Z TIPS: AC, Version 1.1, has been placed in ZRDOS (or ECHELON) directory area
of Z-Nodes (AC works with ZRDOS and ZRDOS Plus only). ZRDOS author, Dennis
Wright, changed archive copy program by eliminating prompt if file exits on
destination. Now simply using option /a causes changed files to be
automatically copied from source to destination directory. Using /an with
Version 1.0 did the same thing but file copy remained unverified. Now program
seems exactly what it should be. (Dennis is creator of our three I/O
Packages, Items 40, 41, and 42 on Echelon Price List.)
By the way, AC makes dandy file MOVE, as opposed to COPY, program using
the trailing e option. Command ac b:=fn.ft /e<cr> copies fn.ft to B:
directory from current, then erases fn.ft from current after coping has
completed! Using AC and ALIAS, ZRDOS owners can create a mv function for
moving files, one having simple and easy to remember syntax.
Richard Conn, author of ZCPR3, has finished writing a tutorial on I/O
Packages. Fifty-page document shows how to modify your BIOS for efficient
input/output redirection. IOP concepts and design criteria receive detail
treatments. We publish as loose-leaf and offer for $9.95 plus shipping and
handling, is Item 84 on price list. On the other hand, tutorial is so
important we placed it (as file IO/P.LBR) on our nodes for downloading--take
it, but only if you want to learn things I/O.
Magazine Micro Cornucopia has commissioned busy Richard to write an in-
depth article on ZCPR3 and Z-System, piece scheduled to appear in Oct/Nov
issue, No. 26. Certainly, we have been frustrated in our struggle, in our
inability to explain satisfactorily what Z is all about. Everything we speak
and write seems to generate more questions than answers. Of course, your
interest is shown by all this, and we rejoice! Nonetheless, Richard currently
expends much energy on Micro C article hoping it fosters increased
understanding, fewer questions.
ZCPR3: The Manual and Term3 Status: Yes, manual is shipping, slowly.
Richard's book certainly answers many pent-up, so-far unanswered questions.
Term3 about to ship...another fortnight and it should be...documentation
taking longer than planned.
Software Musings: Zilog Z80 instruction set is so powerful that it's a shame,
historically, Intel 8080 common-denominator code writing started and has gone
on for so long. Now with HD64180 high-integration microprocessor chip
availability, we start to forget 8080 and take full advantage of Z80 (and
National NSC800) hardware architecture, especially since Zas relocating macro
assembler is perfected (and is only $69.00). Zenith and Viasyn (CompruPro)
curse day they chose Intel 8085 (similar to 8080) as co-processor, instead of
Z80 or NSC800, in their S-100 bus computers.
The RISC (reduced instruction set computer) concept, fostered by Prof.
David Patterson and his University of California at Berkeley (CAL) students
and getting coverage by trade press, means little to us here at EI. We use
existing hardware power to simplify software and increase computer through-
put. Others play their games to break hardware market strangle-holds created
by Intel, IBM, et al; we won't!
Long live instructions DJNZ, INC, DNC, INI, INIR, EX, EXX, ADD, ADC,
LDIR, SET, RES, SBC, SUB, JR, and extremely versatile LD. And HD64180's MLT,
IN0, OUT0, OTIMR, TST should prove of great value for compact, fast code
production. Instructions LD (HL),C or LD C,(HL) require only one byte as
object code. Load (copy) the contents of memory pointed to (addressed) by
register-pair HL into C register, all in one byte! Many useful one-byte
instructions exist; two and three-byte ones usually complete our needs for
fast-code writing. Seldom do we use four-byte op-codes. Oi ghlge, two-byte
op-codes are required for typical programs, giving 6mHz HD64180 (or 8mHz Z80)
through-put of one_MIPS (million instructions per second)! Compare with
through-put (and with hardware/software costs) of 16/32-bit Intel processors!
Now that we have your full attention, consider: HD64180 double-precision
multiply bench mark reported in Z-News 107, pg 3, was obtained using short
(54-byte) assembly language subroutine. Listing comes from a yet-to-be-
released Hitachi application note. Interesting code works the way we multiply
with pencil and paper:
; 16-bit unsigned multiply with 32-bit result subroutine
MULTX: LD DE,(MEM1) ;16-bit unsigned arguments previously
LD BC,(MEM2) ; stored at locations 'mem1' and 'mem2'
MLTX0: LD H,C ;use lower order byte of
LD L,E ; of both words for 1st mult
MLT HL ;16-bit product stored
LD (RESULT),HL ; in 'result' location
LD L,H
LD H,0
LD A,B ;save
LD B,D
MLT BC ;diagonal multiply
ADD HL,BC
LD B,A ;restore value
LD C,E
MLT BC ;diagonal multiply
ADD HL,BC
LD (RESULT+1),HL ;interim product stored
LD L,H ;ready to shift second line
LD H,0 ; left then add to first
RL H ;rotate left through carry
LD E,A ;original b-reg value into e-reg
MLT DE ;multiply
ADD HL,DE
LD (RESULT+2),HL ;final 32-bit product available
RET ;return to caller
MEM1: DS 2 ;uninitialized area starts here
MEM2: DS 2
RESULT: DS 4 ;32-bit product (low-byte first)
Twelve bytes are removed if application program places data in BC and DE
register pairs before entry to subroutine (call to MLTX0, eliminate MEM1 and 2
references). Execution time: 37.1 usec (microseconds) with 6.144 mHz clock
(0.163 usec period), 42 op-code/operand fetches, 3 clock cycles per fetch, 110
machine cycles and 185 states. Recall, Z80 processor took 302 usec (8 times
longer than HD64180) to double-precision multiply, lacking MLT instruction.
