Interisting info there aabout those old calculators.
Do you happen to kniw what kind of CPU the Sinclair Cambridge Programmable had? I used to have one of those (broke years ago) and would like to see emulator for it.
According to Vintage Calculators, the Sinclair Cambridge Programmable uses the National Semiconductor MM5799EHY/N and DS7784N. I don't know anything about those chips. But stay tuned for more about the Sinclair Scientific.
Ed and anonymous: the links should work now. Thanks for letting me know.
April 6, 2018 at 3:32 PM
I've built a register-level simulator of a 1974 TI calculator chip that shows what actually happens inside a calculator when you perform operations and shows the calculator source code as it executes. The architecture of the calculator chip is pretty interesting, with 11-bit opcodes, a 9-bit address bus, and 44-bit BCD registers. The chip doesn't support multiplication or division, so these are performed with repeated addition or subtraction.
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The simulator is at righto.com/ti.
posted by Ken Shirriff at 10:50 AM on Aug 11, 2013
"Simulating a TI calculator with crazy 11-bit opcodes"
5 Comments -
Interisting info there aabout those old calculators.
Do you happen to kniw what kind of CPU the Sinclair Cambridge Programmable had? I used to have one of those (broke years ago) and would like to see emulator for it.
August 11, 2013 at 6:53 PM
According to Vintage Calculators, the Sinclair Cambridge Programmable uses the National Semiconductor MM5799EHY/N and DS7784N. I don't know anything about those chips. But stay tuned for more about the Sinclair Scientific.
August 11, 2013 at 10:44 PM
Great stuff Ken!
But the linked schematic on Picasaweb is broken for me.
August 12, 2013 at 5:14 AM
The link to the emulator doesn't work.
April 5, 2018 at 12:58 AM
Ed and anonymous: the links should work now. Thanks for letting me know.
April 6, 2018 at 3:32 PM