Where can i find the PT2399 Chip for the rebot2 delay?
-J
http://www.smallbearelec.com
where else?!
"-)
Quote from: MarkBhttp://www.smallbearelec.com
where else?!
"-)
from asking the company for a free sample via email or written leter via snail mail
princeton never replied to me, when asking for quotes...
Quote from: puretubeprinceton never replied to me, when asking for quotes...
wow i am shocked i got one in the mail a little over a week after i emailed them, of course i didint' get a reply from them but i got a chip so i was happy.
Taiwan doesn`t seem to like me... :cry:
whereas CHINA sure does !!! :D
Where else?
Me. I bought a lot of them and could sellthem to you for less than SB.
-Colin
well, I tried the company in Taiwan directly - not an American office -
don`t wanna pay shipping fare-ast to US to europe...
(and don`t wanna bust SB`s or EA`s supply...)
same occurence with the Taiwanese manufacturer of those DC-jacks...
if one of you could link me (PM) to the address you got the stuff from,
I could check whether it`s better to try connecting them via US,
or try my newly found Chinese source for re-issue M*ts*bishi clones...
(yes, Mark/Peter: incl. those with external RAM :wink: ).
ps: I don`t intend to make a business re-selling them...
PureTube, e-mail me if you want the stateside distributor I buy them in semi bulk from.
-Colni
Colin: thanx for offering help: you got mail
8)
Isn't there a Shanghai office for those people making the Mitsubishi clone BBDs? If so, I might be able to help out - I have a previously close ;) contact in Shanghai who is Chinese, and she is kind and I'm sure wouldn't help out with a little translation or possibly even phone contact. PM me for more info....
Cheers
Mike
thank you for the offer, Mike:
Shanghai* is not a problem at all - quite the contrary.... :wink:
but trying to contact several Taiwanese factories for comparison/samples/quotes proved to be impossible for me...
*(Mitsu- and Matsu-/Pana-clones)
Cool .... yes, the Chinese do appear to have their act together pretty nicely when selling stuff to the outside world. They'll be even more of an economic superpower before long. Watch out Westerners!!!!!
As for Taiwan .... sorry, no ex-g/fs there .... :P
Mike
Colin: thank you for helping out! 8)
I`ll try to get in contact with`em, and see what they got to offer...
There`s some experimenting in my head/on breadboard for several
different gadgets
- ones that call for "all in" chips like the 2399, and others that I`d rather
have direct access to the memory... -
(Vsat (RESPECT!) seems to row a similar boat:
http://diystompboxes.com/sboxforum/viewtopic.php?t=25168&postdays=0&postorder=asc&start=30)
and there was a thread a while ago, pondering over DRAMS for these kinda purposes...
Quote from: puretube.....or try my newly found Chinese source for re-issue M*ts*bishi clones...
(yes, Mark/Peter: incl. those with external RAM :wink: ).
:shock: :D 8)
VERY interesting! 8) Please do tell. :D (by PM if necessary)
Can you buy just one rail?, and are any of the parts SMD?
Thanks!!!! :D
I've got the DRAM thing all figured out to extend a PT2395 to 25.6 seconds (or 51.2, or....) using surplus computer memory or new manufacture DRAM. :mrgreen: Now I just need to get a PT2395 to test it. It
should work find provided that PT chip doesn't use a read-modify-write access methodology. If so, I'll need to make a small adjustment.
I've been toying with discrete first order delta modulators for delay, but the adaptive delta mo/dem in the PT2395 wins out almost by default.
this was the DRAM thread:
http://diystompboxes.com/sboxforum/viewtopic.php?t=22592&highlight=dram
Peter (mikeB): my source "forgot" to send me the 200 chips
last year (during the SARS epidemy...) in another big bulk order,
and I didn`t wanna pay for extra-delivery shipping...
Quite soon I`m gonna place a new large order, there.
(especially since I could lay
hands on a huge pile of Infineon 411000s, lately).
I`d sure be able to spare some to you...
Can`t find the data-sheets in my mess at the moment, but IIRC,
those are in 36, 38, or 40 DIP package (not SMD).....
ps: afaik, the PT2395 is discontinued, as well as the Holtek workalikes,
so these are none of my interest for the future;
- otherwise I woulda just ordered a couple from Smallbear -
if those chips work out well, I`ll give Steve Daniels a wink, so he might
get hold of them...
btw: it`s a pity, M*ts*bishi`s app.-notes have disappeared from the web...
EDIT/OOOPS: PT2395 seems not discontinued, though it had looked like that last year, on their old website:
just been there again, and found it is still listed
-sorry for the disturbance, folks-
:oops: :oops: :oops:
well, the "all in" chip is a 14pin DIP, built-in RAM;
"M65844P compatible";
150ms @ 220kHz (external R/C clock)
(seems similar to the PT2399...)
the other is a 36pin DIP, external 64k or 256k DRAM;
"M50915P compatible";
3 delaytime modes: 100/150/200ms switchable @ 4MHz external X-tal.
A0 to A7, W, RAS, CAS, DI, DO and RESET on discrete pins,
while the mode-select seems to be 3 different counter-outputs, switchable to the reset-pin.
