Author Topic: Adventures in old 80s computers.  (Read 27065 times)

Offline S. Heslop

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Re: Adventures in old 80s computers.
« Reply #25 on: August 03, 2014, 06:21:12 PM »
Thinking about it some more, I could make a portion of the top flat. And the fact that I can't put stuff on top of it might actually be beneficial.

Another thing I was thinking of was copying this and maybe sticking some reference sheets to the inside of the lid, but I can see myself having to take off all the accumulated junk from the top every time I want to open it.

Offline AdeV

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Re: Adventures in old 80s computers.
« Reply #26 on: August 03, 2014, 07:33:59 PM »
Why not go with a drop-front breadbin?



It's got a handy flat top, and if you sellotape (ahem, affix in a professional manner) the keyboard to the fold-up front, you've got plenty of space inside the bin for the actual gubbins :)
Cheers!
Ade.
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Offline S. Heslop

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Re: Adventures in old 80s computers.
« Reply #27 on: August 03, 2014, 09:11:08 PM »
Why not go with a drop-front breadbin?

Never thought about making the keyboard flip out. I'd only considered making the monitor flip up like a laptop. Although to be honest I want to have a go at making one of those bureau style shutters for the sake of it.

But i'll keep it in mind for if I find out the shutter idea won't leave me enough room for the power adapters (I still need to measure them up).

Offline vtsteam

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Re: Adventures in old 80s computers.
« Reply #28 on: August 03, 2014, 10:35:43 PM »
Leave a small space to put some actual bread or crackers in it, too, for late night snacking!
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline DMIOM

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Re: Adventures in old 80s computers.
« Reply #29 on: August 04, 2014, 03:06:15 AM »
Leave a small space to put some actual bread or crackers in it, too, for late night snacking!

to feed the mouse ?    :palm:

Offline vtsteam

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Re: Adventures in old 80s computers.
« Reply #30 on: August 04, 2014, 08:00:50 AM »
no,no, bread boxes keep the mice out....

I was eating Ritz crackers when I wrote that other last night.....
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline S. Heslop

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Re: Adventures in old 80s computers.
« Reply #31 on: August 04, 2014, 04:00:51 PM »
I'll have to use breadboard somewhere in this project. Christ...


I was up all night last night reading about assembly programming. People who can program in assembly are often very proud of themselves, and act like they're gods gift to computer science. But from what I've read (and to be fair I'd only read the beginnings) it seems amazingly straight forwards. It's probably hell to write a program of any serious length in it, but for coding things like C64 demos it seems fairly intuitive. Especially compared to the more ethereal stuff in high level languages like polymorphism.

Reading about it has made me kind of want to skip the whole project and just head straight to covering my desk with all the junk to try out making some simple classic effects. Although it's probably better to leave that till i've got a better setup.

I remembered I had this in the box of my uncle's old stuff too.





It's mostly devoted to C64 BASIC but has a nice rundown of the assembly op codes and the memory map in the back.

Offline PekkaNF

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Re: Adventures in old 80s computers.
« Reply #32 on: August 05, 2014, 02:12:45 AM »
I remembered I had this in the box of my uncle's old stuff too.


It's mostly devoted to C64 BASIC but has a nice rundown of the assembly op codes and the memory map in the back.

That was my book t learn programming (and english!)! I probably tested every page and wrote every code it had.

Pekka

Offline DavidA

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Re: Adventures in old 80s computers.
« Reply #33 on: August 05, 2014, 03:31:19 AM »
S Heslop,

...But from what I've read (and to be fair I'd only read the beginnings) it seems amazingly straight forwards.

Hmmm,  it's not quite as easy as that. Assembler is very unforgiving of your errors.

You do need to read a but further.

But it is very interesting.  and lightning fast once you have it de-bugged.

Dave.


Offline Bluechip

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Re: Adventures in old 80s computers.
« Reply #34 on: August 05, 2014, 05:55:37 AM »

Hmmm,  it's not quite as easy as that. Assembler is very unforgiving of your errors.

Dave.

