Replica IBM 5150 PC motherboard
phb.hfx at gmail.com
Thu Mar 8 16:59:56 CST 2018
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.
> 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.
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.
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