6 Sep
2015
6 Sep
'15
2:41 p.m.
Several people asked, here's the scoop:
The common proms for HP 21MX M/E/F are 1K, 4K, and 8K.
1K are used for either loader roms on the cpu board or microcode on the FAB
4K are used for microcode on the FAB or FEM
8K are used for microcode on the FEM
The manuals you'll want to print and keep handy:
HP 12992 Loader Roms Installation Manual, 12992-90001 (April '86)
HP 1000 M/E/F-series Firmware Installation and Reference Manual, 12791-90001
(September, '83)
I believe these are both on bitsavers. They are "must have" manuals.
These are all bipolar proms, and most modern prom programmers will not be
able to program them. I use a Data I/O 29B (with Unipak 2B), and it can
program all these parts. Those programmers appear on ebay from time to time
at around roughly $400.
The blank proms are not terribly easy to find these days. Ebay has them
occasionally, but your best bet is sites that cater to arcade machine
repair.
Here's a non-exhaustive but useful list of compatible parts for each:
1K parts
MMI 6301
Harris 7611
Signetics N82S129
National 74S287
TI 24S10
AMD 27S21
Fujitsu 7114 (possibly 7052 as well, need to verify that)
4K parts
Signetics N82S141
Harris 7641
MMI 6341
8K parts
Signetics N82S181
Harris 7681
MMI 6381
6 Sep
6 Sep
2:47 p.m.
Intersting to note: many times i have used eproms in place of these proms.
Usually, flash parts are faster, so better suited to the task.
Em 06/09/2015 15:42, "Jay West" <jwest at classiccmp.org> escreveu:
Several people asked, here's the scoop:
The common proms for HP 21MX M/E/F are 1K, 4K, and 8K.
1K are used for either loader roms on the cpu board or microcode on the FAB
4K are used for microcode on the FAB or FEM
8K are used for microcode on the FEM
The manuals you'll want to print and keep handy:
HP 12992 Loader Roms Installation Manual, 12992-90001 (April '86)
HP 1000 M/E/F-series Firmware Installation and Reference Manual,
12791-90001
(September, '83)
I believe these are both on bitsavers. They are "must have" manuals.
These are all bipolar proms, and most modern prom programmers will not be
able to program them. I use a Data I/O 29B (with Unipak 2B), and it can
program all these parts. Those programmers appear on ebay from time to time
at around roughly $400.
The blank proms are not terribly easy to find these days. Ebay has them
occasionally, but your best bet is sites that cater to arcade machine
repair.
Here's a non-exhaustive but useful list of compatible parts for each:
1K parts
MMI 6301
Harris 7611
Signetics N82S129
National 74S287
TI 24S10
AMD 27S21
Fujitsu 7114 (possibly 7052 as well, need to verify that)
4K parts
Signetics N82S141
Harris 7641
MMI 6341
8K parts
Signetics N82S181
Harris 7681
MMI 6381
3 p.m.
Alexander wrote...
-----
Intersting to note: many times i have used eproms in place of these proms.
Usually, flash parts are faster, so better suited to the task.
-----
Loader roms:
You may be able to get by with that on loader roms. I've never found eproms that were
functional & pin compatible. What ones did you use for the 1K variety?
Microcode:
I doubt seriously the eproms would be stable for microcode. HP specs 5ns speed parts for
the microcode; what eproms work and can hit those speeds? I suspect this is one of those
"might seem to work" but is a really bad idea.
J
5 p.m.
Jay, no one is pin compatible, I always make adapters. But at least I make
it work :D
2015-09-06 16:00 GMT-03:00 Jay West <jwest at classiccmp.org>:
Alexander wrote...
-----
Intersting to note: many times i have used eproms in place of these proms.
Usually, flash parts are faster, so better suited to the task.
-----
Loader roms:
You may be able to get by with that on loader roms. I've never found
eproms that were functional & pin compatible. What ones did you use for the
1K variety?
Microcode:
I doubt seriously the eproms would be stable for microcode. HP specs 5ns
speed parts for the microcode; what eproms work and can hit those speeds? I
suspect this is one of those "might seem to work" but is a really bad idea.
J
7 Sep
7 Sep
11:32 a.m.
On 09/06/2015 2:00 PM, Alexandre Souza wrote:
Jay, no one is pin compatible, I always make adapters.