Oh boy ! have to agree with that.   :thumbup:

Remarkable just how many times you can check errant code without seeing what eventually turns out to be so blindingly obvious you begin to doubt your sanity ...  :bang:  :bang:

Dave [ another ] Ex BBC 'B' & Nascom owner

 
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Offline DavidA

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Re: Adventures in old 80s computers.
« Reply #35 on: August 05, 2014, 10:32:57 AM »
Dave,

And don't you just love the way that erroneous assembler programs can rampage through your system like Atilla the Hun on one of his bad days.
There is NO room for error.

Dave

Assembler86 on PC 386 and Z80 Assembler on the TRS-80.

Offline awemawson

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Re: Adventures in old 80s computers.
« Reply #36 on: August 05, 2014, 10:39:56 AM »
Once you manage to get a protected mode kernel running as supervisor, you can then run your assembler under it's supervision at a lower interrupt priority, saving your copy of the register set on exit. All that Pushing and Popping on the stack ! Then when you think it's all stable the dreaded 'stack overflow' error rears it's ugly head  :ddb:
Andrew Mawson
East Sussex

Offline S. Heslop

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Re: Adventures in old 80s computers.
« Reply #37 on: August 05, 2014, 12:02:10 PM »
That's more or less what I mean by "it's probably hell to write a program of any serious length", it seems the difficulty would be keeping track of stuff as it gets bigger.

Offline vtsteam

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Re: Adventures in old 80s computers.
« Reply #38 on: August 05, 2014, 05:51:53 PM »
Z-80 had the signifigant bites in the opposite order, too. I used to actually recognize op codes.

It was easier to just write most code in FORTH for me and include assembly subroutines (well "words" in FORTH) in it. FORTH had a built in assembler, so definitions for a word could be either FORTH words or assembly language. It didn't care.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline AdeV

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Re: Adventures in old 80s computers.
« Reply #39 on: August 06, 2014, 10:20:24 AM »
I spent ages (literally) typing in an Assembler program written in Sinclair SuperBASIC. The listing was printed over 4 or 5 months in QL World magazine.

Being young and naive at the time, I hadn't realised that Assembler was not the same as Compiler.... I thought it would take my BASIC programs and turn them into super-fast machine code.... oops.

IIRC The program was nicknamed QSLUG in recognition of its slowness...
Cheers!
Ade.
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Offline DavidA

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Re: Adventures in old 80s computers.
« Reply #40 on: August 06, 2014, 12:55:30 PM »
I would be interested to know which computer members first used. And which one they did their first programming on.

My first experience with computers was in 1980 when someone left an (I think) Olivetti machine with me and invited me to 'have a play' with it.

But it was a TRS-80 Model 1 that I learned to program on. Ik of ram, tape for storing my master pieces and only two string functions. A$ and B$.

And, naturally, upper case only.

This lead,  years later when I was at Huddersfield Poly', to me getting a reputation for writing very 'user hostile' programs.

Dave.

Offline awemawson

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Re: Adventures in old 80s computers.
« Reply #41 on: August 06, 2014, 01:35:11 PM »
My first programming experience was weekly sessions in 1968 sitting in front of a Teletype which was on line to a time sharing bureaux. I was writing short routines in Fortran processing measured values for the spectral response of military infra red detectors. It was a slow, long winded business all at 110 baud.

My first owned computer was one I designed and made in 1973 using the Texas 74181 'bit slice' ALU chip set, and was micro-programmed using a diode matrix to form the actual instructions from sequences of logical operations. I think I had 1k of actual RAM. All wire wrapped on home etched boards! Amazingly it worked.

My first non home brew was in about 1975 - an S100 bus machine using initially an 8080 CPU board, and later a Z80 one from 'Tinker Toys' and it was this one that I used to get to grips with assembler coding.

All this well before 'PC's' arrived on the scene.
Andrew Mawson
East Sussex

Offline Bluechip

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Re: Adventures in old 80s computers.
« Reply #42 on: August 06, 2014, 01:41:01 PM »
BBC B+ with a 5" Floppy  [ disk that is ....  :lol: ], at least I did until it got run over. Also had a Nascom 'B' [ I think ] but never got into that thing really. Eventually gave it to a bloke I used to work with at IBM - he was collecting ancient pre-PC stuff. Commodore, Dragons etc. etc.

