14 May
2014
14 May
'14
12:29 p.m.
i had one 512 to 1mb upgrade. it was a dove computing card with soldered
on chips. is socketed in a few places in stead of the original chips, or
just between the cpu and the mobo. i forget. the box with the boards ia
somewhere in our computer museum. i will dig it op soon because we are
finally organising the depot.
simon
On 14-05-14 03:08, David Riley wrote:
On May 13, 2014, at 20:02, "drlegendre ."
<drlegendre at gmail.com> wrote:
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
So.. does your 1MB "128K" have a set of SIMM slots with SIMMs plugged-in?
That would be a Plus board, if memory serves.
It's definitely not a Plus logic board; no SCSI, for one thing.
I have an uncle who worked for Apple around the time, and
I think he was the major source of upgrades. In any case,
I'll be able to speculate further once I get a chance to open
the box; I have the tools, but the machine itself is still
at my parents' house in a different state. One of these days
I'll bring it back here, but I did at least make sure to remove
the battery last time I looked at it.
IIRC, the 128K and 512K models had everything
soldered (no SIMMs, no
sockets) directly to the motherboard. And as such, an upgrade would require
some very dicey solder re-work to replace the chips, or some sort of
piggyback arrangement, which I've seen on other 80s era machines - and
video game consoles.
Indeed, but it was the same board, with the changeable
areas silkscreened appropriately. Yes, you need to swap
out the 4164s for 41256s, add in an 'AS257 (if memory
serves) and jumper some wires, but it was doable. 1MB
required some reengineering, though. I'm curious to see
what was done, since I doubt my uncle would have added
a third-party expander (too much pride in workmanship).
- Dave