Subject: FD-411 Floppy Disk System
From: [email-masked] (Ignatios Souvatzis)
To: [email-masked]
Date: Sun, 2 Aug 92 02:48:55 +0200

Date: Sun, 2 Aug 92 02:48:55 +0200
From: [email-masked] (Ignatios Souvatzis)
To: [email-masked]
Subject: FD-411 Floppy Disk System
Reply-To: [email-masked]
Return-Receipt-To: [email-masked]
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Hi,

I saved a 'FD-411 Double Density/Double Sided Floppy Disk System'
manufactured by Charles River Data Systems, Natick, Massachusetts,
from the trashcan.

What can I do with such  a beast? The  few remaining manuals deal only
with what to do when you have a PDP11 and the '11 controler for it. Is
it possible to connect it to a standard floppy controler of some sort?
Is there any PDP-8 Omnibus controler for it?

Date: Sun, 2 Aug 92 17:38:16 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: Module Number <-> Option Name (Omnibus)

Date: Sun, 2 Aug 92 17:38:16 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: Module Number <-> Option Name (Omnibus)

The following is an attempt at a fairly exhaustive list of OMNIBUS boards
that are known to have existed.  Any and all help I can get in fixing this
list would be useful, particularly, I would like to complete and correct
the mappings from board numbers to option names and their meanings.  Please,
if you have a correction, state your source (do you have the board?  This
tells us the thing really got made, unlike the VA8E character generator,
which is in my handbook but may never have been made).

				Doug Jones
				[email-masked]

This list is gleaned from many sources I have scrounged together:

  B -- Board number seen on an omnibus board.
	Rarely, boards will have useful meanings etched on them.
  M -- Option name and meaning from PDP-8/E,F,M Maintenance Manual.
	Sometimes, the manual also gives the board number.
  H -- Option name and meaning from the Small Computer Handbook (1971).
	Rarely, the handbook also gives the board number.
  P -- Board number and option name from DEC Option Power Requirements
	Engineering Spec dated 1/20/72, drawing number PDP8E-0-11.

the mapping from Options to Module numbers in 
NUMBER	OPTION	MEANING (SOURCE)

54-9057	KC8EA	PDP-8/E Programmer's Console (M,B)
54-9668	KC8FL	PDP-8/F Programmer's Console (M)
	KC8ML	PDP-8/M Front Panel (M)
A231	AD8EA	Analog to Digital Converter (P,H) 
A232	AH8EA	(P)
A841	AD8EA	Analog to Digital Converter (P,H)
G111
G104	MM8E	Memory sense/inhibit (P,M)
G105	MP8E	Memory sense/inhibit (Parity) (P,M)
G227	MM8E	Memory X/Y drivers (P,M)
G227	MP8E	Memory X/Y drivers (P)
G619	MM8E	Memory stack (M)
H220	MM8E	Memory stack (P,M)
H220	MP8E	Memory stack (P)
M512	DK8ED	(P)
M518	DK8EP	Programmable Real Time Clock (P,H)
M8300	KK8E	Major registers (B,P,M)
M8310	KK8E	Major register control (B,P,M)
M8320	KK8E	Bus loads (B,P,M)
M8321	TM8E	Magtape output control module (M)
M8322	TM8E	Magtape control and data break module (M)
M8323	TM8E	Magtape transport status and control module (M)
M8327	TM8E	Magtape register module (M)
M8330	KK8E	Timing board (B,P,M)
M8336	VT8E	Video Display Clock and Frequency Divider (M)
M8337	VT8E	Video Display Line Buffer Module (M)
M8340	KE8E	Extended arithmetic element (P,M)
M8341	KE8E	Extended arithmetic element (P,M)
M8350	KA8E	External positive I/O bus interface (B,P,M)
M8357	RX8E	RX8E Omnibus Interface (RX01) (B)
M8360	KD8E	Data Break Interface (P,M)
M837	MC8E	Extended Memory and Time Share Control (B,P)
M837	KM8E	Extended Memory and Time Share Control (H)
M839	DP8EA	Synchronous Modem (P,M,H)
	DP8EB	Synchronous Modem (Bell series 300 modem) (H)
M840	PC8E	High speed paper tape reader/punch interface (P,M)
M841	LE8XX	Line Printer Control (P)
M842	XY8E	X/Y Plotter Control (P,M,H)
M847	MI8E	Hardware Bootstrap Loader (P)
M848	KP8E	Power fail and auto-restart (B,P,M,H)
M849	KK8E	RFI shield (B,M)
M860	DK8ED	(P)
M860	DK8EP	Programmable Real Time Clock (P,H)
M863	DR8E	(P)
	DR8EA	12 Channel Buffered Digital I/O (H)
M866	DP8EA	Synchronous Modem (Bell series 200 modem) (P,M,H)
	DP8EB	Synchronous Modem (Bell series 300 modem) (H)
	DP8EP	Parity generator checker for modem use (H)
M869	VC8E	(P)
M865		Console Teletype Control (B)
M8650	KL8E	Asynchronous Data Control (B,P,M,H)
M8655		Terminal Control (B)
M868	TD8E	DECtape Control (P,M)
M882	DK8EA	Real Time Clock (Line Frequency) (P,H)
	DK8EC	Real Time Clock (Crystal) (H)
M884	KG8E	Parity Generator Detector (P)
M885	VC8E	(P)

