| From: | Don Cox |
| Date: | 30 Sep 2000 at 11:03:52 |
| Subject: | Re: To sum it up |
On 29-Sep-00, G.A.Griggs wrote:
>> AC Tell me one CPU that /does/ have BCD opcodes. (ok ok, there's
>> probably AC one isn't there? :)
> Zilog Z80 as found the the ole Spectrum ,Yeah I know it only an 8bit
> Cpu but for it's time it was IMHO quite an advaced design Built in
> FPU,Blitter. By comparison the 68k chips look like RISC chips.
8 bit data port but 16 bit registers and addressing. There is an opcode for
doing BCD but there is no floating point hardware.
I suppose you could call the LDIR etc instructions a blitter, but the
blitter in the Amiga does logical operations as it copies and is much
more sophisticated.
I would say the big advantage of the Z80 over the 68000 is the separate
address range for hardware ports as opposed to RAM. But the 68000 is a
much cleaner design, and I see it is still being used for teaching
courses on microprocessor principles. (Well, you could hardly use a
Pentium.)
Regards
Quote carefully and read all ADMIN:README mails