Ethan's Retrocomputing Corner


PDP-8 Articles From classiccmp And pdp8-lovers Lists:

From: Tim Shoppa <shoppa@trailing-edge.com>
Organisation: Trailing Edge Technology
Subject: Re: hooking up 8" floppys to a peecee
Date: Tue, 02 Mar 1999 21:38:00 -0400
Reply-to: PDP8-Lovers@zach1.tiac.net

Aaron Nabil wrote:
> Is it practical to hook up an 8" floppy to a standard peecee floppy
> controller and read os-8 formatted disks?  I'm more interested in
> the writing the disk image out than the ability to inspect
> individual files.
> 
> Are there any notable programs for doing this?

John Wilson's already mentioned PUTR, and I can strongly
recommend it.  He's also mentioned some floppy controller chips
that are known to work with single density floppies - important
in your case.  I've had good success with controllers based
around the Goldstar Super I/O chips, as well as the on-board
floppy controllers on Adaptec 1542's (Intel 82077's).

A post to comp.os.cpm late last year by Amardeep S. Chana
enumerated these chips:


Will support single density / FM:

        NS PC87306 Super I/O
        SMC FDC37C65
        SMC FDC37C78
        Most SMC Super I/O chips

Will NOT support single density / FM:

        NS 8473
        NS PC87332* Super I/O
        NS PC97307* Super I/O
        WD FDC37C65
        Most (if not all) Intel parts
        Any Winbond part
        Any UMC part

Reportedly will do single density / FM but NOT verified:

        NS 8477
        Intel 82077AA
        Goldstar Super I/O

> Any notes on how to build the adapter cable necessary?

> From the comp.os.cpm FAQ:

Q14: Can I read my 8" disks with my PC?

A: (John Baker, Tom Sullivan)

   With a program called 22disk, and an adaptor board that you can
   make, you can read those disks on your PC. All it takes is
   rearranging some of the lines on the 34 pin cable, and wiring them
   to the 50 pin cable, and you're in business.

   The interface on 8" drives and 5 1/4" drives are essentially the
   same.  The 34 lines on a typical 5 1/4" controller are sufficient to
   control most 8" disk drives using soft-sectored disks.  Here, is a
   diagram for a basic conversion cable to allow connection of an 8"
   drive to an IBM-compatible, AT-style (high density) controller.

                                                      8" disk drive
   PC-AT style controller                       Based on Shugart SA-851

   Grnd. Sig.  Sig. Name                             Sig Name  Sig Grnd
     1     2   Double/High Density ->>
                                    >>- Write Current Switch/    2    1
                                   Active Read Compensation
                                   User Customizable I/O pins    4    3
                                    "         "       "    "     6    5
    33    34 **Ready ---------------<<------------ True Ready    8    7
                                    <<-------------#Two Sided   10    9
    33    34 **Disk Change ---------<<----------- Disk Change   12   11
    31    32   Side 1 Select ------->>-----------#Side Select   14   13
     3     4   In Use/Open --------->>---------------- In Use   16   15
    15    16  *Motor On ------------>>------------- Head Load   18   17
     7     8   Index ---------------<<----------------- Index   20   19
    33    34 **Ready ---------------<<----------------- Ready   22   21
                                    <<---------------##Sector   24   23
     9    10   Drive Select 0 ------>>-------- Drive Select 1   26   25
    11    12   Drive Select 1 ------>>-------- Drive Select 2   28   27
    13    14   Drive Select 2 ------>>-------- Drive Select 3   30   29
     5     6   Drive Select 3 ------>>-------- Drive Select 4   32   31
    17    18   Direction Select ---->>------ Direction Select   34   33
    19    20   Step ---------------->>------------------ Step   36   35
    21    22   Write Data ---------->>------------ Write Data   38   37
    23    24   Write Gate ---------->>------------ Write Gate   40   39
    25    26   Track 00 ------------<<-------------- Track 00   42   41
    27    28   Write Protect -------<<--------- Write Protect   44   43
    29    30   Read Data -----------<<------------- Read Data   46   45
                                    <<------##Separation Data   48   47
                                    <<-----##Separation Clock   50   49

   This diagram also works in the other direction--that is, to attach
   high-density 5 1/4" drives to an 8" controller.

