# Old computer geeks



## black85vette (Nov 10, 2009)

zeeprogrammer  said:
			
		

> This was back in the day of IMSAI machines and S-100 boards. We built our own.



Zee, you take me way back in the time machine. Wonder how many folks even remember the IMSAI and S-100 bus? I still have an S100 card in my archives. Several years ago I was going thru some old files and found an original sheet listing all the IMSAI frames and board options along with a price list for them. 

For those who don't know. Back then computing was really hands on stuff. You built your own system from parts and made a "computer" with nothing but toggle switches on the front and LED lights for the address, memory and other "outputs". No keyboard, no video monitor, no disc drives and anything you wanted to interface to it meant you had to design and build your own I/O board and write the drivers. We take a bunch of memory for granted now. Back then 4k of static RAM was a big deal and took up one entire memory board. Pretty crude.

The new geeks built with the 8080 or Z80 processors. Older geeks still had 8008 processors in their machines. But the ultra geeks had ripped 4004 processors out of calculators and were building with them.

Thanks for the nostalgia Zee! Sometimes with my FIFO memory I am surprised I still remember any of this. :big:


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## rake60 (Nov 10, 2009)

I don't go back quite that far.
My earliest memories are of writing programs in BASIC.
Then I'd get "syntax error line 5". Fix that and get,
"syntax error line 12". Fix that and get, "syntax error line 23".

I can't say I miss those days.

Rick


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## itowbig (Nov 10, 2009)

i wish i had just a quarter of what u guys know. id be a smart man if i had that.


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## zeeprogrammer (Nov 10, 2009)

black85vette  said:
			
		

> Sometimes with my FIFO memory I am surprised I still remember any of this. :big:



Lucky you! My wetware has gone to LIFO. :big:

Yeah...the IMSAI was fun...toggling in the bootstrap program...

Rick...a fun language was PL/1 and/or PL/C...take it to the computer room...get back about 400 pages of errors...all because you missed a semi-colon.

itowbig...can't say I was smart...but I sure wish I could remember a quarter of what I knew.


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## vlmarshall (Nov 10, 2009)

I remember then the first hard drives hit the market." $1000 for a megabyte of storage?? Why would anyone want to put all of their programs in their computer at once? Mine are fine in these boxes of 5 1/4" floppies. Who even OWNS a whole megabyte of programs? " ;D


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## black85vette (Nov 10, 2009)

zeeprogrammer  said:
			
		

> itowbig...can't say I was smart...but I sure wish I could remember a quarter of what I knew.



AMEN!!!  Learning wasn't all that hard. It is the remembering part that gets me.

I took my first programming class on an RCA mainframe. It had so little memory that we could not compile programs other than assembly language. COBOL and FORTRAN were too big. You loaded your punch cards and at night they sent them over a very slow data line to a bigger mainframe. In the morning you got a print out of all your errors.  You fixed as much as possible and loaded the new stack that night and repeated the process. So it was a one day turn around for every time you needed to compile or make a change.


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## black85vette (Nov 10, 2009)

Vernon  said:
			
		

> I remember then the first hard drives hit the market." $1000 for a megabyte of storage?? Why would anyone want to put all of their programs in their computer at once? Mine are fine in these boxes of 5 1/4" floppies. Who even OWNS a whole megabyte of programs? " ;D


Yep. Megabytes seemed so far away.

Not only were the little floppies great in their hard cases but you could have the entire operating system, your applications software and all of your data files on the one disc. With some .bat files I had it set up to put the disc in and turn on the computer. It would boot, load the app and open the data file. You were ready to go.


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## GailInNM (Nov 10, 2009)

zeeprogrammer  said:
			
		

> Lucky you! My wetware has gone to LIFO. :big:



Mine has turned into write only memory.

Gail in NM


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## black85vette (Nov 10, 2009)

GailInNM  said:
			
		

> Mine has turned into write only memory. Gail in NM



We refer to that as a WORN drive. Write Once Read Never.


