On Fri, 11 Feb 2005, Eric Smith wrote: > > rtstofer wrote: > > And I really wish I hadn't discarded the Z80 emulation app note. > > They had great information on very wide control words. I have > > forgotten what the assembler was but I remember having to create the > > code using an 8080 macro assembler for a class I took. Great fun! > > What Z80 emulation app note was that? > > I'm familiar with two bitslice designs to emulate the 8080, one by > AMD using the 2900 series, and one by Signetics using the 3001/3002 > (which they second-sourced from Intel): I remember getting one of the 3002 8080 kits at some trade show a million years ago Our programmer still has it... > > http://www.bitsavers.org/pdf/amd/AMPUB-064_8080sim.pdf > http://www.bitsavers.org/pdf/signetics/Signetics8080emulMan.pdf > > One of the Signetics boards sold on eBay a few years ago, but I > didn't see it until too late. > > Eric > > To post a message, send it to: > To unsubscribe, send a blank message to: > Yahoo! Groups Links > > Peter Wallace Mesa Electronics

--- In , "Eric Smith" <eric@b...> wrote: > rtstofer wrote: > > And I really wish I hadn't discarded the Z80 emulation app note. > > They had great information on very wide control words. I have > > forgotten what the assembler was but I remember having to create the > > code using an 8080 macro assembler for a class I took. Great fun! > > What Z80 emulation app note was that? It was an AMD publication in a small paperback booklet. At one time I had 3 or 4 of these booklets on different topics but it was so long ago I just can't remember the details. I got far too ruthless with my library when I moved a year or so back. > > I'm familiar with two bitslice designs to emulate the 8080, one by > AMD using the 2900 series, and one by Signetics using the 3001/3002 > (which they second-sourced from Intel): > > http://www.bitsavers.org/pdf/amd/AMPUB-064_8080sim.pdf > http://www.bitsavers.org/pdf/signetics/Signetics8080emulMan.pdf > > One of the Signetics boards sold on eBay a few years ago, but I > didn't see it until too late. It is a good thing that bitsavers is out there. They have some interesting archives. > > Eric

rtstofer wrote: > And I really wish I hadn't discarded the Z80 emulation app note. > They had great information on very wide control words. I have > forgotten what the assembler was but I remember having to create the > code using an 8080 macro assembler for a class I took. Great fun! What Z80 emulation app note was that? I'm familiar with two bitslice designs to emulate the 8080, one by AMD using the 2900 series, and one by Signetics using the 3001/3002 (which they second-sourced from Intel): http://www.bitsavers.org/pdf/amd/AMPUB-064_8080sim.pdf http://www.bitsavers.org/pdf/signetics/Signetics8080emulMan.pdf One of the Signetics boards sold on eBay a few years ago, but I didn't see it until too late. Eric

Re: A bit of history
Re: A bit of history

--- In , "Eric Smith" <eric@b...> wrote: > rstofer wrote: > > I had misplaced my 8080 Microcomputer > > Systems User's Manual (Sept 1975). I have since located it - right > > on top of my "Bit-Slice Microprocessor Design" book. > > By Mick & Brick? That's an excellent book. Even though people > generally don't design using 2900-series bit slice components any > more, I still recommend it to CPU designers as there is still a lot > of good information of general applicability. > > Eric And I really wish I hadn't discarded the Z80 emulation app note. They had great information on very wide control words. I have forgotten what the assembler was but I remember having to create the code using an 8080 macro assembler for a class I took. Great fun!

rstofer wrote: > I had misplaced my 8080 Microcomputer > Systems User's Manual (Sept 1975). I have since located it - right > on top of my "Bit-Slice Microprocessor Design" book. By Mick & Brick? That's an excellent book. Even though people generally don't design using 2900-series bit slice components any more, I still recommend it to CPU designers as there is still a lot of good information of general applicability. Eric

