Subject: DF32x4 questions; software needed

From: "Dr. Charles E. Morris" <[email-masked]>
Date: Fri Apr 4 12:32:35 2003

My "DF32x4" disk emulator is alive and talking to my 8/L and appears to be
reading and writing blocks of data correctly. There are a few instructions
that I did not implement (e.g. the "Maintenance" IOT's 6631-4 which the
manual says are only used in "diagnostic programming". Also the DCEA
instruction does not clear the extended address and EA registers - it would
have taken quite a bit more logic to implement and there was no more room on
the PC board; additionally the DEAL instruction would be used anyway, which
combines the clear action with a load of these registers from the AC - so
the clear would be superfluous. The DEAL and DEAC load/read register
commands are, of course, implemented).

Ethan Dicks has pointed out that I should look at the drivers in OS8 and
TSS8 to see if this will be a compatibility problem (i.e. they may expect to
be able to clear EMA and EA for some reason, rather than loading them from
the AC). Can anyone tell me where to find the source code so I can verify
this?

Also, I would love to have a paper tape copy of 4K Disk System Builder to
start a build of Disk Monitor from scratch (I already have a copy of a DF32
build thanks to David Gesswein). Anyone?

thanks
Charles

---

From: Ethan Dicks <[email-masked]>
Date: Fri Apr 4 13:16:00 2003

--- "Dr. Charles E. Morris" <[email-masked]> wrote:
> My "DF32x4" disk emulator is alive and talking to my 8/L and appears to
> be reading and writing blocks of data correctly.

Public congratulations!

---
> manual says are only used in "diagnostic programming".  - it
> would

---

> There are a few instructions that I did not implement...
> ... the DCEA instruction does not clear the extended address and EA
> registers... Ethan Dicks has pointed out that I should look at the
> drivers in OS8 and TSS8 to see if this will be a compatibility problem.

Sorry I didn't get back you earlier, but over on David Gesswein's
searchable software archive...

RTS/8 DF-32 driver (probably will never matter, but good background info)

http://www.pdp8.net/pdp8cgi/os8_html/RF08.PA?act=file;fn=images/misc_dectapes/DEC-S8-ORTSA-C-UC2.tu56;blk=290,10,0;to=auto

A code snippet from 

http://www.pdp8.net/pdp8cgi/os8_html/DX.12?act=file;fn=linctape-images/os8l/ds8-2nd-tape.linc;blk=184,80,0;to=auto

/ THE ROUTINE LINCDO CLEARS DF32 FLAGS TO ALLOW
/ A LINC DATA BREAK.  IF A DIFFERENT DATA BREAK
/ DEVICE IS IN USE THE APPROPRIATE MODIFICATIONS
/ SHOULD BE MADE.  (NOTE BY CLEARY)

LINCDO,	0		/EXECUTE A LINC PROGRAM
	DCMA		/CLEAR ANY DATA BREAK FLAGS
	DCEA		/THESE ARE FOR DF32
	TAD (LINPRO)
	ISSP		/SET UP LINC PC
	CLA
	TAD (10)
	ICON		/SELECT LINC
	TAD (2)
	ICON		/START LINC
	NOP
	TAD (-1)
	ICON		/DESELECT LINC
	CLA
	JMP I LINCDO

... shows the use of DMCA and DCEA to clear a disk, rather than DEAL.

Not exactly what you were looking for, but perhaps someone else has the
sources at their fingertips (I'm behind a restrictive firewall at the
moment, so my searching is somewhat limited).

As I mentioned earlier, I've only done some basic DF32 twiddling
from a PDP-8/i to prove that the interface mostly worked (and to
diagnose my repairs of a smoked rotation sensor board).  I've never
had the joy of an 8K machine + DF32s, so I've never had an OS to
explore them.

-ethan