Other SMS300/8X300/8X305 uses?

Tony Duell ard.p850ug1 at gmail.com
Sun Nov 27 08:57:49 CST 2016

On Sun, Nov 27, 2016 at 8:48 AM, jos <jos.dreesen at greenmail.ch> wrote:
> On 27.11.2016 08:10, Tony Duell wrote:

>> There's an 8X300 on the hard disk controller (Philips X1215 drive) for the
>> Philips P854 computer. But I suspect that is too obscure even for this
>> list.
>  Why too obscure ?

How many P854 machines have you come across :-)

> The Philips P851 mini also uses a 8X300 / 8X330 combo for floppy &  HD
> controller.

The P851 and P854 use the same bus, essentially (the P854 has memory
management logic in the CPU, so has more address lines) and many
I/O boards will work in both machines. So I thought this was going to be
the same board

> Picture of this controller and dumps of proms are on :
> ftp://ftp.dreesen.ch/WD1001

But it isn't -- quite. I wonder if I have a very early version of it, as the
only info i have on it is a photocopy of a hand-drawn block diagram.

My P854 has the normal 2-board set for the floppy controller, I have
an indentical one in the P851. Whether the hard disk controller could
handle floppies, or whether that was added to later versions I don't
know, I do have the same headers at the front edge of the board (the
50 pin one is for the X1215 hard drive which alas I don't have).

> If there is a chance to have a good pic of the P851 frontpanel I would
> appriciate it !

I can take one. You do mean P851 and not P854 here, I assume (I have

> Too bad the 851 CPU uses ASIC for datapaths & control logic, so I cannot get
> this system up and running since it misses the control one.

The PLANET (PLA NETwork)? The one that handles microcode branches? I only
have one spare (and 4 spare SPALUs (Scratch Pad and Arithmetic Logic Unit) --
the 4-bit bit-slice for the data path) and I really need to keep it as
a spare for
my P851.


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