MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
1993 article on building a multiprocessor 6809 box. http://www.bradrodriguez.com/papers/6809cpu.htm -- Liam Proven - Profile: https://about.me/liamproven Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
On 8/2/2019 11:15 AM, Liam Proven via cctalk wrote: 1993 article on building a multiprocessor 6809 box. http://www.bradrodriguez.com/papers/6809cpu.htm Read that page years ago.I have always like the 6800 CPU model.I have used that model for a 18 and 20 bit cpu design currently being bread boarded in DE1 FPGA development kit, ~900 logic blocks and a few small ROM blocks. Where are all the articles about a TTL designed computer? Yes I know about (Homebuilt CPUs ring) but that is mostly today. What about the Late 70's and Early 80's? I need a the web site "C compiler for the IMPOVERISHED", I have Ron Cain's 1.0 Small C compiler modified to generate code for my architecture but the code is really inefficient. It is the only C compiler with source that fits in 64KB. (8080) Ben.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
> On August 2, 2019 at 5:49 PM ben via cctalk wrote: > > > On 8/2/2019 11:15 AM, Liam Proven via cctalk wrote: > > 1993 article on building a multiprocessor 6809 box. > > > > http://www.bradrodriguez.com/papers/6809cpu.htm > > Read that page years ago.I have always like the 6800 CPU > model.I have used that model for a 18 and 20 bit cpu design > currently being bread boarded in DE1 FPGA development kit, > ~900 logic blocks and a few small ROM blocks. > > Where are all the articles about a TTL designed computer? > Yes I know about (Homebuilt CPUs ring) but that is mostly > today. What about the Late 70's and Early 80's? > > Ben. Byte had a 2 article series in September and October 1985 of EGO, a 16 bit TTL cpu: https://www.americanradiohistory.com/Archive-Byte/80s/Byte-1985-09-10th-Anniversary.pdf https://www.americanradiohistory.com/Archive-Byte/80s/Byte-1985-10.pdf Will "A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away." -- Antoine de Saint-Exupery "The names of global variables should start with // " -- https://isocpp.org
RE: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
> -Original Message- > From: cctalk On Behalf Of ben via cctalk > Sent: 02 August 2019 23:50 > To: cctalk@classiccmp.org > Subject: Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 > Uniprocessor > > On 8/2/2019 11:15 AM, Liam Proven via cctalk wrote: > > 1993 article on building a multiprocessor 6809 box. > > > > http://www.bradrodriguez.com/papers/6809cpu.htm > > Read that page years ago.I have always like the 6800 CPU model.I have used > that model for a 18 and 20 bit cpu design currently being bread boarded in > DE1 FPGA development kit, > ~900 logic blocks and a few small ROM blocks. > > Where are all the articles about a TTL designed computer? > Yes I know about (Homebuilt CPUs ring) but that is mostly today. What about > the Late 70's and Early 80's? > Many were not published. A friend built a TTL computer based on the PDP-8 but no details were published. There was a design in the UK called the "weeny-bitter" in the Amateur Computer Club newsletters. Not sure how many got built... Information is scattered through the magazines. I think start at volume 2... http://www.smrcc.org.uk/members/g4ugm/acc.htm Dave > > I need a the web site "C compiler for the IMPOVERISHED", I have Ron Cain's > 1.0 Small C compiler modified to generate code for my architecture but the > code is really inefficient. > It is the only C compiler with source that fits in 64KB. (8080) Ben. > > >
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
Many were not published. A friend built a TTL computer based on the PDP-8 but no details were published. There was a design in the UK called the "weeny-bitter" in the Amateur Computer Club newsletters. Not sure how many got built... Information is scattered through the magazines. I think start at volume 2... http://www.smrcc.org.uk/members/g4ugm/acc.htm Dave Thank you. That is better reading than BYTE. 250 pages of full page ADS before you hit the text content. My only question is how much a Pound was in Canadian Dollars in 1976? Ben.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
On 08/03/2019 02:06 PM, ben via cctalk wrote: Many were not published. A friend built a TTL computer based on the PDP-8 but no details were published. A field service tech at a company I once worked for built a 16-bit computer that was a whole generation better than the 12-bit machines that company made. I know a few of them were built by others that worked there. Most programs were entered through the front panel switches. This was probably about 1976 or so. Display was via an oscilloscope. It was called the Mike Smith 1. I've never found any reference to it online. Jon
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
Ben said > Where are all the articles about a TTL designed computer? > Yes I know about (Homebuilt CPUs ring) but that is mostly > today. What about the Late 70's and Early 80's? Well there's the EDUC-8, based on the PDP-8 instruction set and was published from 1974 to 1975 by Electronics Australia magazine, followed by a number of articles on building peripherals. https://en.wikipedia.org/wiki/EDUC-8 I have all the original magazine issues for it, but you can get them all in book form from Silicon Chip magazine these days https://www.siliconchip.com.au/Shop/3 Steve.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
