June 11th, 2015 ~ by admin

Dallas: Reaffirming the Viability of the 8-bit Processor

The introduction of the Dallas Semiconductor DS87C520 reaffirms the viability of 8-bit processors for new and demanding applications.  Those were the words written about the the Dallas DS87C520 (and its ROMLess version the DS80C320) in 1994. The Intel MCS-51 architecture it was based on had been released 13 years prior, in 1981 and ran at up to 12MHz.  By 1994 the Pentium had been released, with speeds of up to 100MHz.  Full 64-bit processors were also available, yet the 8-bit processor continued to hold on, and grow.

Dallas Semi. was founded in 1984, by former Mostek employees.  Their first products were lithium battery backed SRAMs, a product pioneered by Mostek.  Dallas added power saving and sensing circuitry to them though, greatly enhancing their usefulness.  In 1987 they combined with with an MCS-51 microcontroller to make the DS5000, which ran at 16MHz and provided battery backed SRAM.

With the release of the DS87C520 in 1994 they redesigned the MCS-51 core, allowing it to complete a machine cycle in 4-clocks vs the original 12.  They were plugin compatible, providing a simple speed up for 8051 systems.  Max clock was also raised, to 33MHz as well as additional interrupts, 16K of EPROM, an extra 1KB of SRAM and many power saving features/modes.  Other companies (such at Philips, and Atmel) began to also make enhanced 8051s, including things such as Flash memory and expanded instructions/features.

Its now 2015, and the 87C520 continues to be made, as does hundreds of other MCS-51.  It was surprising in 1994 that the 8-bit processor continued to be viable, and perhaps to some, even more so, that 21 years later, it is still viable, and shows no signs of slowing down.  The recent push into the Internet-of-Things (IoT) market has 8-bit MCUs in Internet of Things yet again.  While many companies have marked numerous 16-bit and 32-bit designs as ‘a migration path from 8-bit’, that migration is yet to be seen.  There simply is no reason, no need, and no desire to plug a 32-bit processor in where an 8-bit processor, implemented in a few thousand transistors, will do nicely.


April 12th, 2015 ~ by admin

Processor Die Photos by Christoph Morlinghaus

Christoph Morlinghaus in front of the very large prints of an Intel 486DX and Motorola 68030

Christoph Morlinghaus in front of the very large prints of an Intel 486DX and Motorola 68030

I recently had the pleasure of helping noted photographer Christoph Morlinghaus with a die photo project.  Christoph takes photos with a large format 8×10 film camera, and wanted to do some of processor dies, so the museum sent him off a box of chips. After a lot of work decapping and cleaning the chips, as well as finding ones with the most interesting dies, Christoph was able to take some stunning shots, no easy feat with the long exposure times required for such a camera.  Exposure times for these shots can run into the minutes, and even something as minor as a truck driving by can create enough vibration to ruin the shot.  Dies also had to be selected to show a variety of detail, colors, and be big enough to take a picture of, ideally a half inch on a side or better.  You can view the results here on Morlinghaus.com. Some very large format prints are currently on display at the Snap! Gallery in Orlando Florida as well.

Christoph did 7 total die shots of a variety of processors spanning 15 years of computing.  Dies included are: Intel 186, 486 and Pentium (P54CS), Motorola MC68020 and MC68030 as well as a Cyrix Media GXm and Cx486DX2. A 17″x22″print of each was donated to the CPU Shack, which are now framed and hanging, where they make a very nice display, as well as truly artistic pieces.


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