Where did you start with Micro controllers?

In 1966 the company I worked( aerospace ) designed a package with a Rolm computer.The Rolm was a militarized Data General. I worked in the Calibration Lab and was sent to a school to learn to maintain the beasts. They had 4K of core memory and you load a bootstrap loader by hand and then loaded a tape with the system from the tape reader on a teletype. In class they would start the load and give a lecture while the teletype clunked on and on.

Jim

Thread revival! I guess I never answered the original question...
I started out on Mainframes, DEC-10s, DEC-20s, and big iron IBM (summer job during college.) I lusted after various microcomputers, starting with the Altair 8080 and SWTP 6800, with more significant interest in Cosmic Elf 1802 and 8085. Later the PIC came out and was even more interesting, plus AVRs and etc. But it was really difficult to get very motivated to actually do much with them when I had entire ARPANet-connected mainframes to play with...

Eventually the DEC mainframes were dying and I moved (professionally) to high-end microcontrollers like 68000, x86, MIPS, and PPC, where the hardware/micro background was useful for low level infrastructure and driver work. I still seem to enjoy infrastructure development more than actual projects...

n 1966 the company I worked( aerospace ) designed a package with a Rolm computer.The Rolm was a militarized Data General

Rolm was founded after DG, and DG only started up in about 1968. Or so I thought.

I started out with the Z80 and in 1978. First machine was a TRS-80 Mod 1 Level 2 BASIC with 4K RAM. Did an upgrade to 16K for $40. Played around with a number of CPM machines and more recently with a couple of microcontrollers. Arduino is by far, the easiest to get started with and has a good IDE that works better than many you have to pay for.

Printers - Seems like DEC had a highspeed Dot Matrix that had like 4 print heads. All tied together on the same carriage so they moved together. That would be like 33 collumns for each printhead.

Tore apart one of those old drum printers. That bronze print drum weighed like 5 pounds. Had small driver boards, 1 for each printhead. Paper would FLY through those machines.

Tore apart one of those old drum printers. That bronze print drum weighed like 5 pounds. Had small driver boards, 1 for each printhead. Paper would FLY through those machines.

Yep, the top of the line drum printers would spit out 1200 lines a min or faster of paper movement. This often created a static electricity problem with the paper moving through the printer so fast that special grounding brushes were needed to bleed off the charge on the paper. Also aliment of 132 print hammers so that the printed characters were perfectly flat across the line was a very laborious and time consuming maintenance task, I hated having to perform that check and adjustment. The testing involved firing all 132 hammers at the same time and using a scope to measure the counter EMF pulse from each hammer relative to the first hammer and mechanically adjusting each hammer to match the reference hammer. The lights would dim each time all the hammers fired at the same time and the noise level was deafening.

Lefty

now that's a printer!

Yep, you went through a box of paper every few minutes. The trick with doing large reports was not losing a page or two as you changed boxes.

I remember too that you sometimes printed carbon copies, the paper actually had the carbon-paper sandwiched between two layers, to you could get two identical copies in the one run. Then there was a gadget that separated the layers and the carbon paper.

My first job in aerospace was designing a SRAM card to use in place of UVEPROM so the software guys could download code and not have to keep burning/erasing UVEPROM boards. Whopping 320K bytes. 2nd task was updating that to 768Kbytes and adding 32K of EEPROM.
Also ran on a 20 address-bit ROLM bus with 2910 bit slice processor, 110nS cycle times to receive the address and the read/write control, decode if it was for the card, and have data back out on the bus. Had 4 or 5 memory cards in the system, plus other cards that responded on the same bus. 21st address bit added later on.
Eventually all the memory was pulled back into a single processor card with an intel processor.

Z80 and 6802/9, early 80s.

designing a SRAM card to use in place of UVEPROM so the software guys could download code and not have to keep burning/erasing UVEPROM boards.

I designed a Z8-based EPROM emulator but only 32k IIRC, large enough for most embedded work, had it on the market for some time.


Rob

My first start with electronics was with a 150-in-ONE project kit at aged 11. I have vivid memories of wiring up a crystal radio and tuning into my first AM station (in Jakarta) which was playing the (then) newly released smash hit number one: Eye of the Tiger by Survivor...

As I grew up in Australia, I went through the entire catalog of Dick Smith Electronics (DSE) Funway into Electronics kits, building almost all of them that I could afford with my allowance and any money I earned delivering junk mail and working at a shoe shop on Saturday mornings.

