mel@houxm.UUCP (08/08/83)
I have been using my Rainbow 100 daily since December and would like to pass
on a few tips and comments. (Very long article, sorry.)
I use YAM for terminal emulation and file up/down loading. I converted the
BDS C YAM (Yet Another MODEM program) from Chuck Forsberg's RBBS
[(503)621-3193 1200/300 baud] to Computer Innovations C86 since the Z80 side
of the Rainbow has no access to the communications port. Unfortunately, YAM
doesn't fit into a 64K system (everything converted to the 8088 takes gobs of
memory). There is another MODEM-like program available: MODEM-RB.CMD that
probably will fit in 64K. It is available from the Thousand Oaks RBBS at
(805)492-5472 1200/300 baud. There is a MBOOT-RB.A86 file there also to
permit bootstrap from ASCII-only to full binary communications. YAM is MUCH
better (30+ pages of scroll-back, batch transfers, lower-case controls, etc.).
I have heard of another file transfer program: KERMIT available in University
circles, but haven't been able to wade through the TOPS-20'isms of it to find
out what it can do, or how it runs on the Rainbow.
I heard that the new Rainbows have a kludge to prevent non-DEC communications
programs from working (only those in on the secrets can bring up TERMINAL
READY to the modem). If this is so, please someone post the secret so DEC can
be short-stopped in this rip-off. It's bad enough that they force you to buy
their excessively expensive disks ($6.50 each) because of the secret
formatting required.
I use BDS C for programming. Fast compiling, bug free, useful library, a joy
to use (but not very much like Bell UNIX C). BDS C 1.5 does not work on the
Rainbow as it comes, you have to DDT in a RET into c.ccc at the location of
label "vkhack" to keep the "debugger" from using the RST instruction and
messing up the Z80-8088 communications. This is very easy (if you have a DDT
manual, DEC doesn't supply one), just refer to the first two pages of the
ccc.asm listing. Several other really neat CP/M programs fail for the same
reason (they just deep-end right at the beginning). Usually, you can pull the
same DDT trick, as few really use the interrupts.
Another DEC'ism keeps the Rainbow from running common CP/M programs. CP/M
2.2 specifies that on return from a BDOS call that A and L will contain the
returned information. On the Rainbow, only A contains the value; L is garbage.
The usual symptom of this is that you have to type characters at random to
permit the CP/M program to run (i.e. the poll of the keyboard looking at L
always sees a character waiting, even when there isn't; and the program hangs
trying to read the character that isn't there).
Rainbow MBASIC doesn't like multiple statements on a line (: convention), thus
won't run most common BASIC programs. Rainbow MULTIPLAN has no way to specify
a format for a whole column unless the whole column has content; a royal pain
in the ....; makes MULTIPLAN useless for such simple things as ledgers and
checkbook keeping. Also, MULTIPLAN doesn't keep its names from one form to
another, making it very tedious to setup monthly things that feed a yearly
report (the one big sales pitch "feature" of the thing). I don't have any
other DEC software for the Rainbow, and believe me -- won't.
I use MINCE for editing, a joy of a program: lightning fast, flexible, well
thought out, super documentation (even source code for most things you might
want to play with), and good primer and tutorials. The Rainbow keyboard takes
all the pleasure away, however. MINCE uses the ESC key a lot, and that's way
up there in never-never land. Also, MINCE uses Ctrl- keys for cursor motion,
deleting, skipping lines, etc.; and on the Rainbow those keys don't auto-repeat
(unfortunately, the <<<<<<<<< key where the SHIFT key should be, does). These
same mis-features burden the user of the Rainbow as a terminal. TIP: you can
pull off the CAPS LOCK and COMPOSE CHARACTER keys by carefully prying in on
both sides with paperclips. Throw those keys away - they are too easy to hit
by mistake. For the few times you might want all caps, just poke in the slot
with a paperclip. Now if I could only find a way to saw off the rightmost 8"
of this superfluosity.
It's not shown in the manuals, but the little inspection door on the bottom
right of the display is really a push button to control a spike that shoots
out of a hole in the bottom. Makes a neat way to prop up the display to keep
the reflections out of your eyes. Much better than the big book I used for 5
months.
By all means get the floor stand. Don't attempt to use the Rainbow as a desk
unit. The fan will drive you bonkers. It doesn't sound loud at first, but as
time goes on it starts sounding like an airport. Also, the air whizzes out
the left end, cold and mean. The disk units also have a nasty raspy noise
best kept under cover. The disks catch on a little tab of metal as you pull
them out, so be careful. The little tab bends, too, and that is what senses
the write protect tape (just exactly backwards from ALL other write-protects;
you put ON the tape to write protect), and when bent occasionally tells lies
and prevents writing on the disk. Get the DEC maintenance ("protection")
contract, since it would otherwise cost big bucks to get the tab bent back.
CP/M allocates the disks in units of 2K, so the programs LU, SQ, and USQ are
musts (get them from your friendly local RBBS).
What is my overall impression? I am very sorry I bought the unit. It has
lots of good ideas and advertising, but none of them are executed well. The
keyboard is "ergonometrically" designed for an octopus, not a human. The 8088
could run IBM PC programs, except that IBM disks can't be read and none of the
IBM ROM resident code is supplied - so none can. The Z80 could run regular
CP/M programs, except that no standard format CP/M disks can be read and the
CP/M supplied is non-standard - so few can. DEC supplies nothing in the way
of support (despite what they advertise). There are no manuals for most of
the standard software, not even the Digital Research boiler plate for CP/M.
There are no technical manuals at all (I got some pre-release stuff, mostly
useless). I had to hound DEC for months to get their expensive "protection"
contract, and I am still not sure they will fix the thing when it breaks.
There is precious little in the way of expansion and growth. DEC promises
"sometime" to offer an already obsolete 5M harddisk. I have 128K memory, but
only 64K fits on the Z80, so scratch CP/M-Plus; and 128K or 256K is too little
for effective use of Concurrent-CP/M or the new MS-DOS versions and
UNIX-alikes. DEC doesn't supply the BIOS source or any utilities to make a
new system if you knew how, so you can't tailor ANYTHING for your own use.
All in all it is a botch of a product, and I hate it.
(The personal opinions of) Mel Haas , houxm!mel