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Suitable SRAM Replacement


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8 hours ago, F.G. Kaal said:

The interrupt is not important on the IDE card.

 

One of the first things that the INIT routine of the IDE DSR does is to disable the interrupt of the clock chip.

One of the things I noticed in the very beginning of the IDE card is that sometimes when the DSR is not loaded yet in the RAM, and thus the RTC interrupt is not disabled, that the system hangs because the RTC had generated an interrupt after power on. That is why I disconnected the interrupt pin. Al is fine after the DSR is loaded.

 

Fred if I snipped the interrupt line right here would that be the best location? Or should I do it closer to the BQ4852/42 pins? Thanks 

Ide card interrupt snip.jpg

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On 9/29/2023 at 3:46 AM, RickyDean said:

Fred if I snipped the interrupt line right here would that be the best location? Or should I do it closer to the BQ4852/42 pins? Thanks 

Ide card interrupt snip.jpg

That seems to be the correct location. Then it doesn't matter what clock chip is installed ... the interrupt is disabled for sure.

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  • 5 months later...
On 9/27/2023 at 11:28 PM, RickyDean said:

       Wow, I keep resurrecting these old threads. On the IDE card, as discussed by @Swim there is the BQ4852 that has 512k Sram on board, so if you use it you don't need the 512k sram chip. It has 36 pins two of which are not connected, one that is a programmable interrupt, and then it has a separate  Microprocessor reset, apart from A18 address line.

       On the other hand I have in my procession about 20 or so Dallas DS1251Y timekeeper SRAM 512 x 8 that is 32 pins. It does not have a programmable interrupt, and the Microprocessor reset pin is shared with A18 address. It seems like I can build a small board here and use the Dallas chip in place of the BenchMarq chip. Is the interrupt important here on the IDE card?

       The 32 pin BenchMarq BQ4842Y that can be used on the IDE card doesn't share quite the same pin footprint. I think it would be easier to fit the Dallas in the 36 pin slot. The interrupt is probably used for CRU purposes according to the schematics, so could that be done another way? What do y'all think? I'm just wanting to see if I can use what I have on hand.

 

  

bq4852Y.jpg

Dallas DS1251Y.jpgimage.thumb.jpeg.9a88a45e1a694dca34682e5c43ff4118.jpeg

bq4842Y.jpg

I' wanting to purchase some of these BQ4852 Cloc/Sram chips from Rochester Electronics for the IDE cards. There is a minium purchase requirement of 250.00. Is anyone else interested in buying a couple of these IC's at $50.88 + shipping cost if any, before I make a firm decision? PM me if interested.

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  • 2 months later...

Well I pulled the plug and made these purchases today. We'll see what we get.

 

HDC9234P
2 $13.0936/item $0.00
$26.19
BQ4852YMC-85
5 $50.0882/item $0.00
$250.44
HDC9234LSH-P
2 $13.4919/item $0.00
$26.98
HDC9234GNDLSHP
2 $13.4919/item $0.00
$26.98
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  • 2 weeks later...

Well Rochester sent me chips:

 

I received LSIC6603 LONGSHINE Ic's instead of HDC9234GNDLSHP's andHDC9234LSH-P. Can anyone give me datasheet info for this particular chip, I've googled, but can't find anything about it directly?

I recieved SMC HDC9234 as HDC9234P's

I received the BQ4852YMC-85's, but they sure look like China procured chips to me. Does anyone know of a clock chip that could have been used as the base for this battery backed chip?

 

 

 

20240624_170122.jpg

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4 minutes ago, RickyDean said:

Well I'm gettign close to the Longshine IC. Here's a Longshine product that uses SMC IC's on it.

longshine mfm controller.jpg

As far as I know they only made mfm type Isa controllers I suspect your ic is just a rebranded hdc9234 with their logo and markings on it.

 

Dig around some Russian forums they seem to have more information on longshine stuff.

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14 minutes ago, Gary from OPA said:

As far as I know they only made mfm type Isa controllers I suspect your ic is just a rebranded hdc9234 with their logo and markings on it.

 

Dig around some Russian forums they seem to have more information on longshine stuff.