   Notes:

   *  It seems to be a logical substitution since the vast majority of
       8" drives have continuously running spindles and instead of
       MOTOR ON require a HEAD LOAD signal.  Also, a controller sends
       MOTOR ON before a DRIVE SELECT.
   **- Most 5 1/4" disk drives do not provide a READY signal but send a
       DISK CHANGE signal on line 34 of the interface.  An 8" drive has
       provisions for both signals.  Likewise, most AT-style
       controllers expect a DISK CHANGE signal on line 34, so lines 33
       and 34 should be connected to lines 11 and 12 of the 8" disk
       connector.  Also, some 8" drives provide a TRUE_READY signal
       which is more useful than the standard READY.

   # - Unused on single sided drives (SA-800/801).

   ##- Used only on hard-sector configured drives (SA-801/851).

   Some 5 1/4" disk drives have the option of providing _either_ DISK
   CHANGE _or_ READY on line 34 (in particular, the TEAC FD55R
   series).  Some 8" disk controllers do not care about the DISK CHANGE
   signal, but must have the READY signal.  If you are attaching a
   high-density 5 1/4" drive to an 8" controller, you may get away with
   making the drive always ready by shorting lines 21 and 22, but this
   may cause a few re-tries when switching sides.  If your drive offers
   a READY signal that your controller can deal with, by all means use
   it.

   The MOTOR ON/HEADLOAD dilemma may also have an alternate solution if
   you are connecting 5 1/4" drives to an 8" controller.  Some 5 1/4"
   drives permit motor turn-on by means other than the MOTOR ON
   signal.  For example, the TEAC FD55R series of drives may be
   configured to turn the motor on based on the state of the IN USE
   light.  The IN USE light can, in turn, be set to turn on only on
   drive select.  Thus selecting the drive automatically turns on the
   motor and neither a MOTOR ON or IN USE signal need be present.

   Another way to handle 8 inch drives on a PC is with a Microsolutions
   Compaticard IV, if you can find one. (MicroSolutions no longer
   offers this product.) It has the necessary software support to
   properly handle 8 inch drives, and in both SSSD and DSDD.  This
   controller can be set up as both a primary controller, or as a
   secondary. It can support 4 drives, of any type, including 2.8 meg.
   It supports two MSDOS 8 inch formats, SSSD (about 250k) and DSDD
   (1.2 meg). It works perfectly with 22disk, and can read and write
   almost any 8 inch CP/M format.

-- 
 Tim Shoppa                        Email: shoppa@trailing-edge.com
 Trailing Edge Technology          WWW:   http://www.trailing-edge.com/
 7328 Bradley Blvd                 Voice: 301-767-5917
 Bethesda, MD, USA 20817           Fax:   301-767-5927

From: David Gesswein <djg@drs-esg.com>
Subject: Re: Uploading files to PDP8/OS8
Date: Thu, 25 Mar 1999 7:33:22 EST
Reply-to: PDP8-Lovers@zach1.tiac.net

> Hello,
> I'm wondering if anyone out there knows of a reliable way to upload
> a text file from a PC running DOS to a PDP-8 running a limited
> load of OS/8.
 
I was trying to help somebody else do this to restore their system, I
have a program for the PC which will wait for the character to be
echoed so it doesn't overrun. This isn't reliable yet. I also have 
programs to dump and restore RK05 images between PC and PDP8 so you can 
use one of the emulators to add stuff which is the method I use.  I also 
have a version of kermit modified to use the console port.

The dump and restore programs are on http://highgate.comm.sfu.ca/pdp8,
the others I can email if you want.

If you found a better way can you let me know.

