About the writing...There appears to be a paragraph or two missing at the beginning of the article that sets the scene. The first sentence starts with "Most computers at that time". I guessed the setting was the late 1980s.
I was trying to understand who the players were. Mentioned were " Wilson, Furber and the rest of the team" but no context.
I noticed an inaccuracy about the IBM PC processor. The first PC used the 8088, the 8-bit data-bus version of the 8086.
Wait...I just noticed at the bottom of the article a page button where it says page 3 of 3. I arrived from a LinkedIn discussion group. I don't see paging buttons at the top of the article.
Extremely well done story, Peter. I enjoyed it. "It took four clock ticks to run a (68000) memory cycle." That told me something I didn't know about the evolution and inherent advantage of the ARM architecture, which I assume took one tick. Charlie Babcock, InformationWeek
The core of ARM was that it had to be cheaper than an off the shelf processor or else Acorn went bust. Thats why when Robin Saxby took over he needed to find a customer for the core as Acorn were not buying enough to keep going. Nokia told people to licence this as they were not paying for someone elses IP as it would mean GSM handset were going to be too expensive. TI licenced it and there history was written
Back in the days I worked at an early computer store, we ran a set of BASIC benchmarks originally published in BYTE magazine on the other computers in our store after we found our numbers agreed with BYTE's list of computers they ran on.
I further wrote a program to sort and rank the results (this being the days before VisiCalc) and one item I tracked (but did not sort on) was the processor the syetem used.
Were were looking to see who wrote the better BASIC interpreter, but were surprised when we saw processor stratification instead.
The 1 MHz 6502s were faster than the 4 MHz Z-80s, followed by the 4 MHz 8080s.
Looking into it, aside from the pipelined instructions, loads took 3 cycles on a 6502 while the Z-80 took 6, and the condition code was set automatically by the load instead of requiring another instruction like the Intels, I felt it was the reduced number of registers (6502 A, X & Y) (Z-80 A, BC, DE, HL + mirror set) helped as well. From my experience programming S/370 Assembler, I had seen too many cases of registers being swapped around, just to make use of register sets already being used, or for special purpose use, which in the end did not do much but chew up clock cycles. Given the reduced number of registers on the 6502, you made use of them for good purpose, you didn't calculate a value and let it hang in a register for K's of execution later until you whipped it out of seemingly nowhere (making debugging harder as well).
That made the 6502 far more efficient than the Intel processors, even though they ran at 4x the clock rate.
Yes I recall my days at ACORN and interaction with Herman, Roger and Steve.
I even recall Herman & my discussion about the daily calendar product that was to have 16 charter LCD displays from Hitachi and use there RT chip who we were connected with very closely for memory parts for our BBC and Electron
What a group and what an innovation company from the day one joined…looking back it was love of my life as I have not come across another company like it for pushing the envelope on daily bases. Gopro may today’s such leader
At ACORN, each one of us was doing 5 projects at any one time from network to making mouse using CCD sensors. I even tacked a research storage device where there head moved spirally to the center with removable 2in cartridge. This is before the 3.5in Discs became the norm
Oh I still have an Electron and it still boots-up and runs Basic, 6502 Assemble like no other product today to hack code in 5min and run 2MHz assembly in Basic. What a concept
Only good memories of my carrier and working with Herman, Roger Wilson (Sophie Wilson) and off course Chris Curry who we started a company called GSI out of his 40 bedroom Manson in Croxton Village together with Ram Banerji
ZahidOh I still have an Electron and it still boots-up and runs Basic+6502 Assemble like no other product today
The first project I worked on used the BBC microcomputer to do 3D spherical trigonometry using radio signals in real time to compute location - sort of a poor man's GPS.
What was astonishing was how fast floating point code written in Basic would run on this 8 bit 6502. I guess this was due to hand-crafted C or assembler floating point routines embedded in ROM but I still don't really understand how they made interpreted code run so quickly.
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
Brought to you by