Date: Mon, 3 Aug 92 08:07:41 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: Drawings

Date: Mon, 3 Aug 92 08:07:41 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: Drawings

Does anyone have the engineering drawings of the PDP-8/F front panel and
power supply?  I'm trying to accumulate a fairly complete documentation
set for my PDP-8 machines, and I'm missing these.

					Doug Jones
					[email-masked]

To: [email-masked]
Cc: [email-masked]
Subject: Equipment
Reply-To: [email-masked]
Date: Tue, 04 Aug 92 06:30:48 PDT
From: Val Fucich <[email-masked]>

To: [email-masked]
Cc: [email-masked]
Subject: Equipment
Reply-To: [email-masked]
Date: Tue, 04 Aug 92 06:30:48 PDT
From: Val Fucich <[email-masked]>

For those people that live in the Los Angles area. I have some
PDP-8 Equipment that I need to get rid of.
Val.

To: "Douglas W. Jones" <[email-masked]>
Cc: [email-masked], [email-masked]
Subject: Re: Drawings 
Date: Tue, 04 Aug 92 09:00:32 -0700
From: "Bob Kibrick -- [email-masked]" <[email-masked]>

To: "Douglas W. Jones" <[email-masked]>
Cc: [email-masked], [email-masked]
Subject: Re: Drawings 
In-Reply-To: Your message of "Mon, 03 Aug 92 08:07:41 CDT."
             <[email-masked]> 
Date: Tue, 04 Aug 92 09:00:32 -0700
From: "Bob Kibrick -- [email-masked]" <[email-masked]>

 >Does anyone have the engineering drawings of the PDP-8/F front panel and
 >power supply?  I'm trying to accumulate a fairly complete documentation
 >set for my PDP-8 machines, and I'm missing these.
 >
 >                                      Doug Jones
 >                                      [email-masked]

I have engineering drawings for the PDP-8/I, but not an 8/F.  In fact, I have
several complete PDP-8/I systems with EAE and DECtape that are being surplused
and which are looking for a good home.  Also, a small stock of DECtapes with
miscellaneous OS/8, DECUS, and FOCAL software, as well as DEC publications
such as Introduction to Programming and the OS/8 Handbook.  I also have the
complete set of DEC's PDP-8/I hardware diagnostics and associated
documentation.

Some of this stuff is in storage at the Lick Observatory facilities on the
UC Santa Cruz campus.  The remainder is in storage at our observing
facilities on Mt. Hamilton, which is about 20 miles SE of San Jose, California.

