2 ms·
Not to go all Yorkshire, but I used to dream of having a KIM-1. My first computer — the best thing I could afford — was a Quest Super Elf [ http://www.oldcomput
by kps 14y ago
Not to go all Yorkshire, but I used to dream of having a KIM-1. My first computer — the best thing I could afford — was a Quest Super Elf [ http://www.oldcomputermuseum.com/super_elf.html http://www.oldcomputermuseum.com/super_elf.html ] with 256 bytes of RAM, and a processor on which a recursive subroutine call took 16 instructions.
On the other hand, by 1985 I was doing QA for a 64-bit Unix environment.
- jekub 14y agoYou're joking, this was a wonderful machine. Especially the CDP1802 processor with its ability to use any register as a PC. I've very nice memory with this chip.
- kps 14y agoIn some ways it was nice. For those unfamiliar: The 1802 had sixteen general purpose 16-bit registers. Any one of these could be selected as the program counter. In a tiny embedded system (which is what the part was meant for), you might choose to designate one as the ‘normal’ PC and reserve a few others for important subroutines, which could then be invoked with a one-byte ‘SEP n’ instruction. Similarly you could implement coroutines or simple task switching by switching the selected PC between a pair of registers. On the other hand, there was no conventional call instruction. The SCRT (“Standard Call and Return Technique”) for recursive or reentrant subroutines essentially involved defining (non-reentrant) coroutines to perform the ‘recursive call’ and ‘recursive return’ operations.