[cctalk] Re: Apple 1

On Thu, Aug 17, 2023, 21:27 Chuck Guzis via cctalk <cctalk(a)classiccmp.org> wrote: The IMP-16 and PACE architectures were similar (and similar to the DG Nova), but they weren't binary or source compatible. Apparently NS didn't think there was enough of an existing IMP-16 software base to worry about compatibility, and instead tried to take the opportunity to make (minor) architectural improvements. A few hobbyists built IMP-16 and PACE/INS8900 computers, and there were even a few commercial products, e.g. the Pacer microcomputer from Product Support Engineering. The IMP-16 and PACE, and even the NMOS INS8900, are very slow. For most workloads, a 2 MHz 8080 can outperform them. I've run figForth on a PACE. The published listing had a small but serious error. The original listing and my fix are on Bitsavers. The author of the PACE implementation thinks that the listing sent to FIG was by mistake not his up-to-date working version. Demonstrating the lack of popularity of PACE, apparently no one ever complained about it until I discovered and fixed the bug in 2009. I'd like to modify PACE figForth to run on an IMP-16, but there's a surprisingly large amount of work required.