I would very much like to hear about the things you make with the many boards/kits/chips you are fond (and proud) of ordering. The name "Leon Heller" comes up frequently on the internet but it is almost always in the context of something you have on order, or have just received. That may be of passing interest, but it would be much more interesting to learn what you've created, how you did it, how well it worked, etc. For example, what have you made with your Due? Anything clever you can share? Obviously this isn't the forum - or at least the thread for that. But perhaps you've described such things elsewhere?
I just like playing with the latest stuff, as an intellectual activity. I'm not very well from time to time (temporal lobe epilepsy with seizures every couple of hours for several days every few weeks), and it helps to pass the time.
There is unquestionably a delight in ordering a new board type, powering it up, and seeing it do things. It is incredible to see how far technology has come.
Back in the day, hardware was huge and expensive but the μP manual was just a pamphlet. Nowadays the hardware is tiny and cheap but the chip manuals are 1000+ pages each. Digging in and digesting all that info until one can be productive on a new platform will give anyone a fit.
ST is a typical example. They have a nice selection of very low-cost development boards for their very cheap ARM Cortex chips. The chips can look deceptively simple, with as few as 20 pins, but the user manuals run to over 1000 pages.
Back in the pre-history of the human race, before there was an internet or a Propeller or an Arduino or even a Parallax Inc. Leon was the author of "Understanding the 68000". In 1984 I believe.
I have great respect for that.
No matter how old we get we are still exploring new toys out of curiosity and, well, just for fun. Even if we don't get to build any new Earth shaking new gadgets with them.
On a more contemporary note, Leon has often made comparisons between the Propeller multi-core concept and that of the XMOS devices. I think these are quite appropriate comparisons. There have been precious few other devices to make such comparison with.
These comparisons are even more appropriate when thinking of the hopefully coming P2.
Understanding the 68000 Hardcover – 1 Nov 1984
by Leon Heller (Author)
Product details
Hardcover: 192 pages
Publisher: Century (1 Nov. 1984)
Language: English
ISBN-10: 0712605851
ISBN-13: 978-0712605854
Product Dimensions: 21.4 x 13.4 x 1 cm
Average Customer Review: Be the first to review this item
Amazon Bestsellers Rank: 4,084,268 in Books (See Top 100 in Books)
Motorola did a fantastic job of the 68k, it's a real pity IBM didn't choose it for the PC. I always meant to get hold of a Coldfire chip at some stage.
Yes. This book had a main impact on my life. And it was a Paperback. Taped and glued all over. One of those bibles I kept and read all the time, before Internet and PDF we needed BOOKS. And staples of magazines like Analog and such.
I remember Micro Focus COBOL coming with 10+ Books, three feet book space required. Somewhere around the same time. Early 80'.
So @Leon is 'the man' for me and I do not complain about his constant pushing of other not to be named brands.
There was just one other book I had that got more worn out. It was a early publication about the first 386 (286?) and how to get to 32 bit modes. Hand coded boot sectors on floppy disks. Compared with the 68000 the x86 was brutal to you while writing assembly.
Long time ago. At that time I hated the IBM/350 assembler I had to work with, but loved the 68000 one. Like @evanh said - it is a real pity IBM went for the x86.
It is possible I do like PASM so much because of my beloved 68000. Simplicity.
It was LEO's first transistor machine. It was much faster than the previous models and I designed a circuit to slow the pulses down so that engineers could hear what was going on in the CPU. Previously they could just feed the pulses straight into an amplifier. I couldn't use a digital divider (too expensive) so I simulated a unijunction transistor (they had just been invented and weren't commercially available) using a pair of BJTs and used two of those to give a divide by 100 function, with an amplifier and speaker. It went into production and I subsequently saw my PCB mounted in the cabinets of machines on the shop floor.
I like it, the young Leon working on the Leo computer, how appropriate.
In case anyone does not know the original Leo was the first ever computer used for commercial business applications.
We are honoured with Leon's presence here.
It amazing to think that people used to listen to their programs executing.
Back in the 1970's, as a kid, I built my first TTL circuit. A digital clock with Nixie displays. Naturally when I finished construction it did not work. I was about to throw it in the trash.
Then my father, who knew nothing of such new technology, suggested I hook up an ear piece to some important signals and listen to it "ticking". In no time at all it was working!
Back in the day processors were not so fast. Execution time in kilohertz or megahertz.
You can easily tap into signals on the machine, divide it down to audio, and all of a sudden you can hear your program run. You can hear the familiar sounds of it's boot sequence. You can hear when it gets stuck in a loop. All kind of things.