David Gesswein

From: Aaron Nabil <nabil@spiritone.com>
Subject: Re: Uploading files to PDP8/OS8
Date: Thu, 25 Mar 1999 14:11:57 -0800 (PST)

David Gesswein writes...
> . . .
> What program did you run on the PDP8 side?  I didn't find any ones with the
> standard OS8 distribution that knew about flow control so they all dropped
> characters on file download when they wrote a block out to disk.  They 
> also all terminated with a ^c so downloading binary images didn't work.
>
> Somebody posted a while ago about how to modify the serial card for hardware
> flow control off the reader run flag but I don't think any standard boards
> had that. 

That was me.  See http://www.spiritone.com/~nabil/pdp8/flow.txt

Subject: Re: Partial OS/8 Software Support Manual online
Organisation: D Bit, Troy, NY
From: wilson@dbit.com (John Wilson)
Date: 26 Mar 1999 00:05:25 -0500
Reply-to: PDP8-Lovers@zach1.tiac.net

In article <01J994VC60AA9OEN4J@cc.usu.edu>,
Roger Ivie  Having been blessed with a bit of a lull at the office this week, I've 
> typed in and HTMLized a chunk of the OS/8 Software Suport Manual. The
> parts I have so far are the introduction through Chapter 5. Web on over
> to http://cc.usu.edu/~ivie/ and click on "The OS/8 Software Support Manual".
>
> The copy I have is a copy of a copy and no one bothered to copy the back
> of the title page, so I don't know the date or version of this particular
> copy of the manual.
>
> I also don't know when I'll get to the appendices...

Ummm...  I hope you won't be upset at the duplication of effort, but
Lee Nichols already scanned in and edited the OS/8 SSM in 1996, it's at:

        http://www.dbit.com/pub/pdp8/doc/ssm.doc

including the appendices.

John Wilson
D Bit

From: roby@ida.org (Clyde Roby)
Subject: Re: Partial OS/8 Software Support Manual online
Date: Fri, 26 Mar 1999 09:22:01 -0500 (EST)
Reply-to: PDP8-Lovers@zach1.tiac.net

Roger,

Here's the URL of the document in pretty text form.
Hope it helps.

        ftp://tats.wizvax.net/pub/pdp8/doc/ssm.doc

Clyde Roby

Date: Thu, 1 Apr 1999 12:12:55 -0500 (EST)
From: allisonp@world.std.com
Subject: Re: Multi-User BASIC
Reply-to: classiccmp@u.washington.edu

> run?  If so, what version?  I currently have a fairly messed up, but
> bootable version of OS/8 V3Q
> on one RK05, but that's it, and no facilities as of yet to load a new
> operating
> system, but working on it.

Gee, there are only a handful of sites out there with complete
distributions for OS/8 (most versions).

 try http://www.dbit.com/

John Wilson has a lot there and also the old nickels site FTP as well.
if that isn't enough...

  http://www.highgate.comm.sfu.ca/pdp8

Allison

Date: Sat, 3 Apr 1999 19:17:31 -0800 (PST)
From: James Carpenter <jim_carpenter@yahoo.com>
Subject: [PDP8-Lovers] List addresses
Reply-to: PDP8-Lovers@onelist.com


Here are the new addresses for PDP8-Lovers:

pdp8-lovers-owner@onelist.com - Sends email to the list owner(s) 
pdp8-lovers-subscribe@onelist.co - Subscribe to the list
pdp8-lovers-unsubscribe@onelist.com - Unsubscribe from the list 
pdp8-lovers-normal@onelist.com - Switch your subscription to normal 
pdp8-lovers-digest@onelist.com - Switch your subscription to digest

pdp8-lovers@onelist.com is the list address. You must be subscribed to send
e-mail to the list!

I know some of you post from a few different addresses. You'll unfortunately 
have to e-mail me the addresses you'll be posting from. I'll then subscribe 
them to the list, configure them _not_ to receive list messages, and you'll 
then get a dumb message welcoming you to the list (again). If you send e-mail 
from an unsubscribed address you will get a bounce message back.

