ajparent1/kb1gmx wrote:
Lee, You are far from alone on that. I have maybe a dozen boxes of
those that I've retained over the years. They tend to reflect my
interest in 8080/8085/z80 and other cpus of the day especially
software of all forms.
Byte, Kilobaud, DDobbs, S100 Micrcomputing, Microcomputing, QST
(also my interests with radio), Ham Radio, and Popular Electronics and
Radio Electronics.
I think the fascination for me is that I can read these old articles and *understand* them. They were written at a time when everyone was a beginner.
The chips were also more straightforward; the datasheets might be only a dozen pages.
Today, the computer journals are so obtuse that I can't make any sense of them. And the datasheets have become 1000-page incomprehensible monsters.
VTL, that was an interesting beast. It was when people were doing
TinyBasic and other small languages. Often the goal was fit it in a
1k or 2K eproms (2708 and 2716 in the day). I morphed VTL into a
command line monitor as a somewhat primitive script language and
operating environment.
VTL was not so much fast as strikingly compact. Less code more
speed.
For those who might be interested, VTL is an interpreter (like BASIC). The manual for it is here:
VTL took the "everything is an expression" route. Every line is of the form "line# variable=expression". All the letters A-Z are variables; but so are many of the punctuation symbols. But the punctuation symbols are "system variables" that do extra things. For example, ? is print, # is the next line#, * is end of memory, & is start of memory, etc. So...
#=number is your GOTO line#. #=1 runs the program from the beginning.
&=0 is clear program, because it sets the program size to zero.
*=0 exits VTL, by setting its size to zero.
IF is accomplished by a calculated GOTO. 0 is an illegal line#, so you can't GOTO it. So
20 #=(X=25)*50 means GOTO line 50 if X=25; else continue to the next line.
! is the last line#+1. So RETURN is #=! (GOTO the last line of the caller).
Peculiar; but it works!
Lee
--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
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Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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