View unanswered posts | View active topics It is currently Wed Sep 18, 2019 8:52 pm

Search found 72 matches
Search these results:

 Search 
Author Message

 Forum: CPU/MCU choices and designs   Topic: Cambridge-1

 Post subject: Re: Cambridge-1
Posted: Sun Sep 15, 2019 3:52 pm 

Replies: 3
Views: 36

Hi Ed, Richard has been burning the midnight oil for about a month to get the Cambridge-1 together in time for last weekend's RC Festival. Using an Arduino to help with the Bring-Up is a neat idea ( and also covered well in Ben Eater's latest video on the 6502 https://www.youtube.com/watch?v=LnzuMJL...

 Forum: CPU/MCU choices and designs   Topic: Cambridge-1

 Post subject: Cambridge-1
Posted: Sun Sep 15, 2019 3:17 pm 

Replies: 3
Views: 36

Whilst at the Retrocomputer Festival in Cambridge last weekend, I shared a corner of the room with Richard J. Grafton of Arith-Matic. Richard had spent 30 days in August building a 4-bit breadboarded TTL computer he calls the Cambridge-1. It's a neat design, which currently uses an Arduino for progr...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Sat Sep 14, 2019 10:20 am 

Replies: 23
Views: 540

Joan, Wikipedia has an entry under "Bit-Slicing" which explains it well and has examples of historical cpus that have used the technique. https://en.wikipedia.org/wiki/Bit_slicing I have estimated that my design will have approximately 64 ICs in the ALU, registers and memory addressing sec...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Sat Sep 14, 2019 7:51 am 

Replies: 23
Views: 540

Hi Joan, Regarding "Digital" my understanding from the Installation notes was that it would run on any platform: There is no installation required, just unpack the Digital.zip file, which is available for download. On Windows machines the EXE file can be executed, on Linux start the shell ...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Fri Sep 13, 2019 4:50 pm 

Replies: 23
Views: 540

I have now begun my sabbatical year - having left paid work yesterday afternoon. I can now focus on my hobby projects, which include designing a 16-bit TTL cpu, learning verilog to familiarise myself with open source FPGAs and doing some more coding. A friend suggested I look at "Digital" ...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Fri Sep 06, 2019 8:16 pm 

Replies: 23
Views: 540

Ed,

Thanks for the heads-up. Camberley is not too far from me for at least a day trip.

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Fri Sep 06, 2019 1:54 pm 

Replies: 23
Views: 540

As an update to the bitslice design. The Postman arrived this morning with a highly prized package of 74F219 16x4 RAMs. I got these from LittleDiode - a supplier in South London who keep a lot of rare stuff. https://www.littlediode.com/components/home.php They are date-stamped 8818, and I am hoping ...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Wed Sep 04, 2019 8:27 am 

Replies: 23
Views: 540

Hi Ed, Thanks for your interest. Having been inspired by the Gigatron, and it's approach to getting the most from a minimum architecture, I'm ready to take on a new challenge. I've been following the thread over on the 6502.org forum, regarding a faster implementation of the 6502 in TTL - which has ...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Tue Sep 03, 2019 10:33 pm 

Replies: 23
Views: 540

Thanks for your interest Joan.

I just wish for a simple 16 bit architecture, which we can all discuss here.

Best

Ken

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Tue Sep 03, 2019 4:59 pm 

Replies: 23
Views: 540

As an update to the proposed 4-bit bitslice design. I found some 74F219 (16 x 4 bit RAMs), so I guess that's my register file sorted I also revisited Wozniak's Sweet 16, and pondered whether this might make a suitable machine ISA to implement in TTL. It simplifies the instruction set - as all regist...

 Forum: Projects   Topic: Possibly the most short lived diy processor.

Posted: Thu Aug 29, 2019 9:48 pm 

Replies: 4
Views: 402

Thanks for sharing the details of this fascinating university spring term project. Somehow I guess I just took all the wrong courses, in the wrong country, at the wrong time. Nevermind - I'm taking a sabbatical year - starting in 2 weeks, and hope to spend time filling in the gaps of my education. B...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Fri Aug 23, 2019 8:15 pm 

Replies: 23
Views: 540

B. I realise that there are still some places where you can find the '181 (and even the '172) but for a viable project, I'd really be looking for major sources with 100+ pricing. I like the idea of a bitslice, and having prototyped a 4 bit version on a breadboard, the move to a low cost pcb, is less...

 Forum: CPU/MCU choices and designs   Topic: Bitslice using currently available TTL

Posted: Fri Aug 23, 2019 5:43 pm 

Replies: 23
Views: 540

Hi All, As technology moves on, many of the devices available to TTL designers have long since been obsoleted. I recently looked at Brad Rodriguez's PISC cpu of 1994 and lamented that two of the key parts were no longer available. https://bradrodriguez.com/papers/piscedu2.htm The 74xx181 ALU and the...

 Forum: Projects   Topic: Kobold - an innovative 16 bit TTL Retrocomputer

Posted: Fri Aug 23, 2019 5:10 pm 

Replies: 1
Views: 275

Hi All, Over on hackaday.io Roelh has been busy with his latest TTL project https://hackaday.io/project/164897-kobold-retro-ttl-computer It's a 16-bit machine, entirely in 74xx TTL, with a 20 bit address space. The instruction set is inspired by PDP-11 and 68000. The cpu is 5.4" x 4" and c...

 Forum: General Discussions   Topic: Teensy 4.0 - 600MHz ARM Cortex M7 dev-board

Posted: Fri Aug 16, 2019 4:59 pm 

Replies: 1
Views: 214

Hi All, It's never been easier to get hold of a fast microcontroller in a breadboard friendly package. The Teensy 4.0 was announced about a week ago and comes in a 24 pin DIP module. It's based on the NXP 600MHz Cortex M7 and sells for $19.95. With 2MB of flash and 1MB of RAM it's a useful board for...
Sort by:  
Page 1 of 5 [ Search found 72 matches ]



Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software