But at least I make
it work :D
2015-09-06 16:00 GMT-03:00 Jay West <jwest at classiccmp.org>:
> Alexander wrote...
> -----
> Intersting to note: many times i have used eproms in place of these proms.
> Usually, flash parts are faster, so better suited to the task.
> -----
>
> Loader roms:
> You may be able to get by with that on loader roms. I've never found
> eproms that were functional & pin compatible. What ones did you use for the
> 1K variety?
>
> Microcode:
> I doubt seriously the eproms would be stable for microcode. HP specs 5ns
> speed parts for the microcode; what eproms work and can hit those speeds? I
> suspect this is one of those "might seem to work" but is a really bad
idea.
>
> J
>
>
>
As Jay points out, it is the access speed required by the device you are
substituting the EPROM for a ROM/PROM that counts. In some cases the 100
to 400ns access speed of EPROMs won't matter (clock of under 1mHz for
400ns 2716s to around 4mHz for 100ns EPROMs), but if you are running
10mHz or faster reads then I suspect you will have problems unless you
find faster devices than EPROMs for your substitute ROM/PROM...
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
11:34 a.m.
As I said in the original post I wrote, sometimes you gotta use flash
devices that are WAY faster than common EPROMs...
2015-09-07 12:32 GMT-03:00 John Robertson <jrr at flippers.com>:
On 09/06/2015 2:00 PM, Alexandre Souza wrote:
Jay, no one is pin compatible, I always make
adapters. But at least I make
it work :D
2015-09-06 16:00 GMT-03:00 Jay West <jwest at classiccmp.org>:
Alexander wrote...
> -----
> Intersting to note: many times i have used eproms in place of these
> proms.
> Usually, flash parts are faster, so better suited to the task.
> -----
>
> Loader roms:
> You may be able to get by with that on loader roms. I've never found
> eproms that were functional & pin compatible. What ones did you use for
> the
> 1K variety?
>
> Microcode:
> I doubt seriously the eproms would be stable for microcode. HP specs 5ns
> speed parts for the microcode; what eproms work and can hit those
> speeds? I
> suspect this is one of those "might seem to work" but is a really bad
> idea.
>
> J
>
>
>
> As Jay points out, it is the access speed required by the device you are
substituting the EPROM for a ROM/PROM that counts. In some cases the 100 to
400ns access speed of EPROMs won't matter (clock of under 1mHz for 400ns
2716s to around 4mHz for 100ns EPROMs), but if you are running 10mHz or
faster reads then I suspect you will have problems unless you find faster
devices than EPROMs for your substitute ROM/PROM...
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
1:47 p.m.
But I do think there's merit in Alexandre's general argument that one could
theoretically emulate the older bipolar PROMs with some mix of modern
components ... and the programmable device would be (a) more easily
obtainable than the old bipolar PROMs and (b) programmable with
inexpensive, contemporary USB device programmers which are definitely big
positives.
Best,
Sean
On Mon, Sep 7, 2015 at 1:24 PM, Al Kossow <aek at bitsavers.org> wrote:
On 9/7/15 8:34 AM, Alexandre Souza wrote:
sometimes you gotta use flash
devices that are WAY faster than common EPROMs...
and sometimes that won't work, because the hold time of fast
devices is too short.
6:05 p.m.
On 09/07/2015 12:47 PM, Sean Caron wrote:
But I do think there's merit in Alexandre's
general argument that one could
theoretically emulate the older bipolar PROMs with some mix of modern
components ... and the programmable device would be (a) more easily
obtainable than the old bipolar PROMs and (b) programmable with
inexpensive, contemporary USB device programmers which are definitely big
positives.
Most likely, one could use a parallel modern EPROM that is
as fast as the old bipolar PROM.
Of course, the pinout would be totally different, probably
in a larger size package with way more pins.
This one is 256K and 70 ns access time.
http://www.digikey.com/product-detail/en/AT28HC256-70JU/AT28HC256-70JU-ND/2…
If you REALLY need it fast, Winbond has a 45 ns EPROM, but
not in stock at Digi-Key.
That's their W27C512-45Z
Jon
6:20 p.m.
Sean wrote....
-----
But I do think there's merit in Alexandre's general argument that one could
theoretically emulate the older bipolar PROMs with some mix of modern components ... and
the programmable device would be (a) more easily obtainable than the old bipolar PROMs and
(b) programmable with inexpensive, contemporary USB device programmers which are
definitely big positives.