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## GrahamC (Nov 10, 2009)

My first exposure to computers was batch programming with punch cards or pencil marked cards on an IBM 1130 with a whopping 16K words of magnetic core memory. Programming was done in APL, Fortran, Cobol, or Basic. You submitted your program during the day, the operator would run the program over night and return your punch cards and printout in the morning. That was in the late 60's

After that came DEC PDP 8's and 10's, IBM 360's. I have many fond memories of having to key in a boot strap loader by hand using the front panel switches on the PDP-8's - the boot strap loader would run and allow the real program to be read off of paper tape feed through a reader on a KSR-33 model Teletype.

When microprocessors hit the market I got started with the intel 4004, moved on to the 8008, then the 8080 etc etc. I also messed around with the Motorola processors 6800, 6801, 6802, 6808, 68000 etc. First computers built with these chips often had key switches for input and LED's for output. If you where lucky you may have had a teletype for input and output or may have modified an IBM Selectric typewriter for printed output. A cassette drive for storing and loading programs was a big step up from key switch entry, eight inch 100 kilobyte floppy drives where a huge step up, 5-1/4" drives where a major advancement in miniaturization as where memory chips with more than a few hundred bytes of storage.

I well remember the s-100 bus and also the SS-50 with its ss-30 daughter i/o daughter boards. Heathkit had it's own 50 pin proprietary bus in it's H-8 computer.

The things we take for granted today - my 15 year old Hewllet Packard 48G calculator has more memory (32 kilobytes) and a faster processor speed than the Heathkit H8 computer I had in the late 1970's and only cost 1/10 as much.

Now we have desktop (and laptop) computers with 3+ Ghz processor speeds, 4 gigabytes of RAM, 500+ gigabyte hard drives, extreme high resolution graphic cards, sound cards which put some stand alone mid range stereo systems to shame and a network connection to world wide networks and near instant communication around the word all day every day for a fraction of what the high end s-100 bus 10 mhz Z-80 processor with 64 kilobytes of memory with simple graphics would have cost just over 25 years ago. Progress - all that and I still can't program my digital answering machine without spending 45 minutes reading the damn manual!

cheers, Graham in Ottawa Canada


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## GailInNM (Nov 10, 2009)

I started on an IBM 1620. It was a SIX bit word machine with ferrite core memory and a card punch and reader. Started with machine language and then assembler and finally Fortran IV on it. It was most notable as being the first IBM machine that did not use any empty state devices, vacuum tubes for you youngsters who are not up on your history.

Built a 8008 machine which started out with 1K of memory and a 350 kHz clock. Eventually got it up to 8K and a 500 kHz clock. Started out with just front panel switches and LED's, but at the end I had a surplus 60 WPM teletype machine with a tape punch and reader on it. Of course this was a 5 bit code, so for program loading and storage on tape, it took two characters and I used the 5th bit to indicate a hi or low nibble. That was really living.

The first serious program I wrote on it was an assembler so I did not have to program in binary (actually I used octal). Then with the assembler in place I wrote GOSUB, which was of course Gail's Own Screwed Up Basic.

Along the way I put in some read only memory using 256 bit fusible links chips. You learned to write really tight code with those. And check it twice, or more, before you started to blow fuses. 

All the boards were laid out on 10 x 10 grid paper with colored pencils for two sides. Then the holes were transcribed to another sheet of velum and glued to the board blank with rubber cement. All the holes were drilled on a drill press and after cleaning the board, all the traces were marked in by hand with a Sharpie marker for resist and etched. 

I still have Confucius, the computers name. I always wanted to say "Confucius says". A lot of parts were raided for later projects, but it is mostly intact. I will let the kids throw it away after I die. 

I don't miss the good old days, but I sure do miss the energy and dedication I had in the good old days.

Gail in NM


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## zeeprogrammer (Nov 10, 2009)

GailInNM  said:
			
		

> I don't miss the good old days, but I sure do miss the energy and dedication I had in the good old days.
> Gail in NM



Indeed.


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## black85vette (Nov 10, 2009)

GailInNM  said:
			
		

> You learned to write really tight code with those. And check it twice, or more, before you started to blow fuses.
> Gail in NM



Don't see tight code any more!  In an attempt to keep the amount of code under our 10k core memory we also wrote some self modifying code. Let you reuse some sections but was a real PITA to debug especiallly in machine language.