Even recently you could put an FM radio next to your computer and listen to the different noises it makes as it executes.
Heck even now, I can tell what my PC is doing by listening to the little noise that changes in the headphones as I watch YouTube videos and such.
Given your book on the 68000 did you ever work with Nick Tredennick? (http://en.wikipedia.org/wiki/Nick_Tredennick) As far as I know he's still living here in the Bay Area, and a friend of mine worked with him NexGen and his consulting business a while back.
Many years ago I had a colleague who put an R/2R DAC on the address bus of his Z80 based CP/M system. It drove a moving coil analogue voltmeter. But seeing what the average voltage was you could diagnose where the software was spending most of its time. A voltage near 5v meant it was in the EPROM-based BIOS; somewhere around 4v meant it was inside CP/M; around 1v meant it was down in the TPA and executing user code.
No, I don't remember the name. I knew one of the other designers slightly but I've forgotten his name. He moved into marketing and was based near me here in the UK, and I approached him to get permission to include some of Motorola's own diagrams.
Leon - o.k. I went to Carnegie Mellon and one of the undergraduate projects they used to do was to implement a subset of the 68000 in bit-slice logic. I felt unfortunate because I was looking forward to that, and then they changed the project right when I took the class. I was lucky to have one of the early Macs at school though which was probably because my father wanted an excuse to replace it with a newer model. But that gave me and some classmates the chance to do some 68k coding without having to fight for access in a computer lab.
Nick wrote a book "Microprocessor Logic Design: The Flowchart Method" where he described his approach to design. I didn't see it until years later though when a coworker showed me a copy.
A wealth of knowledge and experience is contained in these forums. Joining this community and checking it often has already given me so many answers, sometimes to questions I did not even know existed. Thank you all for sharing your experiences.
That board resembles the register flip-flop boards used in the Collins 8400 computer. One of those and two transfer gate boards made one bit of a register.
Many years ago I had a colleague who put an R/2R DAC on the address bus of his Z80 based CP/M system. It drove a moving coil analogue voltmeter. But seeing what the average voltage was you could diagnose where the software was spending most of its time. A voltage near 5v meant it was in the EPROM-based BIOS; somewhere around 4v meant it was inside CP/M; around 1v meant it was down in the TPA and executing user code.
I saw a similar idea using two 8 bit dac's on a 16 bit address bus with the outputs going to the X and Y inputs of an oscilloscope. Very helpful for debugging.
Having only read bits and pieces of this thread (do to time and the length of the thread):
Has Chip made any progress on this new design? It seems more reasonable than the original Prop2 design by a long shot.
And wow, I did not realize that Leon wrote one of the books I have always kept dear. I must give my respect to you Leon.
The 680x0 series is easy to program for in assembly, or even machine language (good instruction formatting), despite having a large instruction set. Nearly as orthogonal and simple as the ARM.
_______________________________________________________________________________________________ @Heater:
The entire ARM instruction set (up through and including ARMv7):
ADC Rd,Rs,Rs ;Add with carry.
ADD Rd,Rs,Rs ;Add.
B offset ;Branch.
BL offset ;Branch with link.
BIC Rd,Rs,Rs ;Bit Clear.
CMN Rs,Rs ;Compare Negitive.
CMP Rs,Rs ;Compare.
EOR Rd,Rs,Rs ;Exclusive OR.
LDM Rd,{Rlist} ;Load Multiple.
LDR Rd,Offset ;Load Registor.
MLA Rd,Rs,Rs ;Multiply and Accumulate.
MOV Rd,Src ;Move.
MUL Rd,Rs,Rs ;Multiply.
MVN Rd,Src ;Move Negitive.
ORR Rd,Rs,Rs ;OR.
RSB Rd,Rs,Rs ;Reverse Subtract.
RSC Rd,Rs,Rs ;Reverse Subtract with Carry.
SBC Rd,Rs,Rs ;Subtract with Carry.
STM {Rlist},Rs ;Store Multiple.
STR D,Rs ;Store.
SUB Rd,Rs,Rs ;Subtract.
SWI N ;Software Interupt.
SWP ;Atomic Swap.
TEQ ;Test For Epual.
TST ;Test.
The above is from the top of my head with out reference.
All instructions are conditional (the default condition being always), and it is optional to affect the flags.
Also shifts and rotates can be applied to most instructions.
As you know the original P2 design went off the rails in a big way. We don't get so much news on progress now a days. Chip made a serious restart. I am confident the outcome will be good.
As you know the original P2 design went off the rails in a big way. We don't get so much news on progress now a days. Chip made a serious restart. I am confident the outcome will be good.
