM3A monitor... It was a challenge back then on home computers, no programming languages, except HBASIC from Horizon which wasn't much more than Dec EduBasic on the original Dec 10's. Wrote my own Assembler, Editor and Fortran compiler for it. I can't even begin to imagine how much 8080/8088 assembler code I wrote over the next 10 years... I started programming in 1969 with a ASR 33 teletype connected to a computer center in Seattle and Fortran using IBM keypunch machines using punch cards at the University of Washington on their mainframe.
Lyle
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
Wrote commercial software on an Olivetti A5 in 1977. The A5 was a giant posting machine resembling a hyperthyroid selectric typewriter. It had some horrible 4-bit processor. The thing took these paper cards with a mag-stripe that held 256 bytes of data each. We built a floppy controller for it in 1979. Turns out the A5's printer was light duty, because how hard could you push it if you had to constantly feed it cards. With a floppy, it could run flat out 24/7. The lifespan of an A5 connected to our floppy controller was about 9 months, but it had a 12-month warranty. Ouch. Wrote commercial software on a MITS Altair 680 6800 (note only two zeros) box with 16k RAM in 1979 (to replace the A5 because they wouldn't honor the warranty if connected to one of our floppy controllers). I can't remember what we stored code on. We were building a floppy interface, so it wasn't floppy. But the assembler/editor was on mylar-coated paper tape. We had an optical paper tape reader, so we could load the assembler as fast as we could pull tape through the reader (by hand). This resulted in a big untidy pile of paper tape on the floor which had to be picked up and respooled each time. The 6800 had a 16-bit index register, and programming errors had a bad habit of overwriting all memory locations, so reloads happened several times a day. Built an OSI 6502-based system around 1980. 1MHz processor, 16k RAM (that's K as in thousand)! Overclocked it to 2Mhz, which also doubled the bit-rate of the Kansas City standard cassette tape reader/writer. Men were men in those days I tell 'ya.
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
My home-built computer was an Apple ][ done in wire-wrap, in 1980 during my first year in university, starting from the schematics of the Apple ][ Red Manual with minor modifications to use EPROMs instead of ROMs (different pinouts and different enable logic). The keyboard was taken from a completely different device and modified to act as an ASCII keyboard with compatible pinout. The Apple ][ BIOS was printed in an appendix of the Apple manual so I programmed a 2716 EPROM (2kB) by hand using a Sinclair ZX80 kit with an EPROM programmer extension board (also wire-wrapped). Incredibly it worked and I still have this Apple ][ in some place. After that big work, I hated wire-wrap: too many loose connections to check over and over.
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Just realized that I build my first computer 40 38 years ago. A Southwest Technical Products SS50 bus system. Can't even remember which processor was in it. It was a SWTP 6800 using the Motorola MC6800 8 bit processor. I later designed and build a MC6809 CPU, with 1M memory and CRT controller, card for a University project course. Anyone else remember their stone-age computing accomplishments? Thanks for the links to the information that corrected my memory. "There are 3 things that go with age. The first is memory and I can't remember the other 2". My Mom.
My first computer was a Commodore Kim-1, which was a 6502 (1MHz!) Single Board Computer (SBC). I added an S-100 expansion board to it with an 8K static (!) memory card. I ran tiny basic on it, which you loaded using a cassette tape drive. I was still in high school, so that was either '73 or '74. I only had to solder the S-100 expansion and RAM cards, as the Kim-1 came assembled. I used a Memorex printer/terminal as the console until I got an Intercolor 8001 CRT (look it up, it was awesome for its time. 19" color terminal with an 8085 for a brain). I then built from scratch a complete S-100 Z80 (4MHz - no we were cooking!) with two 64MB dynamic RAM cards (bank switching anyone?). It sat in a Godbout (I may have spelled that wrong) rack mount case (I had a 5ft high rack) with an IMSAI front panel (watch the original Wargames movie to see one) and a Tarbell floppy controller with dual 8in Qume floppy drives (the fastest ever made). I later replaced the CPU with a Seattle Computer Products 8086 (8MHz - warp speed!), still using the 128MB of RAM from before and the IMSAI front panel. I had to write my own BIOS and drivers for the floppy disks (8in and 5.25") and hard drives (SASI - precursor to SCSI). I had four, count them 4, 15MB 5.25in hard disks on that system. That was back when you got a 5MB drive on a PC XT. That system was hot! All running DOS-86, which Microsoft bought and renamed to PC-DOS. That system was running almost a year before the IBM PC came out. Mike
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From which machine did the ancient data originate? They're both ancient. ;P I still own a PDP-11/23 (minus disk drives, they weighed 67 pounds per drive. RL02)
"It's true that hard work never killed anyone. But I figure, why take the chance." - Ronald Reagan That's what machines are for. Got a problem? Sleep on it.
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I beg to differ with you on the AS/400. It runs Java, has hooks for C#, C++, VB, and runs circles around Windows server farms. Just sayin' :-D
OK egg on face. I never expected it to stick around, albeit in a different guise. But.. I made an assumption that the CPU was a big factor in its longevity. Except that the instruction set is high-level (almost virtual), so making it fairly bullet-proof from technology changes. My bad. :-D
"It's true that hard work never killed anyone. But I figure, why take the chance." - Ronald Reagan That's what machines are for. Got a problem? Sleep on it.