If you don't want to be on the list but want to post a message occasionally, 
just send the message to pdp8-lovers-owner@onelist.com and I'll post it for 
you.

Jim Carpenter
PDP8-Lovers moderator
pdp8-lovers-owner@onelist.com

Date: Sun, 4 Apr 1999 18:03:22 +0100 (BST)
From: ard@p850ug1.demon.co.uk (Tony Duell)
Subject: Re: bringing up an 8f...
Reply-to: classiccmp@u.washington.edu

> No I have the system up and running save for one bit that is stuck (when 
> displaying MD).  The display bit is stuck as test programs run verifying
> it's a front pannel problem.  It's bit 1 and only with the switch in the 
> MD position.

I've got the 8/e frontpanel prints here. From what I remember the 8/f is 
a little different.

The frontpanel display logic is mostly built from diode transmission 
gates - this circuit

  In---->|-----+-----|<------+--- Lamp driver
               |             |
  Sel-\/\/-----+             |
                             |
> From other gates-----------+
  for that lamp

The MD inputs have their own set of gates. I'd start by tracing from MD1 
(pin AL1) through the diodes to the appropriate 380 lamp driver 
(E26/6,7,2 on the 8/e). My guess is an open-circuit diode...

> 
> So far this is good success considering the heaviest test gear used is a 
> multimeter.  Also that I don't have a print set for 8E.

Oh, these old machines are quite easy to work on (famous last words...)

-tony

Date: Sun, 4 Apr 1999 19:20:31 -0400
From: allisonp@world.std.com (Allison J Parent)
Subject: Re: bringing up an 8f...
Reply-to: classiccmp@u.washington.edu

> I've got the 8/e frontpanel prints here. From what I remember the 8/f is 
> a little different.

The displays are leds (minor change around that part), otherwise it's 
identical to the 8e.

> The frontpanel display logic is mostly built from diode transmission 
> gates - this circuit
> 
>  In---->|-----+-----|<------+--- Lamp driver
>               |             |
>  Sel-\/\/-----+             |
>                             |
> >From other gates-----------+
>  for that lamp

Does not compute based on the chip part numbers.

> The MD inputs have their own set of gates. I'd start by tracing from MD1 
> (pin AL1) through the diodes to the appropriate 380 lamp driver 
> (E26/6,7,2 on the 8/e). My guess is an open-circuit diode...

Ther are very few diodes and the drivers appear to be 7404s with 74l54s
used as selectors.

Restate the problem... The display is the variable 12bit on off the 
rotary switch and only occures when MD is selected.  This suggests the 
data selector logic or it's particular source on the board as MD on the bus 
has the correct data.

> Oh, these old machines are quite easy to work on (famous last words...)

Generally the PDP-8 series is fairly straightforward.

Allison

Date: Mon, 05 Apr 1999 10:23:03 -0700
From: Chuck McManis <cmcmanis@mcmanis.com>
Subject: Re: bringing up an 8f...
Reply-to: classiccmp@u.washington.edu

At 05:40 AM 4/5/99 -0400, Allison J Parent wrote:
> The last 8e panel I worked with was also ttl.  there may have been two 
> versions (very likely).

Actually you can date '8s by their front panels ;-) The original PDP-8/E
panel used diodes and a separate lamp supply. At some point (between 1970
and 1972) it was re-designed to use TTL and at the same time the need for
the separate lamp supply was removed, later the lamp sockets were rewired
to accept LEDs (lamps burn out a lot), and then later still (about 1972+)
the LEDs were wired directly on to the panel. I believe, but have not had a
true digit confirm, that the 8/F was named such because the panel had
evolved to the point where it no longer looked like an "E". Clearly the
front panel graphics were redesigned a bit but not much else. The 8/M is
exactly the 8/F with a different decal plate and switch colors (the light
and dark hues are exactly reversed) [If you look at Megan's picture of the
'haul' you can see this in the 8/e and 8/f]

Anyway, if you've got a TTL front panel they are all pretty much the same.
The 8/e/f/m printset only describes this panel. 