In my mid teens I watched in awe as my best friend built a Z80 based Ferguson Big Board computer. I, however, got hooked on the software side of things and spent my late teens writing serial (mostly FOSSIL based) communications utilities to interface bespoke POS systems to Gilbarco petrol pumps; linking NEC PBX systems to Qantel hotel billing systems for CDR processing. I also wrote a tennis school database and a hotel functions event management database while studying at University and working as a night porter/auditor trainee in a hotel. Fun times!

Between 18 and 20 as I studied computer systems engineering, a wonderful course that covered everything from basic programming to operating systems to electronic peripheral design - in one class, I build a wire-wrap ISA bus AD/DA card for an 8086 based PC and wrote a DOS TSR sound driver in assembly language; and a Telix clone in Pascal - those were the days! In my 20s I helped my wife with her CompSci studies, in particular with MicMac assignments.

I then spent 20 years working in the Internet and Telecommunications industry as an R&D engineer, designing and building networks and associated peripherals where I designed a system using Z80 based Rabbit (now owned by Digi) microcontrollers for out of band monitoring of remotely deployed microwave systems. I am now a consulting engineer specialising in next gen IP telephony living and working in Europe.

My most recent return to micro controllers has been with an Arduino Uno and Arduino Fio which I am using to build my vision impaired nephew a talking temperature guage with scrolling LED text display. The experience has been fantastic! Mixing the best parts of writing code, soldering small circuits and wiring up different gadgets to talk to each other - heaven!

Cheers

Leigh

I remember those Big Boards, what monsters.

I just found the eZ80 (Zilog eZ80 - Wikipedia), what a great-looking chip. I'm reading the data sheet now wondering what I could use one for.

I grew up in Australia

And now you're in the UK, one can only imagine the terrible circumstances that brought that about :slight_smile:


Rob

G'day Rob,

Graynomad:
I remember those Big Boards, what monsters.

Indeed - I don't ever recall my mate ever doing much with it other than zap a few eeproms with the on board programmer (for what, I have no idea!) :slight_smile:

I just found the eZ80 (Zilog eZ80 - Wikipedia), what a great-looking chip. I'm reading the data sheet now wondering what I could use one for.

I remember enjoying the Z80 - Zilog need to find a way to get them out to the mass market / enthusiasts like they did through education in the 70s and 80s if they hope to stand a chance against the current generation of AVRs.

I grew up in Australia

And now you're in the UK, one can only imagine the terrible circumstances that brought that about :slight_smile:

It's a long story mate :slight_smile: Belfast is an interesting spot, too right.

Cheers

Leigh

I remember enjoying the Z80

Some of the Renesas processors are very z80-like. Or perhaps 8080-like.
This includes the RL78/G13 that was recently the target of a contest with free dev boards available.
Actually, it was a bit depressing to discover; I sort of expect most chips available today to have either reached a certain degree of HLL-compatible elegance (like the AVR or MSP430 or ARM), or to have remained stubbornly "quirky" (like the 8-bit PICs.) I wasn't expecting an architecture to look mostly ... old.

Yeah it's nice to reminisce and that eZ80 does look good at a glance, but I don't think there's much point going back to an old-style architecture when you can buy an ARM for $1.50.


Rob

or to have remained stubbornly "quirky" (like the 8-bit PICs.)

I've taken to viewing programming PIC 16-series devices (particularly in assembler) as a form of masochism or aversion therapy.

to have remained stubbornly "quirky" (like the 8-bit PICs.)

If you code in a high level language like C, the core itself is mostly transparent.

1979 ......SYM-1 with 2k ram (and you think 32K is'nt enough ? You have'nt lived in the fast lane mate)
Sadly, 2k was'nt enough either, 4k was pushing the proverbial uphill, just. So I frankensteined an S-100 16k memory board to the SYM memory interface.
All this with my parents bugging me on why I was wasting my lowly wages on rubbish !

SYM1...lol

Maybe was 1982, maybe a bit earlier, but was the same beast, I had access to one when I babysat for a programmer.. And then again in 1983 at a weeklong technology camp at the university of Wisconsin... where we also had access to the university Xerox Sigma Six.

Machine language baby! (lord it was so awful doing just about anything.. I remember a dice rolling program that took me weeks of poring the SYM manuals.. do I get points for the fact that I succeeded, self taught, a year before my first computer class?)

Hey, I still got the boards.
I also bought a second SYM-1 some years later to try out sbc to sbc comms. You're right about learning programming before taking traditional classes. I aced my digital electronics labs at the Airforce training college some years later, and that was on a MicroProfessor.