Bob Kibrick
Lick Observatory
Natural Sciences 2
University of California
Santa Cruz, CA 95064

[email-masked]

Date: Tue, 4 Aug 92 17:47:13 MET DST
From: Johnny Billquist <[email-masked]>
Reply-To: [email-masked]
To: [email-masked]
Cc: [email-masked], [email-masked]
Subject: Re: Equipment

Date: Tue, 4 Aug 92 17:47:13 MET DST
From: Johnny Billquist <[email-masked]>
Reply-To: [email-masked]
To: [email-masked]
Cc: [email-masked], [email-masked]
Subject: Re: Equipment
In-Reply-To: Your message of Tue, 04 Aug 92 06:30:48 PDT

>For those people that live in the Los Angles area. I have some
>PDP-8 Equipment that I need to get rid of.

Hi, Val. On another subject, since I don't live near LA.
I haven't heard anything from Wally. I think I remember that
you said ha had regained internet access. If so, could you
give me his email address? Or, drop him a note saying hi from me.
I'd like to hear from him.

	Johnny

To: [email-masked]
Cc: [email-masked], [email-masked]
Subject: Re: Equipment 
Date: Tue, 04 Aug 92 09:08:28 -0700
From: [email-masked]

To: [email-masked]
Cc: [email-masked], [email-masked]
Subject: Re: Equipment 
In-Reply-To: Your message of "Tue, 04 Aug 92 06:30:48 PDT."
             <[email-masked]> 
Date: Tue, 04 Aug 92 09:08:28 -0700
From: [email-masked]

Is west coast LA enough?
What do you have?

Paul Pierce

From @mitvma.mit.edu:[email-masked] Tue Aug 11 20:53:27 1992
Date: Tue, 11 Aug 1992 19:43 CST
From: ALEXANDRE KHALIL <[email-masked]>
Subject: non-Latin characters on the Net
To: [email-masked]

  Hello

  Is there a way to use non-Latin character sets on the network ?

  I would be interested in finding/hacking into an editor/mailer/list manager
that would allow redefinable characters to be handled properly on a graphics
terminal.

  Any clues??

Alex Khalil
U. of Houston-Downtown

Date: Thu, 20 Aug 92 04:10:48 CDT
From: "Andrew Luebker" <[email-masked]>
To: [email-masked], [email-masked]
Subject: fan-fold fossils

Date: Thu, 20 Aug 92 04:10:48 CDT
From: "Andrew Luebker" <[email-masked]>
To: [email-masked], [email-masked]
Subject: fan-fold fossils

Twice now, I have dragged this box away from the dumpster, thinking
it might be of some value to PDP archeologists.  It contains 14 cartons
of blank, unused gray DEC fan-fold paper tape.  Is this a museum item,
or are people still punching away long tickertapes?

  -Andrew Luebker-  [email-masked]

Date: Thu, 20 Aug 92 09:29:47 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: Revised OMNIBUS board list

Date: Thu, 20 Aug 92 09:29:47 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: Revised OMNIBUS board list

The following is an attempt at a fairly exhaustive list of OMNIBUS boards
that are known to have existed.  Any and all help I can get in fixing this
list would be useful, particularly, I would like to complete and correct
the mappings from board numbers to option names and their meanings, and in
cases where multiple suffixes existed, I would like to figure out the
differences.

This list is gleaned from many sources:

  B -- Board number seen on an omnibus board.
	Rarely, boards will have useful meanings etched on them.
  M -- Option name and meaning from PDP-8/E,F,M Maintenance Manual.
	Sometimes, the manual also gives the board number.
  H -- Option name and meaning from the Small Computer Handbook (1971).
	Rarely, the handbook also gives the board number.
  P -- Board number and option name from DEC Option Power Requirements
	Engineering Spec dated 1/20/72, drawing number PDP8E-0-11.
  G -- From Meg Geddes' memory.
  L -- From Charles Lasner's memory.
  F -- From Federated Consultant's July 1992 sale price list.

the mapping from Options to Module numbers in 
NUMBER	OPTION	MEANING (SOURCE)