Re: A bit of history

John According to the time stamp on my post, it was about 11:21 PM - seems right. Yours was about 11:30 PM - all my time (US PST). Seems I recall calculating for some place in Australia that you were 18 hours ahead. Or, California is 6 hours ahead in time but on the previous day. And then we have to factor in Daylight Savings Time. I remember when I went to work in Singapore the days it took to recover from the 16 hour time shift. It was a lot easier recovering from the 8 hour shift when I returned. Richard --- In , John Kent <jekent@o...> wrote: > Hi Richard, > > The 6800 I understand because of one (E) Clock = 1 cycle = 1usec. > > Anyway ... what are you doing up this time of night ? > 6pm in Australia ... not sure what that is in the US, > but I bet it's early in the morning :-) > > John. > > rtstofer wrote: > > > > >The AGC has a truly bizarre architecture - clearly application > >specific. Because the machine was so limited in memory they > >actually wrote and interpreter and most application programs were > >interpreted strictly to save memory. They could use lots of lights - > > the machine was slow enough to see them flash! > > > >The AGC used a 1.024 MHz clock and the fast instructions used 12 > >clock cycles. Memory cycles were 11.7 uS. The 8080 started out at > >2 MHz, fast instructions used 2 clock cycles, memory access was 1 uS > >(IIRC) and the address space was much larger. > > > > > > > > -- > http://members.optushome.com.au/jekent

You are correct, of course. I had misplaced my 8080 Microcomputer Systems User's Manual (Sept 1975). I have since located it - right on top of my "Bit-Slice Microprocessor Design" book. I just have to get organized someday... --- In , "Eric Smith" <eric@b...> wrote: > > The 8080 started out at 2 MHz, > > So far so good. Later the 8080A-2 was rated at 2.5 MHz,and the 8080A-1 > at 3 MHz. > > > fast instructions used 2 clock cycles, > > No. Instructions take between one and five "M cycles", each of which > can perform one memory cycle and/or some internal operations. Each > M cycle takes between one and five "T states" (clock cycles). The > fastest instructions take four clocks, and the slowest (XTHL) takes 18 > clocks. > > > memory access was 1 uS > > The memory access time is misleading. Memory cycle time is more useful. > For a 2 MHz 8080, an instruction fetch cycle takes 4 cycles (2 us), and > other memory cycles take at least 3 cycles (1.5 us). > > Reference: Intel 8080 Microcomputer Systems User's Manual, September 1975, > Intel literature part number 98-153C.

> The 8080 started out at 2 MHz, So far so good. Later the 8080A-2 was rated at 2.5 MHz,and the 8080A-1 at 3 MHz. > fast instructions used 2 clock cycles, No. Instructions take between one and five "M cycles", each of which can perform one memory cycle and/or some internal operations. Each M cycle takes between one and five "T states" (clock cycles). The fastest instructions take four clocks, and the slowest (XTHL) takes 18 clocks. > memory access was 1 uS The memory access time is misleading. Memory cycle time is more useful. For a 2 MHz 8080, an instruction fetch cycle takes 4 cycles (2 us), and other memory cycles take at least 3 cycles (1.5 us). Reference: Intel 8080 Microcomputer Systems User's Manual, September 1975, Intel literature part number 98-153C.

Hi Richard, The 6800 I understand because of one (E) Clock = 1 cycle = 1usec. Anyway ... what are you doing up this time of night ? 6pm in Australia ... not sure what that is in the US, but I bet it's early in the morning :-) John. rtstofer wrote: > >The AGC has a truly bizarre architecture - clearly application >specific. Because the machine was so limited in memory they >actually wrote and interpreter and most application programs were >interpreted strictly to save memory. They could use lots of lights - > the machine was slow enough to see them flash! > >The AGC used a 1.024 MHz clock and the fast instructions used 12 >clock cycles. Memory cycles were 11.7 uS. The 8080 started out at >2 MHz, fast instructions used 2 clock cycles, memory access was 1 uS >(IIRC) and the address space was much larger. > -- http://members.optushome.com.au/jekent