D Bit boot PROMs
================

This directory contains my clean-room re-implementations of some of
DEC's 23-xxxA9-00 boot PROMs (as used on the M9312 boot/diag board, as
well as the on-board PROM sockets on the 11/24 and 11/44).  These have
been tested only under E11, not against real hardware, so it's possible
there are bugs, and I definitely need to fix my understanding of the
various entry points (currently the diags are never called).

All of these files are in the public domain.  They may be copied and/or
used for any purpose.

Files:  (.mac is source, .bin is image as it appears in PDP-11 memory)

dkprom	DK: (RK02/03/05), DT: (TU55/TU56)

dlprom	DL: (RL01/02)

dmprom	DM: (RK06/07)

duprom	DU: (MSCP disks)

dxprom	DX: (RX01)

dyprom	DY: (RX02)

You can build the binary file under RT-11 as follows:

MACRO DKPROM
LINK DKPROM/NOBITMAP

The bootstrap is now in the first 128. bytes of DKPROM.SAV.  Note that
this is an image of the bootstrap as it will be seen by the PDP-11;  in
order to burn it into a boot PROM (82S130, Am27S13, 74S571) you need to
re-shuffle the data because the PROM is only 4 bits wide (and only half
of it is used), and is re-assembled into 16-bit words on the fly by the
M9312 hardware.  This can be done using this DOS program:

	ftp://ftp.dbit.com/pub/ibmpc/util/cvt9312.asm  (source/doc)
	ftp://ftp.dbit.com/pub/ibmpc/util/cvt9312.com  (executable)

John Wilson <wilson@dbit.com>  21-Oct-2000