Zilog To File For Chapter 11
Frédéric writes: "The venerable company ZiLOG who was founded in 1974, and who brought us the famous Z80 CPU (used in the Timex/Sinclair ZX80/ZX81, and the Amstrad CPC/PCW computers), is filling for Chapter 11 ... I didn't find the today's news on the web, but found this article at Silicon Strategy and this one at Electronics times, which was written a few days ago to announce it."
Z80 also powered the sound chip in the Sega Genesis and a modified chip was used in the Gameboy.
Pop quiz, hot shot. Tell me what this Z80 code does...
LD BC,0FFFFH
LOOP: DEC BC
JP NZ,LOOP
Zilog not only made processors but also a rich array of peripheral chips including SCSI chips used in earlier Sun and Macintosh workstations. Unfortunately, Zilog got too big for its britches and forgot who brung them to the dance: small independent software developers. In recent years, unless they thought you were going to place an order for one million chips, their attitude became "go away, son, you bother me."
Can't say that I'll cry any tears for Zilog.
Man, lots of fond reminiscing here about the Z80 (and clones). Quite rightly, too... the Z80 was a fun little beast.
... rr14). The Z8001 and Z8003 were "segmented", but they used a reasonable segmentation model to achieve 8M memory...
Zilog, however, made lots of other stuff. Some were moderately successful (Z8530 SCC), some not so (Z8000 MPU).
The Z8000 actually was fairly popular in military applications until COTS took over. I seem to recall many avionics systems used it. When it came out, it was comparable to the 68K.
It had 16 16bit registers (r0-r15), each of which could be addressed as 2 8-bit registers (rhN, rlN). R15 was the stack pointer. Nice orthagonal instruction set, with logical block moves (similar to the Z80 LDIR instruction), as compared to the intel REP instructions...
The registers could be doubled up into 32-bit registers (rr0, rr2,
The low 16 bits were the offset in the segment, and the high 7 bits were the segment number. So, you essentially had 23 bit addressing. Of course, the way you generated segmented addresses was a tad odd... I believe bits 30:24 were the segement number in a 32-bit address.
Only problem was, they never got the Z8070 FPU working. Bummer.
Fascism starts when the efficiency of the government becomes more important than the rights of the people.