5 Feb
2015
5 Feb
'15
1:49 p.m.
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
Thanks.
5 Feb
5 Feb
2:43 p.m.
On Thu, Feb 5, 2015 at 10:49 AM, Roe Peterson <roeapeterson at gmail.com> wrote:
I want to update the EPROMs on my 11/23+, which
currently has 2716s. I'm going to need 64k chips, and I understand 2764s won't
work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
MCM68766
3:01 p.m.
On 02/05/2015 11:43 AM, Glen Slick wrote:
On Thu, Feb 5, 2015 at 10:49 AM, Roe Peterson
<roeapeterson at gmail.com> wrote:
There's also the '68765--a crap-shoot as far as which is easier to find.
--Chuck
I want to update the EPROMs on my 11/23+, which
currently has 2716s. I'm going to need 64k chips, and I understand 2764s won't
work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
MCM68766
3:15 p.m.
On Feb 5, 2015, at 2:01 PM, Chuck Guzis <cclist at
sydex.com> wrote:
How about MC68764L?
On 02/05/2015 11:43 AM, Glen Slick wrote:
There's also the '68765--a crap-shoot as far as which is easier to find. On Thu, Feb 5, 2015 at 10:49 AM, Roe Peterson
<roeapeterson at gmail.com> wrote:
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
MCM68766
--Chuck
3:30 p.m.
On 02/05/2015 12:15 PM, Roe Peterson wrote:
If it's fast enough, probably. The 764 did start the Moto line of 64Kb
of 24-pin EPROMs. Doubtless one could also probably work up an SMT
EEPROM as a plug-in module.
--Chuck
On Feb 5, 2015, at 2:01 PM, Chuck Guzis
<cclist at sydex.com> wrote:
How about MC68764L? On 02/05/2015 11:43 AM, Glen Slick wrote:
There's also the '68765--a crap-shoot as far as which is easier to find. On Thu, Feb 5, 2015 at 10:49 AM, Roe Peterson
<roeapeterson at gmail.com> wrote:
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
MCM68766
3:56 p.m.
On Feb 5, 2015, at 2:30 PM, Chuck Guzis <cclist at
sydex.com> wrote:
They are rated at 450ns, how fast is a 2716?
On 02/05/2015 12:15 PM, Roe Peterson wrote:
If it's fast enough, probably. The 764 did start the Moto line of 64Kb of 24-pin
EPROMs. Doubtless one could also probably work up an SMT EEPROM as a plug-in module.
also the '68765--a crap-shoot as far as
which is easier to find.
How about MC68764L?
--Chuck
6 Feb
6 Feb
1:29 p.m.
On Feb 5, 2015, at 2:01 PM, Chuck Guzis <cclist at sydex.com> wrote:
> On 02/05/2015 11:43 AM, Glen Slick wrote:
>> On Thu, Feb 5, 2015 at 10:49 AM, Roe Peterson <roeapeterson at gmail.com>
wrote:
>> I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm
going to need 64k chips, and I understand 2764s won't work on this board.
>>
>> What are my replacement options? I have a fairly capable programmer, it can
probably handle anything with 64k capacity.
>
> MCM68766
I found 10 of these on eBay for 5 bucks apiece, guaranteed erased and tested, with
warranty.
Thanks, everyone.
There's also the '68765--a crap-shoot as far as which is easier to find.
--Chuck
5:11 a.m.
On 2015-02-05 19:49, Roe Peterson wrote:
I want to update the EPROMs on my 11/23+, which
currently has 2716s. I'm going to need 64k chips, and I understand 2764s won't
work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
??? I don't get it.
64K chips? The 11/23 currently uses the 2716, which is what? 2K (bytes)?
I doubt there are any more address lines going to that chip in the first
place, and second, the memory is mapped in the I/O space which have a
total of 8K, and that should cover not only the boot rom, but also all
CSRs of all devices you have in the machine. A 64K chip is going to be
totally meaningless.
So why are you looking for a 64K chip? (27512 I would assume that would
be...)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
6:35 a.m.
On 06/02/2015 10:11, Johnny Billquist wrote:
On 2015-02-05 19:49, Roe Peterson wrote:
> I want to update the EPROMs on my 11/23+, which currently has 2716s.
> I'm going to need 64k chips, and I understand 2764s won't work on this
> board.
Correct, wrong physical size. DEC used Motorola MCM68766.
64K chips? The 11/23 currently uses the 2716, which is
what? 2K (bytes)?
I doubt there are any more address lines going to that chip in the first
place, and second, the memory is mapped in the I/O space which have a
total of 8K, and that should cover not only the boot rom, but also all
CSRs of all devices you have in the machine. A 64K chip is going to be
totally meaningless.
Not so. Only the earliest release 11/23+ (KDF11-BA) used 2KB firmware;
all the later versions (there are at least six) used 8KB and had more
functionality. The M8189 board is designed to take either. In both
cases, the ROM is paged exactly as it is in a BDV11, and only 256 bytes
are visible at a time. J22/J23/J24 are the links used to configure the
sockets, and you'll find the settings on page 2-8 of the KDF11-BA Users
Guide. Seven address bits to the ROMs come from the bus, six are
provided by paging registers on the CPU board, for a total of 13 address
bits, or 8KB address space.
So why are you looking for a 64K chip? (27512 I would
assume that would
be...)
2764. He meant 64K bits.
--
Pete
Pete Turnbull
6:55 a.m.
On 2015-02-06 12:35, Pete Turnbull wrote:
That was a different story, yes. :-)
Johnny
On 06/02/2015 10:11, Johnny Billquist wrote:
Ok. I wasn't aware that the 11/23 had a page selection mechanism for the
boot rom.