54-9057	KC8EA	PDP-8/E Programmer's Console (M,B)
54-9668	KC8FL	PDP-8/F Programmer's Console (M)
54-9668	KC8ML	PDP-8/M Programmer's Console (M,L,F)
	KC8AA	PDP-8/A Programmer's Console (G)
A231	AD8EA	Analog to Digital Converter (P,H) 
A231	AD8E	Analog to Digital Converter (F) 
A232	AH8EA	Multiplexor for AD8EA (P)
A841	AD8EA	Analog to Digital Converter (P,H)
G111	MM8EJ	8K Memory sense/inhibit (L,B)
G111C	MM8EJ	8K Memory sense/inhibit (L,B)
G104	MM8E	4K Memory sense/inhibit (P,M)
G104C	MM8E	4K Memory sense/inhibit (B)
G105	MP8E	Memory sense/inhibit (Parity only) (L,P,M)
G227	MM8E	Memory X/Y drivers (P,M)
G227C	MM8E	Memory X/Y drivers (P,M)
G227	MP8E	Memory X/Y drivers (P)
G233E	MM8EJ	8K Memory X/Y drivers (B)
G619	MM8E	Memory stack (M)
G619A	MM8E	Memory stack (B,M)
G649	MM8AA	PDP8A 8K Memory stack (hex wide) (G)
G646C	MM8EJ	8K Memory stack (B)
G650	MM8AB	PDP8A 16K Memory stack (hex wide) (G)
H212	MM8EJ	8K Memory stack (B)
H219A	MM8AA	PDP8A 8K Memory control (hex wide) (G)
H219B	MM8AB	PDP8A 16K Memory control (hex wide) (G)
H220	MM8E	Memory stack (P,M)
H220	MP8E	Memory stack (P)
M1703C		(B)
M1703 		(B)
M1709 		(B)
M512	DK8ED	(P)
M518	DK8EP	Programmable Real Time Clock (requires M860) (L,P,H)
M518	DK8EF	Programmable Real Time Clock (requires M860) (F)
M518	DS8EA	Schmidt Trigger (F)
M7104	RK8E	RK01 Disk Interface (L)
M7105	RK8E	RK01 Disk Interface (L)
M7106	RK8E	RK01 Disk Interface (L)
M8300	KK8E	Major registers (B,P,M,F)
M8310	KK8E	Major register control (B,P,M,F)
M8315	KK8A	PDP-8/A CPU board (hex wide) (G,F)
M8316	DKC8AA	PDP-8/A I/O serial/parallel/clock (hex wide) (G)
M8317	KM8AA	PDP-8/A bootstrap, powerfail (hex wide) (G,F)
M8317	KM8AB	PDP-8/A Memory extender (hex wide) (G)
M8317YC	KM8AC	PDP-8/A Memory extender, bootstrap, powerfail (hex wide) (F)
M8319	KL8A	PDP-8/A 4 channel I/O (F)
M8320	KK8E	Bus loads (B,P,M,F)
M8321	TM8E	Magtape output control module (M,F)
M8322	TM8E	Magtape control and data break module (M,F)
M8323	TM8E	Magtape transport status and control module (M,F)
M8326	DB8EA	Interprocessor buffer (F)
M8327	TM8E	Magtape register module (M,F)
M833		(B)
M8330	KK8E	Timing board (B,P,M,F)
M8330YB	KM8F	Timing board (F)
M8331	TA8E	DEC Cassette control (F)
M8335	VT8E	(L)
