| Author |
Message |
Forum: Simulation and emulation Topic: Simulating the Gigatron TTL Computer in a Logic Simulator. |
| monsonite |
|
Posted: Wed Aug 04, 2021 2:16 pm
|
|
Replies: 2
Views: 11953
|
| The Gigatron TTL Computer is an 8-bit Harvard architecture cpu built from about 40 TTL ICs plus a modern 64K x 16-bit ROM and a 32K x 8 RAM. I have owned a Gigatron for a few years, but only just got around to transcribing it's schematic into a Logic Simulator. I have placed a copy of my Gigatron si... |
|
 |
Forum: Hardware in general Topic: LED Transistor Logic - LTL |
| monsonite |
|
Posted: Mon May 03, 2021 11:33 pm
|
|
Replies: 3
Views: 2110
|
That's a good selection Ed,
Should keep me in reading material until I get my second jab! |
|
|
Forum: Hardware in general Topic: LED Transistor Logic - LTL |
| monsonite |
|
Posted: Mon May 03, 2021 12:30 pm
|
|
Replies: 3
Views: 2110
|
| A project recently spotted in the hackaday.io pages, by cpu enthusiast Tim Boscke. A "new-old" logic family based on LEDs and transistors, and a complete bitslice cpu implementation based on these discrete logic gates. Background. In the mid-1960s before ICs were widely incorporated into c... |
|
|
Forum: Languages and tools Topic: STABLE - a fast and small VM interpreter |
| monsonite |
|
Posted: Thu Apr 01, 2021 12:21 pm
|
|
Replies: 0
Views: 19980
|
| This project drew some attention on my Facebook Forth Programming Group. https://w3group.de/stable.html Written in C by Hungarian Sandor Schneider, its a VM interpreter for a stack machine that uses single character ascii codes as its instruction set. Although highly influenced by Forth, it is not F... |
|
|
Forum: Languages and tools Topic: Forth for Raspberry Pi Pico |
| monsonite |
|
Posted: Fri Feb 26, 2021 12:03 pm
|
|
Replies: 3
Views: 3395
|
| Yes, Stellaris was appropriate a few years ago when first ported to the TI Stellaris ARM Cortex M boards, - prior to that it had been MSP430. But, as is the nature of ARM devices, for a given core, you are dealing with a common instruction set, and the assembler and compiler tools appear to be virtu... |
|
|
Forum: Languages and tools Topic: Forth for Raspberry Pi Pico |
| monsonite |
|
Posted: Fri Feb 26, 2021 10:59 am
|
|
Replies: 3
Views: 3395
|
|
|
Forum: General Discussions Topic: Early HP Calculator Technology |
| monsonite |
|
Posted: Thu Feb 25, 2021 7:15 pm
|
|
Replies: 6
Views: 4170
|
| I have been looking at Ken Schiriff's reverse engineering of the Sinclair Scientific Calculator - from about 1974. http://files.righto.com/calculator/sinclair_scientific_simulator.html This document is well known amongst the hacker community, as Clive Sinclair's calculator development team (mostly N... |
|
|
Forum: General Discussions Topic: Early HP Calculator Technology |
| monsonite |
|
Posted: Thu Feb 25, 2021 12:49 am
|
|
Replies: 6
Views: 4170
|
The HP-35 featured in the June 1972 edition of the HP Journal
http://hparchive.com/Journals/HPJ-1972-06.pdf
Good information if you want a broader idea of how engineering calculations ( previously on a slide rule) were revolutionised by the HP-35. |
|
|
Forum: General Discussions Topic: Early HP Calculator Technology |
| monsonite |
|
Posted: Wed Feb 24, 2021 6:58 pm
|
|
Replies: 6
Views: 4170
|
Tom Osborne developed the "Green Machine" that ultimately became the HP 9100A.
Tom went on to work on the HP-35 and the programmable HP-65.
Here's a 1994 article describing his part in the projects:
http://www.hp9825.com/html/osborne_s_story.html |
|
|
Forum: General Discussions Topic: Early HP Calculator Technology |
| monsonite |
|
Posted: Wed Feb 24, 2021 6:11 pm
|
|
Replies: 6
Views: 4170
|
| . Nice thread! Have you seen Peter Monta's work? Reverse-engineering the HP-35 Yes, Ed, I spotted that earlier this morning. Amazing that you can use a microscope/photomicrographs to "read" the ROM contents from ROMs of that era. There is a wealth of HP-35 (and later models) information b... |
|
|
Forum: General Discussions Topic: Early HP Calculator Technology |
| monsonite |
|
Posted: Wed Feb 24, 2021 3:27 pm
|
|
Replies: 6
Views: 4170
|
| This is a follow-on from my late 1960s calculator discussion. It covers the progression from discrete transistor technology, through SSI, MSI and ultimately LSI devices - specifically those used by Hewlett Packard in the very early 1970s. HP had released a transistor based programmable, scientific d... |
|
|
Forum: General Discussions Topic: Late 1960s Calculator Technology |
| monsonite |
|
Posted: Tue Feb 23, 2021 1:34 am
|
|
Replies: 6
Views: 3691
|
| Pico Electronics Ltd - the unknown UK calculator chip manufacturer. Founded in summer 1970 in Glenrothes, Scotland, out of the wreckage of Elliott Automation, Pico were possibly the first company to have a single chip calculator. https://www.xnumber.com/xnumber/microprocessor_history.htm Pico's pate... |
|
|
Forum: General Discussions Topic: Late 1960s Calculator Technology |
| monsonite |
|
Posted: Tue Feb 23, 2021 12:21 am
|
|
Replies: 6
Views: 3691
|
| I imagine engineers of the day would be very familiar with mechanical calculators, as users, and perhaps also know something of the mechanisms, so digit-serial actions would be relatively natural, as would digit-by-digit shifting. The engineers of that time would also have been familiar with early ... |
|
|
Forum: General Discussions Topic: Late 1960s Calculator Technology |
| monsonite |
|
Posted: Mon Feb 22, 2021 6:21 pm
|
|
Replies: 6
Views: 3691
|
| Ed, I must admit calculator history is a fascinating "rabbit hole". I was seeking inspiration for my bit-serial cpu architecture and discovered a whole tranche of technical iinformation about late 1960s calculators and the move from SSI and MSI to LSI. A bit serial adder/subtractor might a... |
|
|
Forum: General Discussions Topic: Late 1960s Calculator Technology |
| monsonite |
|
Posted: Mon Feb 22, 2021 4:50 pm
|
|
Replies: 6
Views: 3691
|
| Desktop calculators produced in Japan from 1968 to roughly 1971 present a unique snapshot of electronic computing technology. This was the age of the minicomputer (PDP-8, PDP-11, DG Nova etc) and these machines represented an investment of tens of thousands of dollars. For the office and business en... |
|
|
| Sort by: |
