lasner@WATSUN.CC.COLUMBIA.EDU (Charles Lasner) (10/16/90)
Hi!
I am Charles Lasner, affiliated with Columbia because of KERMIT. I
maintain KERMIT-12 for the DECmate and PDP-8. I am interested in
Rainbow and DECmate stuff, and I am always seeking Rainbow-oriented
programs that run on the DECmate.
My favorite DECmate editors are TECO for the -8 side, and SEDT for the
MS-DOS side. I use the Rainbow SEDT which runs just fine on the
DECmate, although it's funny that SEDT believes the DECmate to actually
BE a Rainbow (says PC 100). DED apparently also works here too. I
would be interested in compiling a list of those programs which run on
both DM and Rainbow. My DECmate is the following configuration:
Standard DECmate II with Rainbow-type box and power supply. PDP-8
motherboard with built-in support for two pairs RX50. One fits in the
box on the right. The second pair plugs into the motherboard and can
occupy the box center if no hard disk. There is a slot which supports
either 8" controller called RX78 (runs one or two RX01 or RX02s) or
hard disk controller for RD disks, etc. IF the RX78 is present (or
slot empty), then second RX50 and RX01/02s arfe all viable at once.
That's EIGHT floppies at once! I more usually have only the first
RX50, and the hard disk controller. The second RX50 can be run from an
external box regardless of whether the box is otherwise occupied; the
software seems to know of this (slightly) non-standard configuration.
If you have 8 floppies, the first RX50 are A: and B:, the second is C:
and D: and the RX01 (or 02) becomes E: and F: (and G: and H: if yhe
second RX01/02 exists).
My hard disk is an ST4096 Seagate which wastes the ninth head, so it's
as big as the Micropolis 1325 everybody else wants. DEC never
supported the use of the WSI pin as the high-order bit of head select,
so we all have 8 heads logically (at most). Well, 64 Megs formatted is
acceptable. I also have the graphics option board, which is based on
the NEC 7220 chip like the VT240,241 and RB. I don't have
documentation on how to program the Graphics board, but I am piecing
together info from various "sources" (more on this if you want). The
thing that makes this machine more like the RB is the auxiliary
processor slot where the APU (Z80 only) or XPU (8086 and Z80) goes.
Since this is an 8086, it is faster than the Rainbow, and since the
6120 does screen I/O, programs like generic KERMIT-MS run FAST on it,
unlike PC XTs which are REAL slow with BIOS calls versions of KERMIT,
etc. The fastest comm speed supported is 9600 baud, a restriction of
the support environment, but I am convinced it could do more if I could
get info about the 8BIOS code. My KERMIT-12 does 19,200 baud fromt he
"pure" -8 environment. I have the XPU board, which comes in 2 flavors:
a 256K board (not mine!) and a board that can have 1 meg on it that
ALWAYS comes half empty! The 512K is the only "officially" supported
larger board, but I am tempted to put sockets on the other half!
Remember, this is an 8086 board, not 8088, so it's 16-bit wide memory,
.5 or a whole meg, no other numbers possible. I don't know if the
released IO.SYS for DM MS-DOS (2.11 was only release) can do a meg. I
have been told that the high 16K of the 1 meg space is the comm area to
the Z80. There are NO roms except in the Z80 itself. The PDP-8 runs a
server program, and downloads Z80 code and starts it up along with the
BIOS in Z80 roms (16K worth). The Z80 runs CP/M-80 using RB format
disks and tells the -8 server to do all via the z80-PDP-8 interface.
To run MS-DOS, there is an interface between the Z80 and the 8086 as
well, so the Z80 runs the 8086 processor to get it up, so it requests
I/O service from the Z80 which in turns requests it from the -8! From
the 8086 point of view, the Z80 is doing "DMA" for it, since memory
fills without 8086 instructions. The PDP-8 program transfers the data
into/out of the Z80 to complete the service. All actual I/O is
indirectly done by the -8 via commands from the Z80, which is in turn
driven by the ram-resident DOS BIOS in the top portion of 8086 memory.
BIOS moves as necessary, and it's all soft. IF it can be made to
reloacte accordingly, DM MS-DOS will have MORE memory than the Victor
9000 or Rainbow (both max out at 896k).
The DM can't have an 8087. I have not tried a V30, but I assume that
works as well as the V20 in the RB. I need the 8 Meg version. Various
CPU MHZ versions tell me that my clock is 7.7 MHZ, but this is an 8086,
not 8088, so it's probably a little slower clock.
The graphics board can talk to the required VR-201 or to the VR241, or
both. DEC supplies a VT240/241 emulator that is just about totally
compatible. The differences seem to be software issues where the
emulation favors the VT-125 over the VT-240/241 where they diverge.
(very slight.) You can't have a color-only config due to other
requirements needing the VR-201. The standaard system is shipped with
the WPS keycap keyboard, which I use (blue, not red stripe). My
monitor is green (big deal!). The support for non-standard disks
revolves around a "clandestine" formating program (sound familiar?),
but I have a binary copy. The controller is "intelligent", and a PDP-8
program runs the entire machine called MASTER MENU. Operating systems
come up under MM as "applications" in the menu. We have quite a
collection here:
OS/278 (pure -8 code)
COS-310 (likewise)
P?S/8 (proprietary OS from ME)
WPS-8 (mostly -8; optional Z80 utilities as needed)
CP/M-80 (no CP/M-86 though)
MS-DOS
Bootable floppies for random purposes also exist and can be menu items
(diagnostics, etc.)