M8336	VT8E	Video Display Clock and Frequency Divider (M)
M8337	VT8E	Video Display Line Buffer Module (M)
M8340	KE8E	Extended arithmetic element (P,M,F)
M8341	KE8E	Extended arithmetic element (P,M,F)
M8342	LC8E	Centronics printer control (F)
M835		(B)
M8350	KA8E	External positive I/O bus interface (B,P,M,F)
M8357	RX8E	RX01/RX02 interface (B,F)
M8360	KD8E	Data Break Interface (P,M)
M8365	LC8P	LA180 printer control (F)
M8366	LQP8E	LQP01 printer control (F)
M837	MC8E	Extended Memory and Time Share Control (B,P)
M837	KM8E	Extended Memory and Time Share Control (H,F)
M839	DP8EA	Synchronous Modem (P,M,H,F)
	DP8EB	Synchronous Modem (Bell series 300 modem) (H)
M840	PC8E	High speed paper tape reader/punch (PC04) interface (P,M)
M841	LE8XX	Line Printer Control (P)
M841	LE8C	Data Products printer control (F)
M8416	KT8AA	PDP8A Memory Management (hex wide) (G,F)
M8417	MSC8AA	PDP8A 16K MOS Memory (hex wide) (G)
M8417	MSC8AB	PDP8A 32K MOS Memory (hex wide) (G)
M8417	MSC8DJ	PDP8A 128K MOS Memory (hex wide) (G)
M842	XY8E	X/Y Plotter Control (P,M,H)
M843	CR8E	Card reader control (F)
M8430	KW8EW	Alarm timer (F)
M8433	RL8A	Disk controller for RL01/02 (hex wide) (G)
M847	MI8E	Hardware Bootstrap Loader (P)
M847	MI8EN	Hardware Bootstrap Loader for RK8E (F)
M847	MI8EP	Hardware Bootstrap Loader for RX01/RX02 (F)
M848	KP8E	Power fail and auto-restart (B,P,M,H,F)
M849	KK8E	RFI shield (B,M)
M860	DK8ED	Programmable Real Time Clock (P)
M860	DK8EF	Programmable Real Time Clock (L)
M860	DK8EP	Programmable Real Time Clock (P,H)
M863	DR8E	12 Channel Buffered Digital I/O (P,F)
	DR8EA	12 Channel Buffered Digital I/O (H)
M866	DP8EA	Synchronous Modem (Bell series 200 modem) (P,M,H,F)
	DP8EB	Synchronous Modem (Bell series 300 modem) (H)
	DP8EP	Parity generator checker for modem use (H)
M865		Console Teletype Control (B)
M8650	KL8E	Asynchronous Data Control (B,P,M,H,F)
M8653	KL8M	Modem Control (F)
M8655	KL8JA	Terminal Control (UART based) (G,B,F)
M868	TD8E	DECtape Control (P,M,F)
M869	VC8E	(requires M885) (P)
M882	DK8EA	Real Time Clock (Line Frequency) (P,H,F)
M8830	DK8EC	Real Time Clock (Crystal) (G,H,F)
M884	KG8E	Parity Generator Detector (P)
M884	KG8EA	Parity Generator Detector (F)
M885	VC8E	(requires M869)