--Chuck

Date: Thu, 8 Apr 1999 22:28:36 -0400
From: allisonp@world.std.com (Allison J Parent)
Subject: Re: bringing up an 8f...
Reply-to: classiccmp@u.washington.edu

Well folks,

The 8F is now up and basically healthy. The stuck bit was a bad 74L54
that had a stuck input.  Shame the replacement I have is a year older than 
the machine!
 
I ran one program that will execute on a DECMATE but the result is not 
visible! ;)

/       TEST PROGRAM FOR pdp-8f
/ inchworm  view with pannel switch set to Acc (8E/F/M)
/
0200            *0200                   / start address
0200    7200    START,  CLA             /CLEAR ACC
0201    1211            TAD     WORM    /PUT WORM CHARACTER IN ACC
0202    7004    MAIN,   RAL             / PUSH THE WORM LEFT
0203    7000    DELAY,  NOP
0204    7000            NOP             
0205    2212            ISZ     DELCNT  /DELAY 4096 (~20MS) INNER
0206    5203            JMP     DELAY
0207    5202            JMP     MAIN
0210    7402            HLT
0211    0007    WORM,   0017            / FOUR BIT LONG INCH WORM
0212    0000    DELCNT, 0000            / INSIDE LOOP COUNT
0213            $

Next step is to get the terminal interface in and try it and also verify
all of CORE as all I've checked is most of 00200, page 0 and random words.

Allison

Date: Sat, 10 Apr 1999 23:17:45 +0100 (BST)
From: ard@p850ug1.demon.co.uk (Tony Duell)
Subject: Re: 8/E PSU resolution
Reply-to: classiccmp@u.washington.edu
 
> Mine's set up pretty similar except for two differences...
> 
> At 03:35 PM 4/10/99 -0400, Allison J Parent wrote:
> > Here is the lineup from mine and the recommended board layout.
> >
> > 54-09668 KC8FL   PDP-8/F Programmer's Console
> > M8330   KK8E    Timing board, replaces M833
>   M8340   KE8-E     Extended arithmetic element decoder and step counter
>   M8341   KE8-K     Extended arithmetic element multiplexers and timing
> > M8310   KK8E    Major register control
> > M8300   KK8E    Major registers

Those boards have to be next to each other in that order for the top 
connectors (H851?) to fit
 
> And on mine this board:
> 
> > M837    MC8E    Extended Memory and Time Share Control
> 

It doesn't matter, but it's more common to stick that with the CPU boards 
at the front of the machine.

> Is right in front of the RFI shield (and core stack) Sort of "all
> components of the memory subsystem together" kind of thing :-)

Here's my configuration : 
KC8E frontpanel
M8330 clock/timing
M8340 EAE
M8341 EAE
M8310 Major registers control
M8300 Major Registers
M837 MMU/timeshare
M868 DECtape controller
M863 12 bit I/O
M8655 console port with UART (RS232)
Spare slot
M882 line clock
M7104 RK8e RK05 controller
M7105 RK8e
M7106 RK8e
Spare slot
M8357 RX8e RX01 floppy interface
M8342 printer interface
M847 diode matrix boot ROM
---Second backplane---
M840 PC8e PC04 interface
2 spare slots
M849 RFI shield
3 sets of : G111, H212, G333 ? 8K core memory
M8320 Bus loads

-tony

Date: Thu, 06 May 1999 15:38:46 -0700
From: Kevin McQuiggin <mcquiggi@sfu.ca>
Subject: Re: [PDP8-Lovers] Seeking: EDUSystem software...
Reply-to: PDP8-Lovers@onelist.com

Hi Jim:

See http://highgate.comm.sfu.ca/pdp8/dectapes for a some paper tape images,
these are DECtapes. Each file is a disk image. The "list" and "dirs" files
list what each file contains.