Understood. I am looking forward to the new Propeller when ever it is done.
Yes some of the documents are a little arcane. I do not understand why they attempt to make the ARM look bad like that, ARM is one of the simplest ISA's I know.
Comments
I would very much like to hear about the things you make with the many boards/kits/chips you are fond (and proud) of ordering. The name "Leon Heller" comes up frequently on the internet but it is almost always in the context of something you have on order, or have just received. That may be of passing interest, but it would be much more interesting to learn what you've created, how you did it, how well it worked, etc. For example, what have you made with your Due? Anything clever you can share? Obviously this isn't the forum - or at least the thread for that. But perhaps you've described such things elsewhere?
There is unquestionably a delight in ordering a new board type, powering it up, and seeing it do things. It is incredible to see how far technology has come.
Back in the day, hardware was huge and expensive but the μP manual was just a pamphlet. Nowadays the hardware is tiny and cheap but the chip manuals are 1000+ pages each. Digging in and digesting all that info until one can be productive on a new platform will give anyone a fit.
Back in the pre-history of the human race, before there was an internet or a Propeller or an Arduino or even a Parallax Inc. Leon was the author of "Understanding the 68000". In 1984 I believe.
I have great respect for that.
No matter how old we get we are still exploring new toys out of curiosity and, well, just for fun. Even if we don't get to build any new Earth shaking new gadgets with them.
On a more contemporary note, Leon has often made comparisons between the Propeller multi-core concept and that of the XMOS devices. I think these are quite appropriate comparisons. There have been precious few other devices to make such comparison with.
These comparisons are even more appropriate when thinking of the hopefully coming P2.
by Leon Heller (Author)
Product details
Hardcover: 192 pages
Publisher: Century (1 Nov. 1984)
Language: English
ISBN-10: 0712605851
ISBN-13: 978-0712605854
Product Dimensions: 21.4 x 13.4 x 1 cm
Average Customer Review: Be the first to review this item
Amazon Bestsellers Rank: 4,084,268 in Books (See Top 100 in Books)
http://www.amazon.co.uk/Understanding-68000-Leon-Heller/dp/0712605851
It was actually a paperback. That might be a library version that was rebound.
I want a copy. It is too bad Amazon doesn't have it. The Sega Saturn is my favorite game system and it uses the 68000 for its sound controller.
Yes. This book had a main impact on my life. And it was a Paperback. Taped and glued all over. One of those bibles I kept and read all the time, before Internet and PDF we needed BOOKS. And staples of magazines like Analog and such.
I remember Micro Focus COBOL coming with 10+ Books, three feet book space required. Somewhere around the same time. Early 80'.
So @Leon is 'the man' for me and I do not complain about his constant pushing of other not to be named brands.
There was just one other book I had that got more worn out. It was a early publication about the first 386 (286?) and how to get to 32 bit modes. Hand coded boot sectors on floppy disks. Compared with the 68000 the x86 was brutal to you while writing assembly.
Long time ago. At that time I hated the IBM/350 assembler I had to work with, but loved the 68000 one. Like @evanh said - it is a real pity IBM went for the x86.
It is possible I do like PASM so much because of my beloved 68000. Simplicity.
Enjoy!
Mike
.
then the http://www.amazon.com/Apple-Machine-Language-Don-Inman/dp/0835902307
We had the black Bell and Howell Apple II's with Integer Basic, so no Assembler available. Funnily enough, remember trying to make a speech digitizer by running a peek/poked assembler loop that read the audio in to the 48K memory from a tape recorder. Wasn't sure it would work, and of course if didn't. But those were the great old highschool days when there were just a ton of different computers around, all running on 6502, Z80, 6809, 68000/8, etc.
Dreaming back then was that sometime in the future we might get up to 100 mhz, or maybe before I died, 1000
Now its just x86 and the Pi/ARM primarily... but you can buy a dual-core Ghz+ throwaway track phone for $25 at the grocery store?
Long before that, when I was a student at English-Electric-Leo, I worked on the LEO III mainframe.
On a shelf in the library I have this....
...a board from a Leo III
What would they listen for?
I like it, the young Leon working on the Leo computer, how appropriate.
In case anyone does not know the original Leo was the first ever computer used for commercial business applications.
We are honoured with Leon's presence here.
It amazing to think that people used to listen to their programs executing.
Back in the 1970's, as a kid, I built my first TTL circuit. A digital clock with Nixie displays. Naturally when I finished construction it did not work. I was about to throw it in the trash.
Then my father, who knew nothing of such new technology, suggested I hook up an ear piece to some important signals and listen to it "ticking". In no time at all it was working!
