Re: [N8VEM-S100:3558] Re: Group order for S100 V2 80286 Master/Slave CPU Board

Hi Paul,

Yes, I read webpage on the 80286 card some time ago.

I was just wondering if the 15Mhz 'top out' is more due to reaching the upper limit of the 82C284-12 and 82288-10 parts that are shown in the pictures of his card,

John does mention something to the effect of 'your milage may vary', Maybe the Siemens parts (as per the datasheet) may be able to get the board to 16Mhz with a few wait states to slow the bus access, for me part of the fun is seeing what can be achieved.

The other point I was trying to offer is that the SAB82288-I-P chips are available on ebay for a fraction of the price of the Intel parts, this may be the solution you need regarding your original post.

http://www.ebay.co.uk/itm/SAB82288-I-P-SIEMENS-20-Pin-NEW-SAB82288-1-P-P82288-/120545267057?pt=LH_DefaultDomain_0&hash=item1c110ecd71#ht_198wt_927

best regards

David Fry

On Friday, May 9, 2014 12:25:16 PM UTC+1, pbirkel wrote:

Well, note that John states that he wasn't able to achieve stable performance @15MHz ("The board with an AMD 80C286-16 CPU I could get the board to run in my system with a 15MHz Oscillator "most of the time". However I normally run the board with a 12 MHz AMD N80L286-12 (no I/O wait states), with on-board 28C256 EEPROMS or off-board EEPROMS on the MS-DOS support board. At this speed the board is absolutely rock solid.") and the S-100 bus does "top out" around 12 MHz. Adding wait states might get you to 16+ on the CPU. John doesn't mention whether he tried trading wait-states for CPU speed. Experiment!

On Fri, May 9, 2014 at 6:43 AM, David Fry <dgf...@googlemail.com> wrote:

John / Paul,,

have a look at the attached datasheets, looks like Siemens did faster versions of the 80288 and 80284 support IC's.

Would they work on our 80286 boards at maybe 16Mhz~ 20Mhz with a 20Mhz CPU?

regards

David Fry

On Saturday, April 26, 2014 6:58:19 PM UTC+1, monahanz wrote:

Hi everyone,

I'm going to quickly do a “Production” run of the V2-80286 Master/Slave CPU board. This is a rework and upgrade of the original 80286 board. The differences/improvements are listed towards the bottom of this page.

http://s100computers.com/My%20System%20Pages/80286%20Board/80286%20CPU%20Board.htm#V2-80286

This is a fairly complex board and probably not for some to start with in the 16 bit S100 arena. However it may be some time until we do another run.

I will be traveling (again) soon, so I would like to get the order out early next week. Please let me know if you would like one or more boards (via e-mail to monahan AT vitasoft.org).

Also please it is lightly we will be below the normal number of boards (20) to get the low $33 price, could be 2X that. If that is a problem let me know.

John

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