Good luck,

Kevin

At 11:25 AM 06/05/99 -0700, you wrote:
> From: James Willing <jimw@agora.rdrop.com>
>
>
> Ok, someone has this stuff filed in the closet somewhere...  B^}
>
> I'd (and some others around) like to find copies of one or more the
> various versions of the EDUSystem (timeshared BASIC) series of software
> for the PDP-8.
>
> (does anyone besides me see a VCF III demo coming on?)  B^}
>
> The one source (pun intended) that I've located on the 'net for
> EDUSystem-25 is partially corrupted (in the math/init section), and so is
> of marginal use...
>
> Does someone have archives of this stuff hiding on some
> disk/tape/paper/etc. somewhere?
>
> Thanks!
> -jim
> ---
> jimw@computergarage.org
> The Computer Garage - http://www.computergarage.org
> Computer Garage Fax - (503) 646-0174

From: "Vines, Robert F" <VinesRF@navair.navy.mil>
To: "'pdp8-lovers'" <pdp8-lovers@onelist.com>
Date: Thu, 5 Aug 1999 13:24:40 -0400 
Subject: [PDP8-Lovers] Device Code List Needed & Some Device Code & IOT Questions

Does anyone have a list of device codes (for a PDP-8/A if that matters)?

I am disassembling bits and pieces of a test program which uses device codes
that I can't find in my (limited) documentation.  One example of the
(incomplete) original documentation is:

================================================================

                /8-11-75
                /MUXRD
                /ROUTINE TO READ THE DIGITAL MULTIPLEXER
                /ENTER WITH MUX. ADDRESS IN AC
                /EXIT WITH INPUT WORD IN AC
1272    0000    MUXRD,  0
1273    6300                    LMUXAD  /LOAD MUX. ADR. REG.
1274    7200                    CLA
1275    6572                    DBRD            /READ SELECTED WORD
1276    5672                    JMP I MUXRD     /EXIT
================================================================

I understand that "6xxy" instructions are IOT instructions, where "xx" is
the device code and "y" specifies the operation to be performed.

I have to admit that I don't *really* understand what a "digital
multiplexer" is and what it does.  Is the "6300" instruction (and its
comment) telling me that the multiplexer's device code is "30"?  Am I
correct in assuming that the last "0" tells device 30 (the multiplexer?) to
load its ADdRess REGister (? I think) with the contents of the accumulator,
which was previously loaded with the "address" to be read?  Would/could this
"address" possibly tell the multiplexer which of its "incoming" data lines
to read?


Table D1-38, page D1-16, in Digital's "introduction to programming" (3rd
edition, 1972), says that 65x2 is DBRD or "Read incoming data into the AC,
clear receive flag" for the DR8-E Interprocessor Buffer.

What does the "x" stand for in this DBRD instruction?

What is the "DR8-E Interprocessor Buffer" and where is it located in a
PDP-8(/A)?

-----

One portion of the documentation states:

================================================================
/UNIQUE I/O INSTRUCTIONS FOR THIS SYSTEM
LMUXAD=6300             /LOAD MULTIPLEXER ADDRESS
                        / (AC BITS 8-11)
LX2LS=6303              /LOAD X2 COUNTER WITH 12 LSB'S
LX2MS=6304              /LOAD X2 COUNTER WITH 4 MSB'S
                        / (AC BITS 8-11)
LVDSPY=6305             /LOAD VELOCITY DISPLAY REGISTER
LPDSPY=6306             /LOAD PITCH RATE DISPLAY REGISTER
LTDSPY=6307             /LOAD ELAPSED TIME DISPLAY REGISTER
LCPW1=6310              /LOAD CONTROL PANEL REGISTER WORD 1
LCPW2=6311              /LOAD CONPRNL PANEL REGISTER WORD 2
DBTD=6574               /LOAD 8A OUTPUT REGISTER
DBRD=6572               /READ 8A INPUT REGISTER
================================================================

Does this mean that a programmer can assign certain device codes as he/she
sees fit?  If so, how do you do that?