Dealing with binary, octal and hex ended up being useful to me. Now I am a network engineer and use it all the time in subnetting, net masks, and access control lists.

This has been fun. Would not have guessed we had this many old closet geeks lurking about! It has been great hearing from all of you. :bow:


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## zeeprogrammer (Nov 11, 2009)

Apple SOS


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## black85vette (Nov 11, 2009)

Trout; some great memories there. I can imagine working for Tandy at that time was pretty exciting.  I also had a TRS-80 and built a 3rd party disc drive controller because I had access to Shuggart disc drives. The controller extended the bus and had a couple of interfaces on it. But having the floppies is what made it fun and reliable.

I worked for Xerox at the time in the Office Products Division. Which was pretty everything except copiers. They couldn't decide which OS was going to win so they came out with the 820 II PC which had two processors and could run CPM and MSDOS. It was actually a pretty good machine and built as a business machine rather than home hobbyist. Xerox made some good acquisitions but failed to use them strategically. They bought Shuggart disc drives and then Diablo printers so they had some of the best equipment. But it was tough to fight Big Blue in the computer arena.


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## kvom (Nov 11, 2009)

> started on an IBM 1620. It was a SIX bit word machine with ferrite core memory and a card punch and reader.



I also started on this machine. One of its interesting features was that it used base-10 arithmetic with variable length operands, so you could multiply 100-digit integers. I used both assembler and Fortran on this machine. The programs were keypunched, and then the output could either be typed on the console selectric typewriter, or more frequently punched onto cards. The punched card deck would then be printed using an IBM accounting machine that was "programmed" using plug boards.

Other machines of this era were the 7044, on whichy we used assembler and Fortran. This was late 60s technology.


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## DickDastardly40 (Nov 11, 2009)

Poke 16514110 ;D


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## GrahamC (Nov 11, 2009)

Troutsqueezer  said:
			
		

> See if you remember any of these which I recall purely from memory which is pretty much an output-only device these days. I can recall numerous versions of CPM (Pickles and Trout - no relation - comes to mind) TRSDOS (trash dos), NEWDOS, DOS+, DOS80, LDOS, and even SteveDOS. Yes, Steve came out with his own DOS. I don't know who Steve was but his OS became somewhat popular. The only problem was, Steve's DOS used to step the floppy drives too fast on Tandy's Model Two 10" floppy bays and cause cyclic redundancy checksum errors. As you might expect, customers were not happy when told the problem was not Radio Shack's and they would have to pay for a service call.



Off the top of my head:

CPM80 - I recall many late nights hacking the basic CPM OS, building new drivers and integrating into the OS in order to get the OS running on a new piece of hardware. I still have a box of 8 inch disks in the book case with some of that stuff on. It will get trashed one day after I am gone but not before. I haven't seen an 8" floppy disk drive in over 15 years. The disks may not even be readable any more.

HDOS and HT-11 - Heathkit had their own OS's for their computers HDOS for the 8 bit machines and HT-11 for their PDP LSI-11 clone. HDOS was a very sophisticated OS patterned after DEC's RT-11 or RSX-11. Sadly it didn't catch on and CPM80 soon took over on the 8 bit machines

OS/8 - DEC's OS for the PDP-8

TOPS-10 - DEC's OS for the PDP-10

RT-11, RSX-11, RSTS/E, Ultrix-11 (and others) OS's for DEC's PDP-11 series of computers.

VMS and OpenVMS - DEC's OS for their VAX machines.

CPM80 - became the most popular 8 bit OS for 8080 based machines

CPM86 - CPM80 bigger brother ported over for the new 8086/8088 machines. As we all know IBM-DOS aka MS-DOS won out.

and lets not forget the 6800 series of cpu's

MIKBUG - a basic ROM basic OS for 6800 computers

MDOS - Motorola Operating System

OS-9 and Uniflex where others.

All of these where most of the ones I had some contact with over the early years and it is by no means and exhaustive list. This got me to thinking and doing a few Google searches. I came up with this link for OS's for micros from which I recognize many but certainly not all:

http://www.csee.wvu.edu/~jdm/classes/cs258/OScat/micros.html

cheers, Graham in Ottawa Canada


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