On 8/5/2019 1:40 AM, Steve Malikoff via cctalk wrote: Ben said Where are all the articles about a TTL designed computer? Yes I know about (Homebuilt CPUs ring) but that is mostly today. What about the Late 70's and Early 80's? Well there's the EDUC-8, based on the PDP-8 instruction set and was published from 1974 to 1975 by Electronics Australia magazine, followed by a number of articles on building peripherals. https://en.wikipedia.org/wiki/EDUC-8 I saw that a few times but I never could find the link again. I have all the original magazine issues for it, but you can get them all in book form from Silicon Chip magazine these days https://www.siliconchip.com.au/Shop/3 I suspect you can't get the PCB's any more and the card edge connectors. Steve. The Amateur Computer Club magazines gave me just what I was looking for as they had prices listed for the chips sold at the time. I noticed several people were finding very old machines for a song, (1972-1977) did that happen also here in America? Ben.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
On Fri, Aug 2, 2019 at 11:15 AM Liam Proven via cctalk < cctalk@classiccmp.org> wrote: > 1993 article on building a multiprocessor 6809 box. > http://www.bradrodriguez.com/papers/6809cpu.htm > I disagree very much with the author's advice to use the MC6809 rather than the MC6809E. With the E version you have to supply a quadrature clock, but all that's required to generate that is a single-phase 4x clock (which you need with either the E or non-E part) and a single 74HCT74. If you feed your single-phase 4x clock into multiple 6809 (non-E) parts, their E clock phases won't match, but will be off by arbitrary multiples of 1/4 cycle, which makes the shared memory design unnecessarily difficult.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
On Tue, Aug 6, 2019 at 1:19 AM Eric Smith wrote: > With the [MC6809]E version you have to supply a quadrature clock, but all > that's required to generate that is a single-phase 4x clock (which you need > with either the E or non-E part) and a single 74HCT74. > In case anyone needs to see how this is done, I've attached a schematic. It is shown with an 8 MHz half-can oscillator, which will result in 2 MHz outputs suitable for an MC68B09E, which is rated for 2 MHz operation.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
I built a dual-6809 in the late '70s - it was a brand-new, exciting part - and we used the E part for exactly that reason. The system used memory that had an access time that was better than the 4x clock, so that each processor could run at full speed. From: "cctalk" To: "Liam Proven" , "cctalk" Sent: Tuesday, August 6, 2019 12:19:55 AM Subject: Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor On Fri, Aug 2, 2019 at 11:15 AM Liam Proven via cctalk < cctalk@classiccmp.org> wrote: > 1993 article on building a multiprocessor 6809 box. > http://www.bradrodriguez.com/papers/6809cpu.htm > I disagree very much with the author's advice to use the MC6809 rather than the MC6809E. With the E version you have to supply a quadrature clock, but all that's required to generate that is a single-phase 4x clock (which you need with either the E or non-E part) and a single 74HCT74. If you feed your single-phase 4x clock into multiple 6809 (non-E) parts, their E clock phases won't match, but will be off by arbitrary multiples of 1/4 cycle, which makes the shared memory design unnecessarily difficult.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
On 8/6/2019 6:38 AM, Norman Jaffe via cctalk wrote: I built a dual-6809 in the late '70s - it was a brand-new, exciting part - and we used the E part for exactly that reason. The system used memory that had an access time that was better than the 4x clock, so that each processor could run at full speed. It was too bad the 6809 did not have a pin to indicate Instruction or Data memory bank in use. That would of given a real unix system in the 8 bit world, as by then (late 70s) 64kb was proving just to small for any real use. The 68000 was the only real 16/32 bit cpu out at time, but nobody could afford it. Ben.
Re: MULTIPROCESSING FOR THE IMPOVERISHED Part 1: a 6809 Uniprocessor
Ben wrote on Tue, 6 Aug 2019 13:47:59 -0600 > It was too bad the 6809 did not have a pin to indicate Instruction or > Data memory bank in use. That would of given a real unix system in the > 8 bit world, as by then (late 70s) 64kb was proving just to small for > any real use. I added a circuit to generate such a signal in my 1983 children's computer: http://www.smalltalk.org.br/fotos/pegasus1.jpg If I remember correctly, it only used half of a 74LS74. The notebook with the circuit is a bit hard for me to get to right now. It didn't work perfectly since it depended on there being a non memory cycle between fetching the instruction bytes and the data access. And that doesn't happen if you use the zero offset addressing mode. So I just wrote my assembler to never generate that. Instead it used a five bit offset with a value of zero. This wastes a byte and a clock cycle but I thought it was worth it. The extra signal was used to select between ROM and DRAM. This meant I couldn't fetch data from ROM nor execute code from DRAM but since the only program I was interested in was the Logo interpreter it seemed like a reasonable design. I did have a Logo compiler planned, which would not have worked with this. > The 68000 was the only real 16/32 bit cpu out at time, but nobody could > afford it. The 6809, and specially the 6809E were hardly cheap themselves. And their prices stayed stable while the 68000's dropped quite a lot. By late 1985 the difference was rather small. And the 6847/6883 chipset was expensive too, at around $40 for these two chips. I regretted using them as you can get a lot of TTLs for $40 and have far nicer video than they gave you, specially if you didn't care about the built in text modes. -- Jecel