Are there any "rules of thumb" that apply to the many different 6xxy "IOT"
instructions (such as listed in Appendix D1 in "introduction to
programming")?

Thanks,

Bob Vines

Date: Thu, 5 Aug 1999 14:47:17 -0500 (CDT)
From: "Douglas W. Jones" <jones@cs.uiowa.edu>
To: PDP8-Lovers@onelist.com
Subject: Re: [PDP8-Lovers] Device Code List Needed & Some Device Code & IOT Questions

When a device is documented as having device code 65x0, this typically
indicates that a switch or jumpers on the device can be used to set the
address to which it responds.  Each device typically has its own PC board
for the interface, plugged into the bus, and where the device code
contains an X, the device will have jumpering or a DIP switch that must
be set to match the software.  A few devices could be jumpered to respond
to any device code, but most had boards that fixed most of the addresses
while allowing only the least significant bits of the address to be set
by jumper.

For the old-line posibus and negibus PDP-8 systems, the least significant
3 bits of IOT instructions were seriously constrained.  For the 8/E and
the 8/A, the device hardware could do anything it wanted with the least
significant bits of the instruction, so if a device responds to IOT 635y,
the 3 bits of y go into a 3-input 8-output decoder, and the device designer
is free to do anything at all with the outputs of that decoder.

Standard DEC devices, particularly those from early in the OMNIBUS era,
tended to conform to constraints not too different from those of the older
posibus and negibus, but later, they began to get creative, so you couldn't
assume any standard meaning for the different values of y.

On the earlier posibus and negibus systems, the 3 bits of y were sent out
on 3 separate clock lines, the IOP lines, and they were sent in sequence,
100 before 010 before 001.  As a result, each device could do 3 consecutive
register transfers on each IOT, and the 3 bits usually determined which of
these 3 operations was to be done for that instruction.  IOT 6xx0 would
do none of them, while IOT 6xx7 would do all of them.

On the earlier busses, if you wanted to do freehand decoding of IOTs, you'd
have to catch the first 2 pulses in a 3-bit register and then, as the third
pulse arrives (or fails to arrive), take action appropriately.  This was
difficult, and so it was rare.  The goal of the old design was to minimize
the per-device logic, back when discrete transistors were the rule.

                                Doug Jones
                                jones@cs.uiowa.edu

Date: Mon, 26 Jul 99 07:42:54 PDT
From: "Bob Armstrong" <bob@poco-adagio.santa-clara.ca.us>
To: pdp8-lovers@onelist.com
Subject: [PDP8-Lovers] Can I use RL02s with OS/8 V3D?

  Is it possible to use RL02s (not RL01s) with OS8 V3D?  I've been looking
at this, and it seems to be a real mess.  The V3D DEVEXT kit supports RL01s
but not RL02s.  You could probably copy the RL02 drivers from the OS78 V4
kit and use those with V3D (at least I'm assuming you can - has anybody tried
it?), but you also need a format program.  RLFRMT from V3D only works on
RL01s, and for RL02s you need the FORMAT program from OS78.  Unfortunately
FORMAT can't be run with the "R" command - it requires CCL support.  So this
means I have to use the OS78 CCL on V3D which, although I haven't tried, I
suspect will lead to more headaches.  Is there a formatter program for RL02s
that works on V3D?  Am I forced to run OS78 V4 to get RL02 support?

  I've got an 8/A in the garage with a RL02/RL8A that's just dying to know :-)

Thanks,
Bob Armstrong
bob@poco-adagio.santa-clara.ca.us

Date: Sun, 18 Jul 1999 17:05:30 -0400 (EDT)
From:  David Gesswein <djg@drs-esg.com>
To:  PDP8-Lovers@onelist.com
Subject: [PDP8-Lovers] Online pdp8

I have finally gotten my online pdp8 project working well enough to announce.

Go to http://highgate.comm.sfu.ca/~djg/onlinepdp8.html and give it a try.

