Gigatron Hackers

Just run all the different sieve versions.
Sieve0: 41.1 seconds normal screen mode
Sieve0: 28.67 seconds fast screen mode <- Ratio 2.05

Sieve1: 39.22 seconds normal screen mode
Sieve1: 27.57 seconds fast screen mode <- Ratio 1.97

Sieve2: 29.72 seconds normal screen mode
Sieve2: 20.87 seconds fast screen mode <- Ratio 1.49

To me it seems very fast for whats inside the machine. Good job engineering this device!

Did you use the same compilation option -map=64k,hionly as https://github.com/lb3361/gigatron-lcc/ ... e/Makefile ? That shouldn't impact the ratios but make the code a bit faster by avoiding long jumps between screen holes..

lb3361 wrote: ↑01 May 2022, 14:37 Also, did you use the same compilation option -map=64k,hionly as https://github.com/lb3361/gigatron-lcc/ ... e/Makefile ? That shouldn't impact the ratios but make the code a bit faster by avoiding long jumps between screen holes..

I only changed -rom=dev, otherwise it was compiled same way

That's probably correct. Modern computers are really fast, especially when they can work entirely from the memory cache...

This is little bit OT, but did everybody knew that Cray 1 supercomputer 1970's used only ICs and had 200 000 gates. 1990's they started to use microprocessors. Thanks to sieve now we can compare all the machines. Cray 1 supercomputer(Fortran)-Sieve-benchmark 0.110 seconds. Thats 190 times faster than GigatronTTL.

Nice. 190 times faster and 200.000 times more expensive

Still, the Cray-1 is better looking than the Gigatron. There's in in the Heinz Nixdorf museum in Paderborn Germany.

What would have been the price of Gigatron in the 70s? ICs were not as cheap, especially SRAM. Still a good deal compared to a Cray1...

To get real world load to todays computers I modified sieve to "toughsieve"

lb3361 wrote: ↑02 May 2022, 11:14 What would have been the price of Gigatron in the 70s? ICs were not as cheap, especially SRAM. Still a good deal compared to a Cray1...

I have found various magazine adverts in online archives for TTL ICs from the 1970s.

Almost all of the TTL ICs used in the Gigatron were available by 1975. Typically they cost between $1 and $2 back then, but $1 in 1975 is the equivalent of $5.34 in 2022 prices.

EPROM and RAM were still very expensive, and had slow access times. EPROM was about 450nS and RAM about 250nS. That would slow the Gigatron clock down to about 1MHz.

You would probably only afford about 2K words of ROM and 2K of RAM. A video screen would have been out of the question, unless you used a character ROM or a serial terminal interface.

Custom made PCBs were unheard of back then - so you would probably have used wirewrap sockets on a big prototyping board.

Probably the best comparison is the Apple I from 1976 which was $666.66 in kit form, about $3000 equivalent today.

We are very lucky that we can buy a Gigatron kit today for about $100!

Messing around with Mode 1975 and new instructions recently added to ROMvX0, we have a new leader board champ!