Dear Kai,
Sometimes back availability of this supposed to be champion at89s2051 (and I say why not at89s4051 then) was discussed at international level in this forum ;Mr. Erik Malund who kindly tried to remind me about this during my remote control project, was also participated;and to my great astonishedment, it transpired from the same thread that nobody seem to where it is available.
Or may be I am wrong.....but fact is ...I have been dying to receive a strip of at89s2051/4051 against Indian Rupee payment,preferably at my doorstep,presuming I have to pay @ double...... er how much is @ triple?, for the last few years.
The whole point is ATMEL china is full swing with AT89C2051 but the enormus capacity of the plant is more than the (local) demand;hence the price is falling to the annoyance of ATMEL headquarters who in turn have developed these ATS2051/4051 but yet to license to chinese counterpart.I am experienced to predict that this situation will not last long (THE GREAT ELECTRONICS OBSOLESENCE) but meanwhile thought of taking advantage.
So Kai,we are back to AT89C2051/4051 and kindly start repeating whatever you advised regarding funny/undocumented behaviour of their Reset/Vpp Pin no 1.
Kindly suggest repeatable situation before advising reset supervisor chip
for this low cost project for this part of the subcontinent.I unfortunately cannot repeat failure for using 8k2_10µF.
I appreciate that this peoject proposal lacks illaboration.But since JW has cleared it I repeat with change in language.
I want to build a 4 X AA cells battery operated portable(hip pocket size) device featuring a 16x2 alphanumeric LCD,sharing resources with a set of tactile switches below,and two ZIF sockets,40 and 20,
and what else?may be a few dual leds; to program AT89C2051,either from Host AT89S52/8252's RAM or EEPROM,THE SAME HEX ALWAYS,WITHOUT PC.
One may ask why two ZIF sockets then?
That is in developement/higher cost models .I am to confirm my understanding that in 2051 you always start at address 00 to read.weite or erase which is not so in case with AT89C51/52.
Regards
A.S.Rudra,
emails are welcome through Craig - hope my account's alright.
P.S.This is bound to use a lot of 8052.com 's SBCMON HARDWARE AND SOFTWARE features since I think Craig has permitted that.Infact right now I am in the design tension of using 74LS373(as per easy or 74HC573 as per sbcmon) and wondering why 74LS573 is not available with my regular supplier.
Another good news is locating a cheap,local, double layer copper clad source.I will no more design single layer but who knows.