That's what I'm assuming as a possibility. Getting a working PEB box soon and will probably test one in one of my HFDC's. Just hate the possibility of killing the gate array;(

Found this one too. It uses the 9234 IC

 

LCS-6620TX Rev 2 ISA HARD DISK-FLOPPY CONTROLLER MFM - ST506-412.webp

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7 minutes ago, RickyDean said:

That's what I'm assuming as a possibility. Getting a working PEB box soon and will probably test one in one of my HFDC's. Just hate the possibiltiy of killing the gate array;(

Could try building a simple test circuit for the IC just to hook up power and ground and see if you can read and write to the internal registers like it was hdc9234 that would confirm it is one.

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31 minutes ago, Gary from OPA said:

Could try building a simple test circuit for the IC just to hook up power and ground and see if you can read and write to the internal registers like it was hdc9234 that would confirm it is one.

I have submitted a request to the company for possible documentation. Longshine is a Deutsch(German) company

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41 minutes ago, RickyDean said:

I have submitted a request to the company for possible documentation. Longshine is a Deutsch(German) company

Actually, Longshine is Taiwanese, based on everything I found when I went hunting on Monday. They have subsidiaries in several countries (Germany is one), but the main offices are in Taiwan. None of the usual suspects have datasheets for them though, which is actually a bit odd. If Rochester sent them as a suitable sub for the 9234, they may have the datasheet (or at least a valid cross-reference chart showing that they are really 9234s labeled differently). Rochester will usually answer such questions, and will often have datasheets for the odd substitute chips they have--mainly because when the OEM passes the rights to them, they get everything the manufacturer had for that chip, to include all chips in stock.

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On 6/24/2024 at 7:09 PM, RickyDean said:

The BQ4852YMC-85 chip

20240624_190440.jpg

This chip doesn't have the hallmarks of a Chinese sourced chip.

 

Look carefully at the top of the chip. The surface is mildly pebbled (with actual small variations in height) and blends in to the sides. Chinese sourced chips will have had the top slightly shaved down (it will appear slightly pebbled from the inner fill material but the color will be off from the color on the sides--and the top will be smooth or slightly striated.

 

Rochester likely got these as surplus from TI or made their own new ones.

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1 hour ago, Ksarul said:

Actually, Longshine is Taiwanese, based on everything I found when I went hunting on Monday. They have subsidiaries in several countries (Germany is one), but the main offices are in Taiwan. None of the usual suspects have datasheets for them though, which is actually a bit odd. If Rochester sent them as a suitable sub for the 9234, they may have the datasheet (or at least a valid cross-reference chart showing that they are really 9234s labeled differently). Rochester will usually answer such questions, and will often have datasheets for the odd substitute chips they have--mainly because when the OEM passes the rights to them, they get everything the manufacturer had for that chip, to include all chips in stock.

The one in Germany seems to be only one using the same logo as on the chip itself.

 

https://www.linkedin.com/company/longshine-technologie-gmbh

Screenshot_20240626-015603.png

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8 hours ago, Ksarul said:

This chip doesn't have the hallmarks of a Chinese sourced chip.

 

Look carefully at the top of the chip. The surface is mildly pebbled (with actual small variations in height) and blends in to the sides. Chinese sourced chips will have had the top slightly shaved down (it will appear slightly pebbled from the inner fill material but the color will be off from the color on the sides--and the top will be smooth or slightly striated.

 

Rochester likely got these as surplus from TI or made their own new ones.

Ok, they just looked a little faked to me, but I understand what your saying. As for the 6603's I give it a day or two to see if I receive a a response from LSI before I check back with Rochester. Thanks for the clarification.

 

Well as I looked at my email after this I see that LSI responded to me:

"Hello Ricky, 

yes it is the correct company part, but the old mother company in Taiwan is closed, but I will try to get some information,

with best regards

 

Thomas Grashoff

Executive Vice President"

 

So that is what I have so far.

Edited by RickyDean
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  • 4 weeks later...

Well I nudged them a little bit yesterday and they responded.

"Hello, sorry we found no information, but must be a MFM controller ship.

 

with best regards

 

Thomas Grashoff

Executive Vice President

 

Longshine Technologie GmbH

An der Strusbek 9

D-22926 Ahrensburg"

 

I sent Mr. Grashoff a thank you and I will try this out, probably on a Longshine card that uses the HDC9234 first, to see if it functions the same before attempting to use it in a HFDC. Sure don't want to blow the gate array.

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