-----
I agree... and have suggestions. Prior art exists, I have seen the arcade crew use
adapters to modify the pins of newer devices to be compatible.
For loader roms, there are about 10 official images from HP. Plus, most users (myself for
sure) would want around 2 images that are user-created. The system board supports 4 roms,
selectable by front panel. The issue with the solution the arcade crew has done - the
adapters make the new memory devices too tall to allow clearance above. In chassis after a
certain date code there is a cutout to access the rom sockets without removing the system
board. In those, the clearance issue is the bottom of the memory controller. In prior
revs, the issue is the metal work not providing clearance. I'm not saying a solution
can't be found, but whoever develops such a device needs to be aware of the clearance
issues particularly on the older rev machines. The only thing I can think of that is
likely to have proper clearance is a board that has pins going to each 4 rom sockets, and
the replacement memories are placed under the board - not on top of it - carefully
avoiding existing chips on the system board. Regardless... whoever designs such a board
needs to have a 21MX in front of them to assure clearances. Also, I'd have to check,
but the precise spacing between the rom sockets may well be different between the M and E
versions. All that being said, it would be nice if the board supported say 12 images, any
4 of which could be selected as active.
Now, here's a better take on the problem.... design a card that goes into a memory
slot. Most all machines have many empty memory slots even when full of memory. Then a
ribbon cable could go down to a paddle board that plugs into the 4 rom sockets. The board
in the memory slot could get power straight from the backplane. The ribbon/paddleboard
relieves the clearance problem. Extra points if this board also houses 1mw of ram and
connects to the memory controller as usual. Even better points if the board replaces the
memory controller and provides both 1mw ram plus loader roms :>
For microcode, you'd sure have to find a way to get past the speed issue. Since the
21MX's take microcode on the cpu board, or a FAB board, or a FEM board (and the
"fab" is very different on the 21MX/M)... you've got a lot of choices. My
bet - the most functional approach is to ignore trying to deal with microcode prom
replacement on the cpu and fab boards. Instead, provide a single "new"
"FEM" board that presents 24 bit wide memory modules of appropriate speed.
Basically, this becomes a WCS board - with modern memory devices. There's a pretty
large number of microcode options that could get stuffed into such a device. The only down
side - FEM boards take an I/O slot, and one HP OS in particular will have an issue where
I/O slots are pre-allocated and not configurable at sysgen time. Extra points if the board
can also include devices that everyone always puts in - namely a TBG and HSterm/BACI. Not
sure how one could handle the select code logic in one slot, would probably need
paddleboards. But my advice - solve the speed issue first ;)
J
7:03 p.m.
If I were doing it.
First you need to find out if it needs OC output.
There are many flash parts in surface mount that can have
the higher speeds.
Add some 74LVC245 to give bus drive needed, also surface mount.
All on a little PC board. There would be a lot of wasted space in the
flash but what the heck.
Put an edge connector on the board to deal with programming.
All will fit in a smaller space than the original part.
Dwight
From: jwest at classiccmp.org
To: cctalk at classiccmp.org
Subject: RE: 21MX proms (per request)
Date: Mon, 7 Sep 2015 17:20:48 -0500
Sean wrote....
-----
But I do think there's merit in Alexandre's general argument that one could
theoretically emulate the older bipolar PROMs with some mix of modern components ... and
the programmable device would be (a) more easily obtainable than the old bipolar PROMs and
(b) programmable with inexpensive, contemporary USB device programmers which are
definitely big positives.
-----
I agree... and have suggestions. Prior art exists, I have seen the arcade crew use
adapters to modify the pins of newer devices to be compatible.
For loader roms, there are about 10 official images from HP. Plus, most users (myself for
sure) would want around 2 images that are user-created. The system board supports 4 roms,
selectable by front panel. The issue with the solution the arcade crew has done - the
adapters make the new memory devices too tall to allow clearance above. In chassis after a
certain date code there is a cutout to access the rom sockets without removing the system
board. In those, the clearance issue is the bottom of the memory controller. In prior
revs, the issue is the metal work not providing clearance. I'm not saying a solution
can't be found, but whoever develops such a device needs to be aware of the clearance
issues particularly on the older rev machines. The only thing I can think of that is
likely to have proper clearance is a board that has pins going to each 4 rom sockets, and
the replacement memories are placed under the board - not on top of it - carefully
avoiding existing chips on the system board. Regardless... whoever designs such a board
needs to have a 21MX in front of them to assure clearances. Also, I'd have to check,
but the precise spacing between the rom sockets may well be different between the M and E
versions. All that being said, it would be nice if the board supported say 12 images, any
4 of which could be selected as active.
