On 17/08/13 3:02 PM, Tony Duell wrote:
Transputer was actually a very simple and elegant design -- and very
Yes. I used a couple for my Ph.D. work and I've yet to see a processor
that is easier to interface or program.
I still want to build a homebrew SBC based on one or two.
It is veyry easy.. The T4 and T8 (at least) have a configurable memoery
controller on-chip. For most applciations you just tie one of the pins on
the Trnasputer ot one of the address/data lines to set it up.
You have an on-chip refresh counter and you can set up the timing stobes
to be essntially RAS/, addres smultplex, and CAS/ so linking up standed
DRAM (4164s, 41256s) is easy. SRAM is easier still, of course.
There is some on-chip RAM, but you nearly always need to add some
Yo ucan boot eitehr from one of the links (this is the normal method) or
fro ma ROM in the transmputer's address space (I forget the start
address, it's in the data sheet). Again selected by a pin on the transputer.
The only mild problem is that you _must_ fit that 1uF capacitor to
decouple the suppl to the clock PLL, and it must be a low-inductance
Oh yes, addresses are 2's compliment, signed (!). This practical
implication of this is that it makes a lot of sense to invert the MSB of
the address bus, which then givs you what uou might expect...
I feel that they were intially mis-marketed. They were pushed as a
processr for doing parallel processing (which in a sense is true) with
the result that peopel ignored them becuase they didn't need to do
parallel processing. In fact ther wrre a very nice _microcontroller_.
They were almost ideal for high-performance embedded systems -- like
fast data acquistion devices (what I used them for) and the like.
Yes. The product line was even helpfully segmented along these lines,
between the T2xx, T4xx, and T8xx, along with a good palette of glue
Teh T2 is the oddity in hardwar. It has a 16 bit data bus and IIRC 14
address lines on separate pins. The T4s and T8s have a 32 bit multiplexed
addres/data bus. IIRC The T414, T425 and at least one of the T8s were pin
compatible. If you built a bvoard with a T4 on it and decided you wanted
a flation point devive, you could pul lthe T4, plug in a T8 and expect it
There wa astrange version of the T8 (T801? T805?) which was optimised for
fast (at the time) static RAM. I've never designed with it, just seen it
on a TRAM.
chips from Inmos for I/O, etc.
The registrrs on those link adapters reminded me -- a lot -- of a DEC DL11