22 Oct
2004
22 Oct
'04
8:15 a.m.
From: ard(a)p850ug1.demon.co.uk
Hi Tony
I think you are right about the 23xxx being mask versions.
The problem with the newer EPROM parts is that they do not
require pulsing of the programming voltage. Many programmers
simply leave the programming voltage high while reading or
verifying. This is real bad for mask parts. Also, most mask
parts use the programming voltage pin as another select.
This means that it may need to be in the opposite state that,
even a programmer that allows setting of the program voltage,
may not be in the right state to read.
Also, I think this fellow is off the list and doesn't realize
that he is talking to a list. I suspect he is missing our
conversations related to his issue.
Dwight
Hi,
I know very little about electronics and eproms so this question might be
really easy. I would like to know what the difference is between a 23512
eprom and a 27512 and if there are any differences if its possible to make
I thought the 23512 was the mask-programmed part (not an EPROM), and is
otherwise the same device. You should be able to read it (unless your
programmer tries to be clever and read the manufacturer's ID word, etc).
-tony
22 Oct
22 Oct
10:59 a.m.
On Fri, Oct 22, 2004 at 10:15:29AM -0700, Dwight K. Elvey wrote:
Hi Tony
I think you are right about the 23xxx being mask versions.
That is my experience with Commodore ROMs - 23xxx are mask-
programmable, and 25xx and 27xx are various varieties of
EPROMs (sometimes pin-compatible, frequently not).
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 22-Oct-2004 19:50 Z
South Pole Station
PSC 468 Box 400 Temp -54.1 F (-47.9 C) Windchill -67.3 F (-55.2 C)
APO AP 96598 Wind 2.4 kts Grid 064 Barometer 672.9 mb (10896. ft)
Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html
11:33 a.m.
Dwight, not missing the discussion ;-)
At 19:15 22-10-2004, you wrote:
From:
ard(a)p850ug1.demon.co.uk
>
> Hi,
>
> I know very little about electronics and eproms so this question might be
> really easy. I would like to know what the difference is between a 23512
> eprom and a 27512 and if there are any differences if its possible to
make
I thought the 23512 was the mask-programmed part (not an EPROM), and is
otherwise the same device. You should be able to read it (unless your
programmer tries to be clever and read the manufacturer's ID word, etc).
-tony
Hi Tony
I think you are right about the 23xxx being mask versions.
The problem with the newer EPROM parts is that they do not
require pulsing of the programming voltage. Many programmers
simply leave the programming voltage high while reading or
verifying. This is real bad for mask parts. Also, most mask
parts use the programming voltage pin as another select.
This means that it may need to be in the opposite state that,
even a programmer that allows setting of the program voltage,
may not be in the right state to read.
Also, I think this fellow is off the list and doesn't realize
that he is talking to a list. I suspect he is missing our
conversations related to his issue.
Dwight
7247
days inactive
7247
days old
2 comments
3 participants
participants (3)
-
birs23＠zeelandnet.nl -
dickset＠amanda.spole.gov -
dwight.elvey＠amd.com