Now, here's a better take on the problem.... design a card that goes into a memory
slot. Most all machines have many empty memory slots even when full of memory. Then a
ribbon cable could go down to a paddle board that plugs into the 4 rom sockets. The board
in the memory slot could get power straight from the backplane. The ribbon/paddleboard
relieves the clearance problem. Extra points if this board also houses 1mw of ram and
connects to the memory controller as usual. Even better points if the board replaces the
memory controller and provides both 1mw ram plus loader roms :>
For microcode, you'd sure have to find a way to get past the speed issue. Since the
21MX's take microcode on the cpu board, or a FAB board, or a FEM board (and the
"fab" is very different on the 21MX/M)... you've got a lot of choices. My
bet - the most functional approach is to ignore trying to deal with microcode prom
replacement on the cpu and fab boards. Instead, provide a single "new"
"FEM" board that presents 24 bit wide memory modules of appropriate speed.
Basically, this becomes a WCS board - with modern memory devices. There's a pretty
large number of microcode options that could get stuffed into such a device. The only down
side - FEM boards take an I/O slot, and one HP OS in particular will have an issue where
I/O slots are pre-allocated and not configurable at sysgen time. Extra points if the board
can also include devices that everyone always puts in - namely a TBG and HSterm/BACI. Not
sure how one could handle the select code logic in one slot, would probably need
paddleboards. But my advice - solve the speed issue first ;)
J
6 Sep
6 Sep
3 p.m.
On Sun, Sep 6, 2015 at 11:41 AM, Jay West <jwest at classiccmp.org> wrote:
Several people asked, here's the scoop:
The common proms for HP 21MX M/E/F are 1K, 4K, and 8K.
1K are used for either loader roms on the cpu board or microcode on the FAB
4K are used for microcode on the FAB or FEM
8K are used for microcode on the FEM
The loader PROMs are 256x4 while the firmware PROMs are either 512x8
or 1024x8. The firmware has some interesting code to unpack the 256x4
loader PROMs into 64x16 format in memory, and patch in the I/O select
code while it is doing it.
I programmed at least one loader PROM using a BP Micro programmer. I
forget exactly which PROM part I used. I probably have a very small
number of blank PROMs left. I forget what loader PROM I swapped out
and which one I swapped in. Sometime I'll have to fire up the system
and dump the loaders PROMs into memory and check which ones I
currently have installed, and make some notes so I don't have to
wonder again later.
-Glen
3:04 p.m.
Glen wrote....
----
The loader PROMs are 256x4 while the firmware PROMs are either 512x8 or 1024x8. The
firmware has some interesting code to unpack the 256x4 loader PROMs into 64x16 format in
memory, and patch in the I/O select code while it is doing it.
----
The same 1K parts are used interchangeably for loader roms or microcode on the FAB. They
are the same chip regardless of if they contain loader code or microcode.
J
4:53 p.m.
On Sun, 6 Sep 2015, Jay West wrote:
Here's a non-exhaustive but useful list of
compatible parts for each:
4K parts
Signetics N82S141
Harris 7641
MMI 6341
You can add National 74S474 to this group. I've tried it, and they
work.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
10:39 p.m.
On Sunday, September 6, 2015 at 13:41, Jay West wrote:
Here's a non-exhaustive but useful list of
compatible parts for each:
[...]
4K parts
Signetics N82S141
Harris 7641
MMI 6341
Some additional part numbers:
- AMD Am27S31
- National DM87S474
8K parts
Signetics N82S181
Harris 7681
MMI 6381
Also:
- AMD Am27S181
- National DM87S181
-- Dave
3242
days inactive
3243
days old
14 comments
10 participants
participants (10)
-
aek＠bitsavers.org -
alexandre.tabajara＠gmail.com -
dkelvey＠hotmail.com -
elson＠pico-systems.com -
glen.slick＠gmail.com -
jdbryan＠acm.org -
jrr＠flippers.com -
jwest＠classiccmp.org -
mloewen＠cpumagic.scol.pa.us -
scaron＠umich.edu