Who needs oscilloscopes and such like?
You can easily tap into signals on the machine, divide it down to audio, and all of a sudden you can hear your program run. You can hear the familiar sounds of it's boot sequence. You can hear when it gets stuck in a loop. All kind of things.
Even recently you could put an FM radio next to your computer and listen to the different noises it makes as it executes.
Heck even now, I can tell what my PC is doing by listening to the little noise that changes in the headphones as I watch YouTube videos and such.
Given your book on the 68000 did you ever work with Nick Tredennick? (http://en.wikipedia.org/wiki/Nick_Tredennick) As far as I know he's still living here in the Bay Area, and a friend of mine worked with him NexGen and his consulting business a while back.
-Keith
Many years ago I had a colleague who put an R/2R DAC on the address bus of his Z80 based CP/M system. It drove a moving coil analogue voltmeter. But seeing what the average voltage was you could diagnose where the software was spending most of its time. A voltage near 5v meant it was in the EPROM-based BIOS; somewhere around 4v meant it was inside CP/M; around 1v meant it was down in the TPA and executing user code.
No, I don't remember the name. I knew one of the other designers slightly but I've forgotten his name. He moved into marketing and was based near me here in the UK, and I approached him to get permission to include some of Motorola's own diagrams.
I've just remembered his name - Tom Starnes:
http://www.objective-analysis.com/Contact_Us.html#Tom_Starnes
Nick wrote a book "Microprocessor Logic Design: The Flowchart Method" where he described his approach to design. I didn't see it until years later though when a coworker showed me a copy.
That board resembles the register flip-flop boards used in the Collins 8400 computer. One of those and two transfer gate boards made one bit of a register.
I saw a similar idea using two 8 bit dac's on a 16 bit address bus with the outputs going to the X and Y inputs of an oscilloscope. Very helpful for debugging.
re: On a shelf in the library I have this....
Cool!
I've got several bits and pieces on that shelf.
A 16x24 core store made by Plessey...
A module from a Burroughs B200...
Has Chip made any progress on this new design? It seems more reasonable than the original Prop2 design by a long shot.
And wow, I did not realize that Leon wrote one of the books I have always kept dear. I must give my respect to you Leon.
The 680x0 series is easy to program for in assembly, or even machine language (good instruction formatting), despite having a large instruction set. Nearly as orthogonal and simple as the ARM.
_______________________________________________________________________________________________
@Heater:
The entire ARM instruction set (up through and including ARMv7):
ADC Rd,Rs,Rs ;Add with carry.
ADD Rd,Rs,Rs ;Add.
B offset ;Branch.
BL offset ;Branch with link.
BIC Rd,Rs,Rs ;Bit Clear.
CMN Rs,Rs ;Compare Negitive.
CMP Rs,Rs ;Compare.
EOR Rd,Rs,Rs ;Exclusive OR.
LDM Rd,{Rlist} ;Load Multiple.
LDR Rd,Offset ;Load Registor.
MLA Rd,Rs,Rs ;Multiply and Accumulate.
MOV Rd,Src ;Move.
MUL Rd,Rs,Rs ;Multiply.
MVN Rd,Src ;Move Negitive.
ORR Rd,Rs,Rs ;OR.
RSB Rd,Rs,Rs ;Reverse Subtract.
RSC Rd,Rs,Rs ;Reverse Subtract with Carry.
SBC Rd,Rs,Rs ;Subtract with Carry.
STM {Rlist},Rs ;Store Multiple.
STR D,Rs ;Store.
SUB Rd,Rs,Rs ;Subtract.
SWI N ;Software Interupt.
SWP ;Atomic Swap.
TEQ ;Test For Epual.
TST ;Test.
The above is from the top of my head with out reference.
All instructions are conditional (the default condition being always), and it is optional to affect the flags.
Also shifts and rotates can be applied to most instructions.
Here is a good reference, a lot longer than needed though good for those that are new to ARM:
http://www.heyrick.co.uk/armwiki/Main_Page
As you know the original P2 design went off the rails in a big way. We don't get so much news on progress now a days. Chip made a serious restart. I am confident the outcome will be good.
The ARM instruction set may be simple if you can find that simplicity. But a google search always gets me to a document like this http://simplemachines.it/doc/arm_inst.pdf or this "quick reference" http://infocenter.arm.com/help/topic/com.arm.doc.qrc0001m/QRC0001_UAL.pdf. Any of which give me a migraine far worse than x86 ever did.
Again for a simple reference see:
http://www.heyrick.co.uk/armwiki/Main_Page
Look at the Instruction set subsection.