Summary-line: 21-Aug  [email-masked]  #fan-fold fossils
Date: Fri, 21 Aug 92 12:40:46 CDT
From: [email-masked] (Ed McGuire)
To: [email-masked]
Cc: [email-masked]
Subject: fan-fold fossils
   Date: Thu, 20 Aug 92 04:10:48 CDT
   From: "Andrew Luebker" <[email-masked]>

Date: Fri, 21 Aug 92 12:40:46 CDT
From: [email-masked] (Ed McGuire)
To: [email-masked]
Cc: [email-masked]
In-Reply-To: "Andrew Luebker"'s message of Thu, 20 Aug 92 04:10:48 CDT <[email-masked]>
Subject: fan-fold fossils
   Date: Thu, 20 Aug 92 04:10:48 CDT
   From: "Andrew Luebker" <[email-masked]>

   Twice now, I have dragged this box away from the dumpster, thinking
   it might be of some value to PDP archeologists.  It contains 14 cartons
   of blank, unused gray DEC fan-fold paper tape.  Is this a museum item,
   or are people still punching away long tickertapes?

     -Andrew Luebker-  [email-masked]

Some of us have paper tape reader/punches and would love to get our
grimy hands on your paper tape :)

Summary-line: 22-Aug      [email-masked]  #fan-fold fossils
Date: Sat, 22 Aug 92 12:48:25 -0400
From: [email-masked] (Christopher R. Zach)
To: [email-masked]
Cc: [email-masked]
Subject: fan-fold fossils

Date: Sat, 22 Aug 92 12:48:25 -0400
From: [email-masked] (Christopher R. Zach)
To: [email-masked]
Cc: [email-masked]
In-Reply-To: "Andrew Luebker"'s message of Thu, 20 Aug 92 04:10:48 CDT <[email-masked]>
Subject: fan-fold fossils

Mail it to:

Chris Zach
1803 Research Bvld, Sutie 302
Rockville, MD 20850

I have a PDP-8 with a royal McBee tape punch, and I am very low on paper tape.

Thanks
CZ

Summary-line: 22-Aug         [email-masked]  #Re:  fan-fold fossils
Date: Sat, 22 Aug 92 23:53:26 PDT
From: [email-masked] (Paul Hardy)
To: [email-masked], [email-masked]
Subject: Re:  fan-fold fossils
Cc: [email-masked]

Date: Sat, 22 Aug 92 23:53:26 PDT
From: [email-masked] (Paul Hardy)
To: [email-masked], [email-masked]
Subject: Re:  fan-fold fossils
Cc: [email-masked]

I have heard that paper tape is still being manufactured for use with
computers in mainland China.  Does anyone have a source for this stuff?

                                   --Paul

Summary-line: 23-Aug    [email-masked]  #Re: fan-fold fossils 
To: [email-masked] (Paul Hardy)
Cc: [email-masked]
Subject: Re: fan-fold fossils 
Date: Sun, 23 Aug 92 02:04:18 -0600
From: Chris Petrilli <[email-masked]>

To: [email-masked] (Paul Hardy)
Cc: [email-masked]
Subject: Re: fan-fold fossils 
In-Reply-To: (Your message of Sat, 22 Aug 92 23:53:26 PDT.)
             <[email-masked]> 
Date: Sun, 23 Aug 92 02:04:18 -0600
From: Chris Petrilli <[email-masked]>

>>>>> On Sat, 22 Aug 92 23:53:26 PDT, [email-masked] (Paul Hardy) said:

Paul> I have heard that paper tape is still being manufactured for use with
Paul> computers in mainland China.  Does anyone have a source for this stuff?

Well, if you become VERY needy, I have 6 cases (8 rolls each) of paper
tape that I might be able to dig out of storage.  I'm not sure whether
it runs on PDP-8 tape drives or not though, it was originally running
on a DG machine, but it also works on my Teletypes :)

Chris
--
| Chris Petrilli                                             ____
| [email-masked]             ``Quayle is a bozoe.'' \  /
| I don't even speak for myself.                              \/

Date: Mon, 31 Aug 92 17:23:41 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: PDP-8/I

Date: Mon, 31 Aug 92 17:23:41 CDT
From: Douglas W. Jones <[email-masked]>
To: [email-masked]
Subject: PDP-8/I

I have located two PDP-8/I machines, one of which worked when last used in
1987, one of which is in unknown condition.  The machines are mounted in
third-party X-ray diffraction machines, and they share an auxiliary DEC
cabinet that holds an Ampex 9-track tape drive and a DF 32 disk drive (32K
words capacity).  Both tape and disk also worked as of 1987.  They share the
peripherals through some kind of bus mux.  Both machines are minimal
systems, with only 4K of main memory.  Be aware that the Ampex 9-track
tape drive reads and writes tape in a distinctly odd format!  As far as
I understand it, it reads or writes a pair of 8 bit bytes for each 12
bit word transferred to or from tape, in 8-4 format.  It can write 9-track
tapes that others can read, but it may not be able to read arbitrary data
from such tapes!

The owner (who has previously disposed of a straight 8 to someone in
Indiana, he forgets the name) would prefer to find a good home for them
instead of junking them, since unless he can line up a buyer beforehand,
the best our surplus operation could get for these machines is around $10
for the CPU and perhaps $25 for the tape drive to someone who doesn't
suspect it's odd 12 bit wiring.

