The road to "Dual Celeron" with
Socket 370 to Slot1 Converter card

Japanese

A-MAX Socket370 to Slot1 conversion card

Until recently, we had no use of those Socket 370 PPGA Celerons since those are primary targeted for the dedicated motherboard, however we are starting to to see (and of course) to be able to purchase Socket 370 to Slot 1 conversion cards here in Japan.

A-MAX conversion card

Here is the Socket370 to Slot1 conversion card from A-Max Technology which I've got. I believe this is the first one out in Akihabara.

PPGA Celeron

Since I've got hold of the conversion card, I went out to buy the PPGA Celeron 300A retail package (SL35Q) Stepping ID665. No problem with running at FSB 100MHz with normal 2.0V, however it will need some 'kick' i.e. increase in core the voltage if it is to be run at 504MHz. If you get lucky, it may run at 504MHz with normal voltage.

PPGA Celeron300A(SL35Q)

Dual operation?

Then the all important 'Dual operation'...NG with no modification to the adapter. One of the reason is, of course, BR1# is reserved according to the Celeron's data sheet. In addtion, A-MAX's Socket370 to Slot1 conversion card has B75 pin/contact as N/C, making it even more difficult.

Considering the fact that we just don't know where BR1# pin is located on the PPGA package, and we don't know whether this pin really EXIST or not, we just have to give it up on making them dual operational for the time being..

...well, that was my feeling. HOWEVER, I've got GREAT news form Mr. Christoper Kuperman who lives in Australia that he'd succeeded in making them dual operational with using MSI's converter board, MSI MS-6905 PPGA Celeron Converter board.

[Correction]

Since I just could not make my A-MAX's card to work, I've contacted him for the confirmation. It turned out that he, himself has not yet succeeded, however he assumed, with the info. from his friend that it can be possible with MSI's MS-6905.

The Challenge with MSI MS-6905

Then I went out to Akihabara to get MS-6905 PPGA Celeron Converter Boaard.

MSI MS-6905

According to Mr. Kukperman, PPGA Celeron's BR1# pin corresponds to AN15 pin. He was saying that it may/should work if we are to connect B75 to AN15, and pull it up with Vtt voltage.

PPGA BR1# BR1#pinout

MS-6905's B75 has obvious connetion to somewhere. If this line goes to AN15, no modification is required for the dual operation of PPGA Celerons. I've tried it, but did not work. Voltmeter also indicate that it was not connected to AN15.

Then where is B75's line going? It turned out that B75 is conntected to RN17 register directly...means pull-uped by the Vtt voltage.

That means, the only modification required is to connect AN15 to B75 for the dual operation.

Connection

If you follow the pattern of MS-6905 from B75 pin, there is a hole through the board (through hole??). Make the connection from AN15 to this hole/pattern with the jumper line. It does not matter how thick the line is. I've used the same line as before, but it is preferable to use the line with the plastic insulation.

Connected AN15 and B75

Dual with PPGA & SEPP Celerons

This is it for the modification, then the operation. Fitting PPGA Celeron 300A into modified MS-6905, placing it into CPU slot on the motherboard. Remaining slot is fitted with the modified SEPP Celeron.

PPGA&SEPP 300A 2Processor(s)

SUCCESSFUL! Showing 2 processers. On the Windows NT 4.0 also recognizes PPGA Celeron 300A, stepping ID:665 as the CPU1.

SEPP(ID:660)&PPGA(ID:665)

Both CPUs are stable @463MHz with normal core voltage of 2.0V.

Some thought with conversion cards...

MSI's MS-6905 lead me to the successful dual operation, however applying same modification to the A-MAX card DID NOT. I can say that although there will be some conversion cards from various manufactures, modification that is required for MSI's MS-6905 is a snap!, for the time being. If you have succeeded in making dual operation with the other converter cards, please let me know about it!

ELITEGROUP(ECS) SmartAdapter

ECS SmartAdapter Connection

Dual is possible in the same way even with ELITEGRUOP(ECS)'s SmartAdapter. But, it may become a little unstable at the time of overclocking.

ABIT AB-RS370

ABIT AB-RS370 connection & pull-up

You must make pull-up line by the 56 ohms resistor.

A-MAX 35-7712-00-02

A-MAX Conversion board

You must make pull-up line by the 56 ohms resistor.

ASUS S-370

Refer to the following link for ASUS S-370.

ASUS S370 CPU Card modification
http://www.kikumaru.com/pc/s370tos1/asus370.html (Japanese version)

Make pull-up line by the 56 ohm resistor

The following method can be used about the adapter which pull-up should be necessary with the 56ohm resistor.

AN15 is connected with AD36 (Vtt) by the 56 ohm resistor.

Adapters

Special thanks!

*This modification information was made possible with the information from Mr. Christopher Kuperman.

I would like to thank Mr. Christopher Kuperman for supplying me the vital information regarding the BR#1 for Dual operation with PPGA Celerons. Without the info. from him, the realization of the Dual PPGA Celeron would not be this quick. Thanks again.

Dual Celeron's board
Please, discuss about Dual Celeron in the message board.

Tomohiro Kawada
E-Mail : webmaster@kikumaru.com
English translation : Shingo Kurokawa