16 Jun
2009
16 Jun
'09
4:42 p.m.
On 16 Jun 2009 at 0:42, Scanning wrote:
You are correct sir. I had forgotten about the dark
ages of 4000
Series 10 Volt Bulk CMOS. It's all coming back to me now, the night
sweats and the flashbacks.... I think I even have a 10 Volt CDP1802
lurking in a drawer somewhere...
I still have my "Solid State Scientific" reference manual for 4000
series CMOS--a slim booklet. Data for each device is displayed in 3
rows--for Vdd of +5, +10 and +15 volts. Performance at +5 was
ridiculous; propogation delays in excess of a microsecond for some
parts. Performance at +10 and +15 was *much* better. I conculded at
the time that, aside from the analogue switches, the family was
probably not ready for prime-time deployment at +5v. Considering the
speed and very low voltages that modern CMOS enjoys, the evolution
has been nothing less than remarkable.
I've been looking for another 10 Volt CMOS EPROM
without any luck.
Looks like building a programmer for the parts he has might be the
best approach. If we knew the source for the EPROM data we might be
able to kludge up a Willem ( sp? ) programmer to program a part....
It's probably possible, but it's prudent to count on ruining at least
one part in the process of getting the programming algorithm right.
Without a supply of sacrificial animals, I don't think I'd want to
take this one on.
Perhaps there are some fuse-link programmable CMOS ROMs that could be
adapted, but most "modern" CMOS memories are rated for +7 volts,
tops.
--Chuck