Then did nowt really until about 1997-ish when PE started faffing with the 16F84 and TK2 .

Dave

I have a few modest talents. Knowing what I'm doing isn't one of them.

Offline DavidA

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Re: Adventures in old 80s computers.
« Reply #43 on: August 06, 2014, 03:12:18 PM »
How did you manage to run over your computer ?

Dave.

Offline S. Heslop

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Re: Adventures in old 80s computers.
« Reply #44 on: August 06, 2014, 03:34:34 PM »
Being born at the start of the 90s, Windows 95 was in full force by the time I got old enough to really use computers.

I said it before but it must've been great to live in a time when computing magazines were actually about computers. By the time I was looking at PC magazines they were more aimed towards people with little knowledge about computers, and never got more technical than installing antivirus software.

I guess the 'real computing' stuff all migrated to the internet, and I didn't get an internet connection till 2005. My parents got caught up in the news hysteria about it and really believed the internet was nothing but chatrooms and pedophiles.

Offline philf

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Re: Adventures in old 80s computers.
« Reply #45 on: August 06, 2014, 04:03:31 PM »
My first programming was at Manchester Poly using Fortran. We had to hand punch cards and leave them with a technician to be run and then collect the results next day. The only alternative then was my trusty Thornton P221 Comprehensive Log Log Slide Rule.

In my early days at work I had adventures with an HP 9825 and a pen plotter. I was intent on building bike frames and wrote a program to plot out patterns which when wrapped around a tube would provide a template to cut to so that two tubes would meet perfectly. I also mass produced my Christmas cards on the HP plotter one year.

My next venture into Basic was with a Commodore PET in my lunchtimes.

My first home computer was a second hand ZX81 which didn't work properly - random characters kept popping up on screen - the guy I bought it off was reluctant to give me a refund saying it had always done that - never thinking that there had been a fault.

I went upmarket then with an Acorn ATOM which had 2K RAM. I bought some surplus boards (where have all the shops gone that used to sell such stuff?) and desoldered the memory chips to expand the ATOM to all of 12K.

I only had the ATOM for a couple of weeks when I was offered a BBC model B. BBC Basic probably still is the best. I designed and built a flat bed pen plotter to use with the BEEB which could even be used to list out programs. The program was all in BASIC and worked remarkably fast considering the speed of the processor. (1MHz). Someone at work bought a Watford DDFS interface which was soon cloned and this gave me access to the luxury of 3.5" Floppies rather than the tedious cassette. Another lunchtime project was making sideways RAM boards into which you could load ROM images from the floppy drive. The program to run the sideways RAM was a mixture of Basic and machine code.

Jumping forward to the 21st century and BBC Basic is very much alive and well and is available to run on Windows (up to and including 8.1) and Linux. There is a free version of BBC Basic for Windows (limited to 16K programs) or for £29.99 you can use up to 256Mb and compile your programs into executables. This is on my list of to-dos as I wrote dozens of programmes to do all sorts of engineering calculations. See http://www.bbcbasic.co.uk/bbcwin/bbcwin.html

I still have 2 BBC Model Bs and a BBC B+ with 64K memory. I suspect none of them would switch on without replacing a few capacitors having been unused for so many years. I do miss the virtually instant start-up and occasionally hanker after playing Repton.

I'm sure that having limited memory forced people into writing efficient code. Many years ago a colleague and I developed a document management system which used VBA (Visual Basic for Applications) to interface Autocad with Excel. A bizarre feature was that you could write a few hundred lines of program and then find a function which could reduce the job to say 10 lines. You would imagine that the file containing the VBA would then be smaller as a result of losing 90 lines. Not so - our friends at Microsoft for some unknown reason never actually deleted anything you wrote even though you thought you'd got rid of it! Thus your more efficient programme was in fact bigger than the less efficient one. You couldn't access the deleted stuff in History so why keep it? The only way round this was to export the modules one by one in to a new project. It made me wonder if all Microsoft software was the same.