The site needs a lot of work, consider this a beta test so if you don't like
them wait until my next announcement.  From the site you can run a PDP8/E 
system with currently 2 RK05 (one down for maintenance), 1 TU56 dual DECtape, 
and a dual RX02 floppy drive.  More in the future.  The processor has the
EAE board set but it appears not to be operating correctly right now.

I also have a bunch of images for the drives, OS/8, ETOS (multi user virtual 
machine with OS/8), WPS/78, and COS.  I also have games on some of the
images.  I give pointers to a couple but I don't have the index done so 
you get to poke around.

I also have the start of documentation on the hardware and software, and 
operating instructions for the machines.  If you have no experience you
may have some difficulty.

I also have a not very good webcam so you can see that you are operating
a real machine.

To run the machine you need a browser with Java 1.1 or later and an
internet connection which allows connections to ports 8000, 10000, 10001.
It will not currently work with a proxy server.

Let me know what you think.  I know that a bunch of the links don't work
but email me with any errors or what is confusing or just how you like it.

David Gesswein
djg@drs-esg.com

Date: Sun, 18 Jul 1999 17:15:44 -0700 To: PDP8-Lovers@onelist.com From: Chuck McManis <cmcmanis@freegate.com> Subject: Re: [PDP8-Lovers] Online pdp8 Cool site Dave! I don't know what makes me more jealous, all that cool '8 gear or all the space you have around it to add more! --Chuck At 05:05 PM 7/18/99 -0400, you wrote: > From: David Gesswein <djg@drs-esg.com> > > I have finally gotten my online pdp8 project working well enough to announce. > > Go to http://highgate.comm.sfu.ca/~djg/onlinepdp8.html and give it a try.
Date: Tue, 6 Jul 99 19:35:26 PDT
From: "Bob Armstrong" 
To: pdp8-lovers@onelist.com
Subject: [PDP8-Lovers] What's the difference between the KM8AA and AB ??

  I've got a PDP-8/A (actually, it has a KK8/E CPU - M8310/8300/8258/8320 -
not the KK8/A, if that matters) that has a problem with the KM8A.  I've
actually got two M8317 KM8A boards - one is a YA revision and the other is
YB.  Can anybody tell me what the difference is ?  In particular, the YB
has three or four wire jumpers that aren't present on the YA - what do they
do ?

  The problem is that the YA board works, except for the bootstrap.  If I
hand toggle in a boot, then I can run OS/8 just fine.  The YB seems to be
"inert", at least as far as the EMA is concerned.  The LXA button on the
programmer's console doesn't do anything (i.e. the displayed memory field
never changes), and neither does a CIF or CDF instruction when I enter one
from the console and then single step it.  I'm assuming the YB is also
broken, but I thought I might be lucky and it's just the jumper setup or
something obvious.

Bob
bob@poco-adagio.santa-clara.ca.us

Date: 27 Apr 1999 00:59:47 -0000
From: Eric Smith <eric@brouhaha.com>
To: "Discussion re-collecting of classic computers" <classiccmp@u.washington.edu>
Subject: Re: DEC documentation RUMOR????

> I read a web page somewhere that indicated DEC put in the public domain
> all the documentation they no longer publish.
> 
> Is this true? Can anyone point me back to the original web page?

No, it's not true.  They have given permission to reproduce certain software
documentation, but they have not put *any* of it into the public domain.
There's a big difference.

Here's some info I found in John Wilson's FTP archive, excerpted from
the file
        ftp://ftp.dbit.com/pub/pdp8/doc/README
Note that it is restricted to Digtal's customers.  I wonder how lawyers
interpret that.


> From the January 1985 Software Documentation Products Directory (EJ-26361-78),
first page:

3. RIGHT TO COPY

   Beginning January 1, 1985, Digital customers are given a right to copy, at
   no charge, any Digital Archival Software Documentation Publication
   (excluding restricted or third party owned) that we no longer offer for
   sale.  However, the copyright is retained as the exclusive property of
   Digital Equipment Corporation.

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