Boot Rom for KDF11-BA

[Douglas Taylor]

At 03:10 PM 10/16/2004, you wrote:
>On Oct 11 2004,  3:51, mehditk2 at juno.com wrote:
> >
> > Hi,
> >
> > Does anyone have a KDF11-B3 boot rom or any other version which
> > can boot RX33 or an MSCP device on my KDF11-BA. I will pay for
> > that and I will be very thankful since I have not to buy a Eprom
> > programmer to burn the immages.
>
>KDF11-B3 isn't one ROM, it's an upgrade kit consisting of two EPROMs
>plus instructions.  It's more usual to refer to the ROMs themselves by
>the actual numbers or the processor suffix.  The ROMs in the -B3 kit
>are 23-183E4 and 23-184E4, as far as I remember; that's the -BF
>version, but most versions of the KDF11 ROMs work with MSCP devices.
>  For example, people have used RD31 drives on an RQDX3 with -BE ROMs,
>although it wasn't officially supported until -BG.  The next version
>was 23-380E4 and 23-381E4, which would make the processor a KDF11-BG.
>
>There's a list of ROMs at
>http://www.dunnington.u-net.com/public/DECROMs/ (see the file called
>ROMlist).
>
>You can see which revisions officially support various MSCP devices in
>Micronote 43, which you can find in various places including
>http://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/hardware/micronotes/numerical/micronote43.txt
>
>BTW, the EPROMs for a KDF11-B are unusual 24-pin 8Kx8 devices; normal
>2764-style 8Kx8 devices will not do because they're 28-pin.
>
>--
>Pete                                            Peter Turnbull
>                                                 Network Manager
>                                                 University of York

I looked into this and found that the people who fool around with old 
arcade video games have the same problem with EPROMs, here is one fellows' 
solution to using a standard 2764 PROM in place of the rare Motorola 68764 
(which I think is the one on the KDF11-B quad CPU board).  Haven't tried it 
though.  I could never find the pin out of the Motorola part....  BTW, my 
PROM programmer had no problem identifying and reading the 24 pin DEC Prom, 
I guess if I could find a blank one I could burn it.

Doug Taylor

You Build It: Hero Rom UpgradeYou build it: Hero Rom Upgrade
OK so you downloaded the new ROM version, but you cant find a 68764 (8K 
Eprom in
24 pin package). Well here is a little conversion you can do to allow you 
to use
a 2764 (8K Eprom in 28 pin package).

  1  tie high (+5)
  2  tie to socket #21
  28 tie to socket #24
  27 tie high (+5)


   24 Pin    28 Pin     Notes
--------------------------
    Vcc 24   26 N/C     OK to pass through
    A8  23   25 A8      OK to pass through
    A9  22   24 A9      OK to pass through
    A12 21   23 A11     Socket to prom#2, pin to socket #18
    E   20   22 OE      OK to pass through
    A10 19   21 A10     OK to pass through
    A11 18   20 CE      Socket to prom#23, pin to ground