(I`m not sure if M50915P is a Chinese typo...)
Peter: for just trying one or two PT2395s, order from Smallbear: faster than me! (guess he got enough NOS for the DIY-scene ?)
But for experimental reasons, I`d send you 2 or 4 of the latter ones,
to see if they are "extended memorable", too.
-before I start going thru that whole R&D thing myself...-
-will take some time, though-
Arrgh, the PT2395 is discontinued!!!!!!????? :(
None of the 41256s on their way to me arrived.
(sigh) the sad story of someone with little money to pursue an idea .... maybe time to think about a bank loan for the biz ....
Mike
PS All I want is *some* IC that can be used with (moderately) easily purchasable external RAM, price not so important as I'll only ever make anything a few at a time....
Mike
sorry for misleading info:
PT2395 is not obsolete! :D :D :D
just been to the new website of princeton, and it is still there!!!
(whilst I had in memory it had disappeared from there last year, when I tried to get some info from them...)
this means Smallbear will be able to stock up and ship any time...
SORRY, folks - didn`t wanna shock you... :cry: :oops:
that "new source" 36pin chip for external RAM looks from it`s data-sheet (which btw. isn`t very informative...) exactly like the PT2395 minus the lacking A8;
they write "M50915P compatible", but very probable mean:
"M50195P compatible";
anyone have some datasheet/application notes for that (old) Mitsubishi-chip???
finally have managed to find a direct import for the Princeton PT2395
- looks like even cheaper than those Chinese M*ts*bishi clones -
Peter: do you just use a 4013 to provide an A9/A10 adress and for "delaying" the reset accordingly?
Quote from: puretubePeter: do you just use a 4013 to provide an A9/A10 adress and for "delaying" the reset accordingly?
Good news on the distributer! :D
My "scheme" is to increase the buffer by adding *width* and not *height* ;).
I do have a diagram drawn up that uses a pair of flip-flops to create a pseudo A9 from a latched and divided A8, but there is no easy way to know when the PT2395 is trying to source the row or the column so the best I could come up with would utilize only 1/2 of a 1 meg chip. This diagram also assumes that the PT2395 is refreshing at least 2X the minimum speed required by the memory. I still need to toss a chip on my logic analyzer to see the refresh method. If it uses self-refresh, that last speed requirement is no longer an issue.
I look at the PT2395 and weep because pin 40 is N/C and my mind thinks it should have been A9. ;) Oh well.... at least there are plenty of 256k*4 chips out there. :)
What would the purpose be of delaying the reset? (is that just for clearing the whole DRAM at power-up?)
PS: Ton, I'll get back to you RE that PM ASAIC, or ASAP. :o
I thought "somebody" got to tell the address-counter, when to start at 0,
and how far to count (64k or 256k, for extended memory:512k or 1M)
and then reset to O and start counting all over.
The Holtek 8955 had an extra pin to select the kind of RAM used (64k or 256k), which was nothing other than a logic select (Hi or Lo) for "where" to reset the counter.
(This Holtek was/is(?) also interesting in the fact, that it had 2 clock OSCs: one for audio-sampling, and an independant one for delay-time!
Dunno if it even had SCFs linked to the audio-clock...).
Anyway: I`m not sure, how this reset is done in the PT2395:
there is a mysterious "Delay-select" box in the top-right corner of the data-sheet, which detects the levels on 3 "select" pins, to control the central "main control logic" block, which in turn is responsible for counting and so on...
It`s a little unclear to me, "how" the chip "knows", if it addresses a 64k or a 256k RAM (or an 512k or even 1M)concerning address-counter reset;
for those larger RAMs, the reset-the-counter-pulse should occur "later"
(i.e.: after 512/1024k), which I referred to as "delayed"...
Do I mis-interpret something?
edit: oops: just found out, the PT2395 in fact does have that memory-select pin(20), too...
As far as I can tell, the reset line is only used to store a "blank" pattern in the buffer to eliminate a loud burst of static at power-up. It may also work by reducing the span of the "adaptive" part of the adaptive delta demodulator to zero. That would be a clean way to do things. :D
I would not be surprised at all if the address counter is left to be random, in fact it may be a LFSR based counter where the counting sequence is nothing like 1,2,3,4,5....
I'm sure the address counters just roll-over to zero so no reset is required for them. Selecting between 64K and 256K is simply a matter of running the A8 output through an AND gate with the 256K enable signal and then selecting the column address from either A9-A17 or from A8-A15.
As the address counter is only 18 bits wide, the PT2395 has no ideas about address spaces that are larger than 256K and therefore no idea how to refresh larger arrays if it uses an internal refresh counter.
noticed earlier today, that I need to refresh my memory on this subject a little...
:wink:
to expand the memory of the pt2395 you have to parallel the ram chips and use the cas signal as a chip selector,driven by a counter...
...which would be "increasing the width" for e.g. a 256k*4, like Peter said, right?
Interesting... :D I never thought of using a counter to select different chips.
My approach uses a single memory chip, a latch on the data lines, and one other (fairly) common 74HC or 74HCT part. :D