On 2018-03-08 6:49 PM, allison via cctalk wrote:
On 03/08/2018 05:38 PM, Paul Berger via cctalk wrote:
Hmmmm I don't remember my original PC having all the chips in sockets
nor do I recall it having 64Kb DRAMs. I clearly recall that it had
one bank of 16Kb DRAMs soldered down and sockets for three more banks
of 16Kb chips. The only other sockets on the board where for the ROM,
CPU, and math coprocessor. hardly a fathful reproduction.
Paul.
Paul,
That is the rev-b still 5150 but the next 4 digits are that hardware it was.
your correct the first version only took 16k Drams x4 banks (64K). It was
very obvious that was way too little and a "few" revs were done to use 64K
and later 256K parts.
Personally why would any one want to build that? It ran at 50% of what
the 8088 could do in the day and was memory poor. I know that as I was
running a Multibus 8088 at 8mhz just as that was introduced. That
was faster.
Allison
Ok I was not aware there was a second version I got mine in Nov. 81, and
I agree who would really want one. If you really wanted the 4.7MHz
experience, I still see lots of PC and XTs go by on eBay. I never did
bother keeping a planar from an original PC, but have 2 from XTs. One
thing the original PC was useful for was the cassette interface on it
could be used to emulate a TTY device for deaf people. A long time ago
I built a clone of it on a ISA bus card for a person that wanted to use
it in an XT.
Paul.