I'll put anyone who's seriously interested in these antiques in contact
with their current owner, since they don't fit into any of my PDP-8
restoration plans.  If you're worried about physically getting them,
they're in Iowa City, on I-80 an hour east of the Mississippi River.
Be careful moving that disk, by the way, it's one of the oldest (and
smallest) disks I know of that may still be in good working condition.

					Doug Jones
					[email-masked]

Date: Mon, 31 Aug 92 18:32:15 CDT
From: [email-masked] (Ed McGuire)
To: [email-masked]
Cc: [email-masked]
Subject: PDP-8/I
   they're in Iowa City, on I-80 an hour east of the Mississippi River.
                                         ^^^^

Date: Mon, 31 Aug 92 18:32:15 CDT
From: [email-masked] (Ed McGuire)
To: [email-masked]
Cc: [email-masked]
In-Reply-To: Douglas W. Jones's message of Mon, 31 Aug 92 17:23:41 CDT <[email-masked]>
Subject: PDP-8/I
   they're in Iowa City, on I-80 an hour east of the Mississippi River.
                                         ^^^^

Which U of I did you mean? :)

To: [email-masked]
Subject: Re:  PDP-8/I
Cc: [email-masked]
Date: 31 Aug 92 19:22:15 PDT (Mon)
From: [email-masked]

To: [email-masked]
Subject: Re:  PDP-8/I
Cc: [email-masked]
Date: 31 Aug 92 19:22:15 PDT (Mon)
From: [email-masked]

>I have located two PDP-8/I machines, one of which worked when last used in
>1987, one of which is in unknown condition.  The machines are mounted in
>third-party X-ray diffraction machines, and they share an auxiliary DEC
>cabinet that holds an Ampex 9-track tape drive and a DF 32 disk drive (32K
>words capacity).  Both tape and disk also worked as of 1987.  They share the
>peripherals through some kind of bus mux.  Both machines are minimal
>systems, with only 4K of main memory.  Be aware that the Ampex 9-track
>tape drive reads and writes tape in a distinctly odd format!  As far as
>I understand it, it reads or writes a pair of 8 bit bytes for each 12
>bit word transferred to or from tape, in 8-4 format.  It can write 9-track
>tapes that others can read, but it may not be able to read arbitrary data
>from such tapes!
[...]
The machines are probably Picker X-Ray diffractometers (FACS-I). If so, the
interface to the magtape may be a wierd one. The one that I used could only
transfer the low order 8-bits of a word and the data could only be in Field 0.
High order bits were ignored on read and on write. Why would anyone bother to
wire up the support for specifing the DMA Field in an IOT, anyways...

I have a driver for the magtape for the 4K Disk Monitor System. It does require
the use of the Field 1 swap area for the compose/decompose of the data so you
have to have at least an 8K machine, in which case, why aren't you using
OS/8? :-)

The driver simulates a 1024 block DECtape (supported of course by the 4K DMS).
To do this it uses a tape format that is 

  BOT
  long gap
  EOF
  two's complement block number (0000)
  long gap
  EOF
  128 bytes
  128 bytes
  long gap
  EOF
  two's complement block number (7777)
  long gap
  EOF
  128 bytes
  128 bytes
  long gap
  EOF
  two's complement block number (7776)
  long gap
  EOF
  128 bytes
  128 bytes
  ...

The key to rewriting records in the middle of the tape is the long gap stuff.
I also have the formatter that produces the tapes above, and a dump-restore
program for DF-32 to tape. These will be of great use to the myriad of happy
programmers still using the 4K-DMS, PAL-D, and FOCAL-D. The driver is loaded
from the dedicated driver area of the 4K-DMS and overlays the DECtape driver.
It runs with interrupts enabled (as would be the case with the 4K-DMS), and
is loaded as a paper-tape overlay during the installation of the 4K-DMS.
I wrote it in the late 1960's.

Since the TU-10 and TU-20 drives are so much better and can use core-dump, it
is possible to write an OS/8 driver for both DECtape simulation and a more
conventional sequential tape format. It was even possible to run an OS-8
system on magnetic tape only with no disk drive. S l o o o o w . . .

If there is a great demand for this software should I put it somewhere for
FTP access?