On 2024-02-27 3:09 p.m., Paul Koning via cctalk wrote:
On Feb 27, 2024, at 4:49 PM, CAREY SCHUG via
cctalk <cctalk(a)classiccmp.org> wrote:
Religion warning: I was a mainframer. Since at any practical budget, they can only be
emulated,
Dumpster diving is a 0 dollar budget.
People could afford the APPLE II, 8080 S-100 bus, SWTPC 6909. I assume
with careful shopping one can rebuild them for about the same price, in
small quanities.
Power supplies require harder to find parts.
Main frame rebuilding is costly, but I suspect the real cost is I/O
that can't be duplicated. A hardware emulation using microcode to me
is real computer, a windows fly by night emulation is not, as the base
platform is too unstable.
Depends on your definition of emulated. Is an FPGA
version merely an "emulation"? You might say yes if it's a functional
model. Arguably no, if it's a gate level model.
I have bad luck with FPGA's, too many timing issues with routing.
I have better luck with a 2901 4 bit alu and some support logic mounted
on a small pcb.
Suppose you had schematics of, say, a KA-10. You
could turn those gates into VHDL or Verilog, and that should deliver an exact replica of
the original machine, bug for bug compatible. That assumes the timing quirks are
manageable, which for most machines should be true. (It isn't for a CDC 6600.)
paul
The IBM 1130 is also a pretty scary machine inside.
The blog is here.
https://rescue1130.blogspot.com/
Ben.