On 2015-02-05 19:49, Roe Peterson wrote:
> I want to update the EPROMs on my 11/23+, which currently has 2716s.
> I'm going to need 64k chips, and I understand 2764s won't work on this
> board.
Correct, wrong physical size. DEC used Motorola MCM68766.
64K chips? The 11/23 currently uses the 2716,
which is what? 2K (bytes)?
I doubt there are any more address lines going to that chip in the first
place, and second, the memory is mapped in the I/O space which have a
total of 8K, and that should cover not only the boot rom, but also all
CSRs of all devices you have in the machine. A 64K chip is going to be
totally meaningless.
Not so. Only the earliest release 11/23+ (KDF11-BA) used 2KB firmware;
all the later versions (there are at least six) used 8KB and had more
functionality. The M8189 board is designed to take either. In both
cases, the ROM is paged exactly as it is in a BDV11, and only 256 bytes
are visible at a time. J22/J23/J24 are the links used to configure the
sockets, and you'll find the settings on page 2-8 of the KDF11-BA Users
Guide. Seven address bits to the ROMs come from the bus, six are
provided by paging registers on the CPU board, for a total of 13 address
bits, or 8KB address space. So why are you
looking for a 64K chip? (27512 I would assume that would
be...)
2764. He meant 64K bits.
6:41 a.m.
On Feb 6, 2015, at 4:11 AM, Johnny Billquist <bqt
at update.uu.se> wrote:
2716 = 16k bits = 2kbytes X 8 bits
2764 = 64k bits = 8kbytes X 8 bits
The latest rom images for the 11/23+ require 8kbyte chips.
On 2015-02-05 19:49, Roe Peterson wrote:
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
??? I don't get it.
64K chips? The 11/23 currently uses the 2716, which is what? 2K (bytes)? I doubt there
are any more address lines going to that chip in the first place, and second, the memory
is mapped in the I/O space which have a total of 8K, and that should cover not only the
boot rom, but also all CSRs of all devices you have in the machine. A 64K chip is going to
be totally meaningless.
So why are you looking for a 64K chip? (27512 I would assume that would be...)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
6:53 a.m.
On 2015-02-06 12:41, Roe Peterson wrote:
Ah, so 2764, not 64K bytes... Oh well... :-)
When did people start counting memory sizes in bits???
Johnny
On Feb 6, 2015, at 4:11 AM, Johnny Billquist
<bqt at update.uu.se> wrote:
2716 = 16k bits = 2kbytes X 8 bits
2764 = 64k bits = 8kbytes X 8 bits
The latest rom images for the 11/23+ require 8kbyte chips. On 2015-02-05 19:49, Roe Peterson wrote:
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
??? I don't get it.
64K chips? The 11/23 currently uses the 2716, which is what? 2K (bytes)? I doubt there
are any more address lines going to that chip in the first place, and second, the memory
is mapped in the I/O space which have a total of 8K, and that should cover not only the
boot rom, but also all CSRs of all devices you have in the machine. A 64K chip is going to
be totally meaningless.
So why are you looking for a 64K chip? (27512 I would assume that would be...) 
4:16 p.m.
On 2015-Feb-06, at 3:53 AM, Johnny Billquist wrote:
On 2015-02-06 12:41, Roe Peterson wrote:
Ah, so 2764, not 64K bytes... Oh well... :-)
When did people start counting memory sizes in bits???
Oh, at least as early as the mid-70s, with the 2708 (1KByte).
Yes, I too wish they had used bytes for eprom sizes.
On Feb 6, 2015, at 4:11 AM, Johnny Billquist
<bqt at update.uu.se> wrote:
2716 = 16k bits = 2kbytes X 8 bits
2764 = 64k bits = 8kbytes X 8 bits
The latest rom images for the 11/23+ require 8kbyte chips. On 2015-02-05 19:49, Roe Peterson wrote:
I want to update the EPROMs on my 11/23+, which currently has 2716s. I'm going to
need 64k chips, and I understand 2764s won't work on this board.
What are my replacement options? I have a fairly capable programmer, it can probably
handle anything with 64k capacity.
??? I don't get it.
64K chips? The 11/23 currently uses the 2716, which is what? 2K (bytes)? I doubt there
are any more address lines going to that chip in the first place, and second, the memory
is mapped in the I/O space which have a total of 8K, and that should cover not only the
boot rom, but also all CSRs of all devices you have in the machine. A 64K chip is going to
be totally meaningless.
So why are you looking for a 64K chip? (27512 I would assume that would be...)
6:13 p.m.
On Feb 6, 2015, machine. A 64K chip is going to be
totally meaningless.
>>>
>>> So why are you looking for a 64K chip? (27512 I would assume that would
be...)
>>
>> 2716 = 16k bits = 2kbytes X 8 bits
>> 2764 = 64k bits = 8kbytes X 8 bits
>>
>> The latest rom images for the 11/23+ require 8kbyte chips.
>
> Ah, so 2764, not 64K bytes... Oh well... :-)
> When did people start counting memory sizes in bits???
ROMs are like bandwidth on the Internet, sold in bits (kbits, megabits) ,consumed in
bytes.
Oh, at least as early as the mid-70s, with the 2708 (1KByte).
Yes, I too wish they had used bytes for eprom sizes.
3450
days inactive
3451
days old
13 comments
6 participants
participants (6)
-
bqt＠update.uu.se -
cclist＠sydex.com -
glen.slick＠gmail.com -
hilpert＠cs.ubc.ca -
pete＠dunnington.plus.com -
roeapeterson＠gmail.com