28 Mar
1998
28 Mar
'98
12:22 a.m.
<Obviously this is meant to over clock the 286, with the rotary switch
<allowing increasing the clock frequency until the 286 fails.
Overclocking another retrorevionistpc idea.
No most likely it allowed you to buy the fastest 286 and clock it at it's
native speed.
<1) Does this really work? I thought you couldn't over clock a true AT?
< (This particular motherboard is a "256/512 K System Board" with
< piggy-backed RAM chips. It has lots of "ECOs" on the pin side of
< the board. I don't know if my other one does, too. Note: ECO =
< Engineering Change Order.)
Nah. It was done all the time on the original AT's which went from 6mhz to
8 in seconds.
However, IBM hacked up the new (8mhz model roms) to stop this from happening.
So, while IBM had 8mhz AT's until Microchannel the clones ran up to 20Mhz
286's. (Which beat early 386 16's at raw dos speed).
The AT might go a little faster, at some point the DRAM timing goes flakey
and otehr things start to get cranky.
That's especially true of the ISA cards!
<2) Would increasing the 286-6 to a 286-8,10,12 increase the frequency
< at which it could reliably run? I have a PGA 286-8, but I'm not
< sure there are faster PGA 286s?
There are it went all the way to 12 or 16mhz. I have a LCC version thats
12 and the PS/2m50s I have are 10mhz.
<3) Any software needed? (The ROMs appear to be the same as on my other
< machine.)
None but the rams may get unhappy of pushed to fast (data takes time to
get out).
Allison
Bill
+---------------------------------------------------------------------------+
| Bill/Carolyn Pechter | 17 Meredith Drive | Tinton Falls, New Jersey 07724 |
| 908-389-3592 | Save computing history, give an old geek old hardware. |
| pechter(a)shell.monmouth.com |
+---------------------------------------------------------------------------+