Hard disk utilities. This is a stand-alone feature of MM itself. We
can dump/restore disk volumes, compress, copy, delete, alocate, list,
mount, etc.
Several operating systems support inter-system formats, etc.
My KERMIT-12 is for OS/278 with no option boards.
CPM-80 KERMIT-80 runs under CP/M-80
MS-KERMIT runsunder MS-DOS.
WPS8 does DEC DX transmission.
A FEW questions:
a) Any info about a company that sold a mouse for DEC LK-201
keyboards. Went between the keyboard and the monitor; I think it
worked on RB, DM, PRO, even VT220/240/241?
b) Anything known about a DEC program called Overhead Express for
RB/DM?
c) aNYTHING available regarding the ZORK trilogy for RB/DM? My
understanding is that there was a CP/M-80 version for DM and RB on
RX50s. All I am really interested in at the moment is whether they are
the IDENTICAL game as the IBM-PC ZORK disks, or for that matter, if the
PC zork disks are identical to them selves (early vs late). My point
it that the PC ZORK games I have seen are significantly different from
the MIT MDL version which only runs on a PDP-10/20, or its slightly
bastardized -11/vax ripoff/downgrade. The parser is as "smart" as the
-10 version, but the game is different, more contrived, and in any case
different particulars. I am hoping that the DEC CP/M disks are older,
and perhaps closer to the "traditional" version (also the published
"map" will be accurate, too! Except for about 4-5 random typos, the
-11/vax version is faithful to the -10 original).
d) Anything regarding MS-DOS versions of the "faithful" version of
the original PDP-10 adventure. I understand there may be a "C" version
for at least PCs, but no-one got the -10 Fortran version up anywhere
else. It is unacceptable to use the -11 version or any of its
derivatives, since the"trivialize" the commands to accomodate inherent
weaknesses of the -11 RSX Fortran, etc. I don't care what language it
runs in, although Fortran would be preferable. Authenticity is my goal
here.
Any "political" contacts within/without DEC would be helpful; the
DECmate, like the Rainbow (perhaps more severely) suffers from withheld
documentation preventing us from fixing it. The motivations of all
parties are the same as the RB, meaning we users want to support it,
and DEC wouldn't let us, etc.
BTW, are you aware that their is a PD program to format RX50 format on
PC-AT called FDFORMAT. It can really format from unmagnetized media,
and requires no hardware changes/special features, just HD drives
normally on PC-AT, although some crappy drives like Mitsumi can't do it
just because of how bad they are. This program also makes 1.48 Meg
5-1/4 floppies and 1.72 Meg 3.5 " floppies too! PCs can support 410K
disks just like Rainbow. Yes, that's 410K, not 400K. IT seems that
most drives can actually read track 80 and 81 or 40 if a 48 tpi drive,
so FDFORMAT makes 40 track pc floppies become 41 tracks and also
double-sided so they get 82 total tracks of 10 sectors each. RB/DM
should also get 82 tracks, but the BIOS may not like it. In any case,
PCs should do 10 sectors, just like DM/RB. Makes the disks the same
size, more convenient that way. You don't have to be a Vaxmate to run
this one! It also supports head and side stagger, so throughput is
faster. This makes all machines benefit. The RB could do this, but I
think the RB formatter doesn't support specifying a stagger factor (aka
slide factor). BTW FDFORMAT is available in SOURCE FORM.
Please comment on any/all of the above and reply to:
lasner@watsun.cc.columbia.edu
thanx
cjl (lasner@watsun)lasner@cunixf.cc.columbia.edu (Charles Lasner) (10/30/90)
I thank others for posting my rambling article about DECmates, etc. Now that I can post to the net myself, (although from this other machine: cunixf ONLY) I will put my own stuff up restricted accordingly. I just want to mention now about RX50 disks and compatibility. I understand that the Rainbow can read/write PC disks somehow. On the DECmate, the hardware can do an automatic check for 48 TPI disks, but read-only. DECmate MS-DOS supports reading and chkdsking, etc. of PC one-side 160K/180K disks. It can also complain that the directory on the disk indicates it is two-sided. You have to copy the files to another more "native" disk to process the files, because many utilities, most notably CONVERT can't access them directly. No real problem, just use a COPY command. CONVERT makes RX50 CP/M disks or WPS disks. The Rainbow loves the CP/M or MS-DOS disks directly, but due to some stupidity, the VAXmate identifies DECmate MS-DOS disks incorrectly yet reads Rainbow disks ok because they look at some pragmatism on the disk, not the "right" way by media type. Only the DEcmate II has the MS-DOS option, but the II and III and III+ can do CP/M-80. Due to a hardware bug, the III+ can't read the PC Disks. I assume that the II and III both like Robin disks also (read-only), so the III+ loses on that score too. DEcmate II with all floppies can have 4 RX50 and 4 RX01/02 drives. In that configuration, CP/M likes the old 8" CP/M disks from the 8080 CP/M days. Any format that was IBM 3740 underneath CP/M should work. I can do this if someone wants (means I have to dismantle the machine and take out the hard disk controller. 2 floppies and hard disk or up to 8 floppies is all you get!). I can distribute generic KERMIT-80 this way to those people! If anyone wants rx50 stuff moved to Rx01/02 or vice versa, don't hesitate to ask me. KERMIT can transfer back to OS/8 or RT-11 RX01/02 floppies or even DECtapes or LINCtapes. (want paper-tape?) cjl (lasner@watsun.cc.columbia.edu)