April 2013 Meeting Notes

Compiled by Dave Jaffe

Contributions from Kevin Appert and others

SVFIG on Google+ Hangout- long url - tinyurl

Videos - morning (1:31:10) - afternoon (2:26:51)

09:45

Coffee and a Chat

10:00

Forth Instructions per Cycle > 1 - Alexey Chapyzhenka
Alexey will present his findings and discuss: Forth processors with FIPC > 1 (Forth Instructions per Cycle), instruction bundling, encoding, decoding, and execution.

Forth Quark combiner

Two references on the topic: 'Compiling Stack code on Register Machines'
Compilation of Stack-Based Languages, status April 1999

M. Anton Ertl. A new approach to Forth native code generation. In EuroForth '92, pages 73-78, Southampton, England, 1992. MicroProcessor Engineering.
M. Anton Ertl. Implementation of Stack-Based Languages on Register Machines. Dissertation, Technische University at Wien, Austria, 1996.

10:30

Registers as Stack Cache and Its Implications - Samuel A. Falvo II
"Topics I'd like to cover include (in no particular order):

Proposed Basic Algorithm
Benefits (stack manipulation words generally produce _zero_ code, frequent operations like + @ reduce to CPU-supported addressing modes).
Disadvantages (basic block boundaries needs to fix up stack image in RAM).
Example output: 6502, 80386, Data General Nova
Compiler Implementation Issues (expectation stacks, code backtracking and rewriting, strict interfaces between compiler and code generator, etc.)
Extensions to the concept: instruction scheduling as a separate pass to exploit superscalar architectures, optional static type checking, etc."

11:30

eP32 Stacks - CH Ting
"I can talk a little bit about the stacks in eP32."

Slides - 142 Kb pdf file

11:45

Lunch
We walked to and ate at the Treehouse.

13:00

Introductions, Announcements, Rumors, and Gossip

13:10

Stacks to Variables inside Graphical Haiku Forth - Brad Nelson
To squeeze greater performance out of Javascript and to support WebGL, Graphical Haiku Forth converts stack operations to variables. Brad will examine the method used in the current implementation and discuss its properties and limitations. Recent and coming enhancements to Haiku Forth will be discussed.

Forth Salon

14:10

Break

14:25

Review of Cool Product Expo & Robot Block Party - Dave Jaffe
Dave will review the product offerings at the recent Cool Product Expo and show some video from the annual Robot Block Party – both Stanford events.

Slides - 251 Kb pdf file

Cool Product Expo - 2013

Robot Block Party

TechHive Video Update

IEEE Spectrum

14:45

Design West 2013 - All present
The annual Embedded Systems Conference is now called Design West, held this past week at the San Jose Convention Center. We'll talk about what we saw and where the industry is headed.

15:00

Maker Faire Discussion - CH Ting
Ting wrote: "At the Faire, I will show a few simple tutorials and demos, basically for young people to use Forth on the Arduino. Let's determine what we need to take to the Faire."

15:20

Eternal Sorrow & Schubert - CH Ting
"I have reworked the video on Eternal Sorrow, based on a poem by Pai Ju-yi and songs by Schubert (Winterreise). It was actually sung in Chinese. I trimmed it down to about 40 minutes and added English subtitles to the existing Chinese subtitles.”

Random Access
Impromptu talks, amiable ambling discussions, sauntering through news://comp.lang.forth, and other conversations will be offered.

15:55

Clean Up

16:00

Adjourn