Phil.


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Offline Bluechip

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Re: Adventures in old 80s computers.
« Reply #46 on: August 06, 2014, 05:30:39 PM »
How did you manage to run over your computer ?

Dave.

Alas, 'tis a sorry tale ... The village where I lived had a 'Beeb' computer club on Thursday evenings at the local primary school. So, resplendent in our flares and kipper ties we assembled with our kit to boast of our prowess and swap code etc.
I was just about to open the tailgate to load the Beeb etc. into the car and set off when a joiner/shop-fitter mate arrived in his van with a load of really nice strip-wood for use on my model boats. In order to get this stuff into the garage I needed to move the car, so reversed it up the drive ( instead of using the front door, in which case I would have noticed I'd left the Beeb behind the car, I used the side door  ) ....  :palm:

I have to tell you that polystyrene sarcophagus it comes in is no protection against the awful stomp of a Volvo 245 GLT  :bang:  :bang:

So, I was left with a 5" Floppy drive and a Cub monitor with nobody to talk to ....  :Doh:

Really snazzy straight dense grained timber though ...  :drool:

Dave








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Offline vtsteam

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Re: Adventures in old 80s computers.
« Reply #47 on: August 06, 2014, 07:13:20 PM »
Like PhilF my first experience with computers was with FORTRAN and punch cards handed to the university tech, and then waiting days for the result. I didn't do much of that, but it was required for one of my courses. I hated it!

When I got hooked was the late seventies when my calculator stopped working and I went to Radio Shack to buy a new one. They had (besides the Model 1 TRS-80, which I didn't even notice at the time) something called the Pocket Computer -- about the size of a wide calculator. It was programmable in a limited form of BASIC. I bought it and spent days working out routines for my design work at the time. It was great! No more waiting and punch cards!

Well it wasn't two months before I outgrew that and wanted more horsepower. The TRS-80 was too much money for me. But about that time Tandy came out with the Color computer with 4K of ram, used the TV as a monitor, and any cassette deck for storage, and I could afford that. In another couple months I had piggybacked 16K ram chips onto the 4K chips pulling in another address line, etc. Later I got an old IBM Selectric terminal, ripped the boards out of it, used an ASCII to EBCDIC conversion table in reserved memory and had myself a letter quality printer. That soon became old hat, so I built an LNW-80 with my own eprom programmer, etc, etc.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline AdeV

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Re: Adventures in old 80s computers.
« Reply #48 on: August 08, 2014, 09:33:22 PM »
Being born in the early 1970s, I missed the so-called "golden era" of computers that some of the old fogies here will rattle on about from their comfy chairs.... punch cards, paper tape, etc. Golden era my ar*e  :lol:

As any fule noes, the real Golden Era started in the late 1970s with the introduction of the TRS-80, Sharp MZ-80K and Commodore PET computers; and went "mainstream", here in the UK at least, with the BBC B, Sinclair ZX-80/81 and Spectrum, the various Amstrads, the Vic-20 & C64.

My first ever contact with a computer was when a BBC B - complete with colour monitor and disk drives - "visited" our school (at the time, Cheshire primary schools had to time-share the only BBC it owned, I think it stayed for 1 or 2 weeks at a time). I was completely hooked, although I barely touched another computer until our Sinclair QL turned up sometime in 1984 (actually, it must have just tuned 30 years old sometime in the last couple of weeks).
Cheers!
Ade.
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Offline Bluechip

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Re: Adventures in old 80s computers.
« Reply #49 on: August 09, 2014, 04:59:17 AM »

Being born in the early 1970s, I missed the so-called "golden era" of computers that some of the old fogies here will rattle on about from their comfy chairs.... punch cards, paper tape, etc. Golden era my ar*e  :lol:


Don't forget the Noodle Picker  :lol:  :lol:

Dave
I have a few modest talents. Knowing what I'm doing isn't one of them.