16 Feb
2016
16 Feb
'16
12:04 a.m.
On 02/15/2016 11:25 PM, Eric Smith wrote:
On Mon, Feb 15, 2016 at 11:31 PM, John Robertson
<jrr at flippers.com> wrote:
Does it share the same pinout as the 1702 MOS Eprom? I can read and
program those EPROMs in my shop. The 1705 has a Vcc of +5, and a Vdd of
-9 to a maximum of -20VDC, it is a 24 pin device though.
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
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"Old pinballers never die, they just flip out"
Rick, if you want to archive these PROMs (highly
recommended) you should be
able to find a Data I/O 29B and get one of the programming packs that
supports NS chips. I may have such a combination in my collection, but that
PROM is not listed in my DATA I/O library of readable parts.
They're not
PROMs, they are masked ROMs, and there is *NO* equivalent
PROM, so it's unlikely that there's any support for reading them on
any PROM programmer.
Part of the
problem with the early PROMs is they needed a Sync or Clock signal to be
able to be read.
The MM4221/5221 is fully static, so it doesn't have that
particular problem.
It's PMOS, and needs +5V and -12V supplies. The outputs are
TTL-compatible, but the inputs technically are not, due to Vih min of
3.0V. Could be driven by TTL with a pullup resistor, or by CMOS.