Ready your order for SB180; call The Micromint at 800/635-3355.
Incidentally, stand-alone BBS package (see Z-News 206 and 207), using SB180
and COMM180 (with MOSART and SCSI hard disk interface), has been given name of
TurnKey Bulletin Board System, TKBBS. And glory-be, there's been no price
increase! Full disclosure in upcoming communications issue of BYTE magazine.
Using ZAS: Universal assemble-link-load is major Zas quality, as well as
convenience and speed. Here's a few general rules to follow when assembling
an already-written source listing: 1) convert ASM, MAC, and LIB files that
use Intel 8080 mnemonics to Zilog with supplied Zcon converter and translator.
2) Make sure, by scanning source code with your editor, pseudo-ops don't start
in column one but in operation/operand columns, usually column 2 through 32.
Column one is reserved for labels, except leading line comments may occupy
this column. Normally, pseudo-ops start in column 9, the first tab stop. 3)
Comments start with a ";" (semicolon) and not with "*" (asterisk); neither ASM
nor M80 permit other than semicolon. (Unexpectedly, Patrick O'Connell, author
of Zas, made present version of Zcon convert leading *'s to ;'s. Thank you,
Patrick!) Errors flagged by Zcon during conversion should be fixed before
assembling with Zas.
Investigate errors produced during assembly, then fix. First error
usually causes many subsequent errors, so fix first then see what remains to
be done, if any thing. Always fix next first error of previous assembly.
Typically, changes in source statement form make for error-free assembly.
For example, listing pseudo-ops like $-MACRO and $+MACRO should be changed to
should be "commented out" (see Z-News 106, pg 1, and 205, pg 3). Of course,
all new programs should be written using Zas User's Manual as absolute guide.
If ZAS doesn't perform as the manual indicates, fill out EI "Software Update
Form" explaining trouble and return to Echelon. Moreover, these fill-in-the-
blank forms should be used for program improvement suggestions, for any EI
product. We value your advice!
Amateur Z User's Corner: Above Zas discussions suggests a quick-and-dirty
alias to assemble converted-to-Zilog files (using Zcon) and link/load to
executable COM files:
No harm comes to file being linked if routines from invoked libraries are not
needed. Fast Zlink is intelligent enough to work quickly under such
conditions.
Z-Node Activity: Rea Williams, Z-Node 10, installed a 2400 bps modem and now
uses Z-Msg; try him by calling 714/855-0672. Also, Rea ordered a Micromint
SB180 single board computer and plans to quickly have it up as his node after
arrival in August.
Though not a Z-Node, Norm Feder is a ZCPR3 enthusiast. His BBS--Lands
End RCP/M--is in Sidney, British Columbia, Canada; dialing 604/656-9115 gets
his 300/1200 bps modem. Give our Great Northwestern neighbor a call for a
change of pace!
Oh, Happy Day! Z-Node Central up with 2400 bps communication capability,
starting today. David McCord, Sysop, obtained US Robotics Courier modem to
reduce your online time, your monthly telephone bill! Oh, Happy Day!
Silicon Valley (and other hi-tech regions) Brief: Ups and downs, peaks and
valleys, chills and fever (see Newsletters 007, pg 5, and 009, pg 7). Many
Silicon Valley companies (principally their management) appear suffering from
lack of discipline, knowledge, and understanding. Such suffering usually is
caused by greed (we, human beings, are yet perfected), aided substantially by
short-sighted mental conditioning, lack of significant education
(indoctrination, yes). Who knows where we've come from, where we're going?
Lacking knowledge, we take what comes.
Technology is no substitute for learning; yet, we seek push-bottom,
instant response and gratification! Life is to be lived--physical, mental,
emotional life--and from living, higher levels of understanding come, feelings
of satisfaction and fulfillment obtained. Those who acquire power without
regard for pain caused to others in the process produce exactly what they sow:
hostility and anguish! Sleep occurs not only at night for these power-at-any-
price holders but during the day. Still, it's during the day consciously
directed thoughts and locomotion are needed; anxious, subconscious energy
shouldn't control then. Wake-up America, Sun is high in sky! Breakfast,
brunch on lush strawberries and white Zinfandel--enter realms of enchantment
naturally! See you down the lines...
Echelon, Inc.
101 First Street
Los Altos, CA 94022
Telephone: 415/948-3820
Z-Node Central: 415/489-9005
Z-News 208 is Copyright 1985 Echelon, Inc. All Rights Reserved. Permission
to reprint, wholly or partially, automatically granted if source credit is
given to Echelon.
