It may surprise you “young” readers to hear that for many years there was no difference between a computer used for dedicated applications and one that could run different programs at different times! When Intel’s 8-bit 8008 gave way to the 16-bit 8086 they also produced the 8-bit-interface 8088; the next step had the 80286 but still had the (I believe 8-bit-interface) 80186; the 80286 led to the 386, and the 486. after “4” the marketing folks substituted “Pentium” for “5”; since then the non-dedicated program market has moved out of sight. Continue reading
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A new e-book?
In checking if this (newly moved) web site was coming up on search engines, I did a search for the title, C and the 8051. It was a surprise!
I have known for some time that my ex-publishers chose to (illegally) permit the third edition on Google books and that someone had scanned in the entire 4th edition (also illegally). After chafing for a bit and exploring what steps might be necessary to fight it, I decided it wasn’t worth the effort. Those who want to Xerox about 500 pages will find it costs as much or more than buying the official book and still leaves them without a cover or binding. Continue reading
When knowing Assembly Language is good
Is it vital to programming to know how the computer works? No…probably not with the high-end applications of today. I have only a vague idea of how WordPress is combining the pieces of this post onto your screen and have never made a study of HTML or PHP. But when you are working with low-end computers, closer to the actual machine operations, it can make a difference. Continue reading
Microcontrollers and Emulators
It has been quite some time since integration capabilities first allowed the processor, memory, and I/O to all go on one chip and the name changed from microprocessor to microcontroller.
The problem in the early days was the development process–it was quite feasible to get a large quantity of a device built with a fixed program permanently integrated (if you were using a micro in a high-volume application such as an engine controller in an automobile), but getting just one device with a new iteration of a program you were developing was a different matter. Continue reading
Development on a CRT
The biggest leap forward in software development for me was the shift to a development station consisting of a keyboard and a CRT (it was a custom unit produced by Intel in the days before the PC was in existance). It seems to me they cost several thousand dollars. As best I recall the first ones I used were large dark blue boxes that included a slot for a 8″ floppy disk. The marvel was that one could make changes to the assembly (mnemonic) code and reassemble without having to repeat all the steps. If the assembler detected errors you could see them at once and it was a much simpler matter to make a fix or two and immediately re-assemble to see if everything was OK. On top of that the magnetic storage was so much easier and quicker than punched tape. Continue reading
Microprocessors
Those of us old folks who got in on the start of embedded controllers can remember when small-room-sized computers started to have competition from Minicomputers. They were built of multiple circuit boards in an enclosure about the size of a large microwave oven and were the first computers to be uksed for more control-related applications.The computing was done with core chipsets that were 4-bits wide (extremely low level of integration by today’s standards, but the available technology drove the applications). If you wanted a 12-bit processor you laid out 3 sets of processor chips (or 4 sets for 16-bit processing) on circuit boards.
About that time Intel and Motorola (and was it Fairchild and RCA?) began to develop more highly integrated ICs that held more of the processor on a single chip, called microprocessors. Continue reading
Revising a very old web site
Cleaning Up!
I have finally gotten a way to access my old web information and will shortly include the original information as well as a blog/comment thread. I have fixed the ancient links that no longer lead to the right supplier pages. I may even some day get to finishing the answers to the book questions!
Talk to me
I have no feedback about my book–who is buying it, what they think of it, and what is most useful. I encourage you…if you have an interest in 8051-family development…to comment here. I have plans to regularly blog about the history of embedded micro development (you wouldn’t believe how ancient I am) as well as posting comments that were not suitable to the book itself. The only feedback I get these days is the sales numbers from the printer (a few tens of copies each month), so I “covet” your comments. Continue reading