Ed Roberts, Personal Computer Pioneer, 1941-2010

A user writes "CNET and the Huffington Post both report the death of Henry Edward Roberts, best known to all of us as the inventor of the Altair computer, at the age of 68 from pneumonia. As it happens, I never got to use an Altair, but I did meet Ed once, back in the mid-1980s. Since that time, I've never referred to the Altair bus as the 'S100' bus, since I agree with him that an inventor is entitled to name his invention." Updated 7:40 GMT by timothy: Roberts was 68, not 88 as originally stated; thanks to the readers who pointed out the typo.

88? Not that lucky.

[Animats]

2010 - 1941 = 69

Re:A fitting tribute

[Anonymous Coward]

never seen an ASCII goatse before. Clever. Now go away.

Nice information at Digibarn Computer Museum

[ckblackm]

http://www.digibarn.com/stories/MITS/index.html [digibarn.com]

it's all in the 8's

[goombah99]

the altair 8800 ran on an 8080 and you programmed it in octal.

Of course it was not octal. it was binary. there were 16 switches across the front.

these days most people represent binary numbers as hex. Ever wonder why Octal used to be so much more popular? when you write octal numbers they are really inconvenient so why use them?

Well the answer is, if you are keying in binary number in one switch at a time you can do it lightning fast in octal but not in hex.

with octal you use your middle, index and ring fingers and you can whip the switches up an down. While you do have four fingers you can't easily use all four fingers to slap the switches

try it, your fingers are not equally long, and it's hard to retract your fingers in all 16 possible positions.

octal is easy.

So you programmed altairs in octal.

the altair I used did not even have a boot loader. you just toggled in the binary to enter the boot loader then once you had that in you could read the casstte which had a longer more sphisticated boot loader. which then read in BASIC.

there was no OS. if you wanted an OS, you wrote it in basic as you needed it.

to enter the program into memory the altair used an interesting trick. the front panel switches could set the address counter to an address, which could then be incremented. You put the computer into a wait state to enter the data to be written to the memory, then advanced the address counter.

by the way the 6502 was a much better processor with a simpler but more sophisticated instruction set.

one reason I think the 8080/Z80-series beat the 6502 was an early version of the megahertz myth. The 4mhz base clock rate of the z80 was faster than the 6502's base clock rate of 1Mhz. But the z80 used 4 clock cycles and a few wait states for most instructions. the 6502 complete nearly every instruction in one instruction.

if only the altair had been 6502 based.

(the 6502 came out later in time of course, so it's understandable.. and there was a 6800-series version of the altair that never caught on).

yay for a renaissance man who touched many

[1 a bee]

This man did many things and touched many lives. Bill Gates's and Paul Allen's, included. FTA:

Roberts founded Micro Instrumentation and Telemetry Systems, which sold the kits. A young Gates and Allen would later found their fledgling Microsoft firm in Albuquerque, N.M., where MITS was based, and provide a computer language that helped hobbyists program and operate the Altair.

After selling his company, he tries both farming, and then medicine. (He's in his 40s at this time.)

He sold his company in 1977 and retired to a life of vegetable farming in rural Georgia before going to medical school and getting a medical degree from Mercer University, in 1986.

Roberts worked as an internist, seeing as many as 30 patients a day

Talk about multi-dimensional..

Re:it's all in the 8's

[noidentity]

I used to think the 6502 was superior for its lower clocks-per-instruction, but I've since learned more. The 6502 uses a two-phase clock, so it's really double the apparent clock rate. The Z-80 uses a higher clock, but runs memory at a lower rate. That was one of the limiting factors of those days, the speed of the external bus. So you could use the same speed memory with a 4 MHz Z-80 as with a 1 MHz 6502 (don't know the exact numbers, but it's basically like this). The Z-80 also had more registers and you could do many register-to-register operations, whereas on the 6502 you must use memory for things like ORing two values together.

That said, I much prefer the 6502 for its simple and clean instruction set, and the fact that it didn't use any microcode when decoding instructions. It feels like a RISC machine, while the Z-80 feels just like x86, as it's an extension of the 8080, itself not very elegant either. Things like two-byte relative jump instructions are SLOWER than three-byte absolute jumps, for example.

Re:Handheld Altair

[captjc]

I believe that Briel Computers, the guys who designed the Apple 1 replica, The Replica-1 computer and other cool kits are working on something similar. The first version was a standard ATX case that was shaped like a Altair and the front panels were a controlled by a reprogrammable Microcontroller acting as an 8800 emulator. I am not quite sure of the specifics. http://www.brielcomputers.com/altairpc.html [brielcomputers.com]

After looking on his site, it seems they are now working on something similar to a handheld Altair called the Altair 8800 Micro. http://www.brielcomputers.com/wordpress/?p=246 [brielcomputers.com]